Merge remote-tracking branch 'upstream/dev' into dev

2026-03-31 01:45:45 +00:00 · 2025-09-21 08:28:16 -07:00
parent 2536fa6bcf 695473f842
commit 7b3a0bba97
40 changed files with 1186 additions and 456 deletions
--- a/boards/ebyte_eora-s3.json
+++ b/boards/ebyte_eora-s3.json
@@ -0,0 +1,45 @@
+{
+  "build": {
+    "arduino": {
+      "ldscript": "esp32s3_out.ld",
+      "partitions": "default.csv",
+      "memory_type": "qio_qspi"
+    },
+    "core": "esp32",
+    "extra_flags": [
+      "-DARDUINO_LILYGO_T3_S3_V1_X",
+      "-DBOARD_HAS_PSRAM",
+      "-DARDUINO_USB_CDC_ON_BOOT=1",
+      "-DARDUINO_RUNNING_CORE=1",
+      "-DARDUINO_EVENT_RUNNING_CORE=1",
+      "-DARDUINO_USB_MODE=1"
+    ],
+    "f_cpu": "240000000L",
+    "f_flash": "80000000L",
+    "flash_mode": "qio",
+    "mcu": "esp32s3",
+    "variant": "esp32s3"
+  },
+  "connectivity": [
+    "wifi"
+  ],
+  "debug": {
+    "openocd_target": "esp32s3.cfg"
+  },
+  "frameworks": [
+    "arduino",
+    "espidf"
+  ],
+  "name": "Ebyte EoRa-S3-XXXTB Radio",
+  "upload": {
+    "flash_size": "4MB",
+    "maximum_ram_size": 327680,
+    "maximum_size": 4194304,
+    "use_1200bps_touch": true,
+    "wait_for_upload_port": true,
+    "require_upload_port": true,
+    "speed": 460800
+  },
+  "url": "https://www.cdebyte.com/products/EoRa-S3-900TB",
+  "vendor": "Chengdu Ebyte Electronic Technology Co., Ltd"
+}
--- a/boards/tiny_relay.json
+++ b/boards/tiny_relay.json
@@ -0,0 +1,33 @@
+{
+  "build": {
+    "arduino": {
+      "variant_h": "variant_RAK3172_MODULE.h"
+    },
+    "core": "stm32",
+    "cpu": "cortex-m4",
+    "extra_flags": "-DSTM32WL -DSTM32WLxx -DSTM32WLE5xx",
+    "framework_extra_flags": {
+      "arduino": "-DUSE_CM4_STARTUP_FILE -DARDUINO_RAK3172_MODULE"
+    },
+    "f_cpu": "48000000L",
+    "mcu": "stm32wle5ccu",
+    "product_line": "STM32WLE5xx",
+    "variant": "STM32WLxx/WL54CCU_WL55CCU_WLE4C(8-B-C)U_WLE5C(8-B-C)U"
+  },
+  "debug": {
+    "default_tools": ["stlink"],
+    "jlink_device": "STM32WLE5CC",
+    "openocd_target": "stm32wlx",
+    "svd_path": "STM32WLE5_CM4.svd"
+  },
+  "frameworks": ["arduino"],
+  "name": "BB-STM32WL",
+  "upload": {
+    "maximum_ram_size": 65536,
+    "maximum_size": 262144,
+    "protocol": "stlink",
+    "protocols": ["stlink", "jlink"]
+  },
+  "url": "https://www.st.com/en/microcontrollers-microprocessors/stm32wle5cc.html",
+  "vendor": "YAOYAO"
+}
--- a/examples/companion_radio/AbstractUITask.h
+++ b/examples/companion_radio/AbstractUITask.h
@@ -41,6 +41,6 @@ public:
  void disableSerial() { _serial->disable(); }
  virtual void msgRead(int msgcount) = 0;
  virtual void newMsg(uint8_t path_len, const char* from_name, const char* text, int msgcount) = 0;
-  virtual void soundBuzzer(UIEventType bet = UIEventType::none) = 0;
+  virtual void notify(UIEventType t = UIEventType::none) = 0;
  virtual void loop() = 0;
 };
--- a/examples/companion_radio/DataStore.cpp
+++ b/examples/companion_radio/DataStore.cpp
@@ -42,12 +42,17 @@ static File openWrite(FILESYSTEM* fs, const char* filename) {
 #endif
 }

+#if defined(NRF52_PLATFORM) || defined(STM32_PLATFORM)
+  static uint32_t _ContactsChannelsTotalBlocks = 0;
+#endif
+
 void DataStore::begin() {
 #if defined(RP2040_PLATFORM)
  identity_store.begin();
 #endif

 #if defined(NRF52_PLATFORM) || defined(STM32_PLATFORM)
+  _ContactsChannelsTotalBlocks = _getContactsChannelsFS()->_getFS()->cfg->block_count;
  checkAdvBlobFile();
  #if defined(EXTRAFS) || defined(QSPIFLASH)
  migrateToSecondaryFS();
@@ -74,14 +79,22 @@ void DataStore::begin() {

 #if defined(NRF52_PLATFORM) || defined(STM32_PLATFORM)
 int _countLfsBlock(void *p, lfs_block_t block){
+      if (block > _ContactsChannelsTotalBlocks) {
+        MESH_DEBUG_PRINTLN("ERROR: Block %d exceeds filesystem bounds - CORRUPTION DETECTED!", block);
+        return LFS_ERR_CORRUPT;  // return error to abort lfs_traverse() gracefully
+    }
  lfs_size_t *size = (lfs_size_t*) p;
  *size += 1;
-  return 0;
+    return 0;
 }

 lfs_ssize_t _getLfsUsedBlockCount(FILESYSTEM* fs) {
  lfs_size_t size = 0;
-  lfs_traverse(fs->_getFS(), _countLfsBlock, &size);
+  int err = lfs_traverse(fs->_getFS(), _countLfsBlock, &size);
+  if (err) {
+    MESH_DEBUG_PRINTLN("ERROR: lfs_traverse() error: %d", err);
+    return 0;
+  }
  return size;
 }
 #endif
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -243,7 +243,7 @@ void MyMesh::onDiscoveredContact(ContactInfo &contact, bool is_new, uint8_t path
    }
  } else {
 #ifdef DISPLAY_CLASS
-    if (_ui) _ui->soundBuzzer(UIEventType::newContactMessage);
+    if (_ui) _ui->notify(UIEventType::newContactMessage);
 #endif
  }

@@ -294,7 +294,7 @@ void MyMesh::onContactPathUpdated(const ContactInfo &contact) {
  dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
 }

-bool MyMesh::processAck(const uint8_t *data) {
+ContactInfo*  MyMesh::processAck(const uint8_t *data) {
  // see if matches any in a table
  for (int i = 0; i < EXPECTED_ACK_TABLE_SIZE; i++) {
    if (memcmp(data, &expected_ack_table[i].ack, 4) == 0) { // got an ACK from recipient
@@ -306,7 +306,7 @@ bool MyMesh::processAck(const uint8_t *data) {

      // NOTE: the same ACK can be received multiple times!
      expected_ack_table[i].ack = 0; // clear expected hash, now that we have received ACK
-      return true;
+      return expected_ack_table[i].contact;
    }
  }
  return checkConnectionsAck(data);
@@ -353,7 +353,7 @@ void MyMesh::queueMessage(const ContactInfo &from, uint8_t txt_type, mesh::Packe
  if (should_display && _ui) {
    _ui->newMsg(path_len, from.name, text, offline_queue_len);
    if (!_serial->isConnected()) {
-      _ui->soundBuzzer(UIEventType::contactMessage);
+      _ui->notify(UIEventType::contactMessage);
    }
  }
 #endif
@@ -412,7 +412,7 @@ void MyMesh::onChannelMessageRecv(const mesh::GroupChannel &channel, mesh::Packe
    _serial->writeFrame(frame, 1);
  } else {
 #ifdef DISPLAY_CLASS
-    if (_ui) _ui->soundBuzzer(UIEventType::channelMessage);
+    if (_ui) _ui->notify(UIEventType::channelMessage);
 #endif
  }
 #ifdef DISPLAY_CLASS
@@ -825,6 +825,7 @@ void MyMesh::handleCmdFrame(size_t len) {
        if (expected_ack) {
          expected_ack_table[next_ack_idx].msg_sent = _ms->getMillis(); // add to circular table
          expected_ack_table[next_ack_idx].ack = expected_ack;
+          expected_ack_table[next_ack_idx].contact = recipient;
          next_ack_idx = (next_ack_idx + 1) % EXPECTED_ACK_TABLE_SIZE;
        }

--- a/examples/companion_radio/MyMesh.h
+++ b/examples/companion_radio/MyMesh.h
@@ -112,7 +112,7 @@ protected:
  bool onContactPathRecv(ContactInfo& from, uint8_t* in_path, uint8_t in_path_len, uint8_t* out_path, uint8_t out_path_len, uint8_t extra_type, uint8_t* extra, uint8_t extra_len) override;
  void onDiscoveredContact(ContactInfo &contact, bool is_new, uint8_t path_len, const uint8_t* path) override;
  void onContactPathUpdated(const ContactInfo &contact) override;
-  bool processAck(const uint8_t *data) override;
+  ContactInfo* processAck(const uint8_t *data) override;
  void queueMessage(const ContactInfo &from, uint8_t txt_type, mesh::Packet *pkt, uint32_t sender_timestamp,
                    const uint8_t *extra, int extra_len, const char *text);

@@ -205,6 +205,7 @@ private:
  struct AckTableEntry {
    unsigned long msg_sent;
    uint32_t ack;
+    ContactInfo* contact;
  };
  #define EXPECTED_ACK_TABLE_SIZE 8
  AckTableEntry expected_ack_table[EXPECTED_ACK_TABLE_SIZE]; // circular table
--- a/examples/companion_radio/ui-new/UITask.cpp
+++ b/examples/companion_radio/ui-new/UITask.cpp
@@ -90,6 +90,7 @@ class HomeScreen : public UIScreen {
  bool _shutdown_init;
  AdvertPath recent[UI_RECENT_LIST_SIZE];

+
  void renderBatteryIndicator(DisplayDriver& display, uint16_t batteryMilliVolts) {
    // Convert millivolts to percentage
    const int minMilliVolts = 3000; // Minimum voltage (e.g., 3.0V)
@@ -157,10 +158,12 @@ public:
  int render(DisplayDriver& display) override {
    char tmp[80];
    // node name
-    display.setCursor(0, 0);
    display.setTextSize(1);
    display.setColor(DisplayDriver::GREEN);
-    display.print(_node_prefs->node_name);
+    char filtered_name[sizeof(_node_prefs->node_name)];
+    display.translateUTF8ToBlocks(filtered_name, _node_prefs->node_name, sizeof(filtered_name));
+    display.setCursor(0, 0);
+    display.print(filtered_name);

    // battery voltage
    renderBatteryIndicator(display, _task->getBattMilliVolts());
@@ -199,8 +202,6 @@ public:
      for (int i = 0; i < UI_RECENT_LIST_SIZE; i++, y += 11) {
        auto a = &recent[i];
        if (a->name[0] == 0) continue;  // empty slot
-        display.setCursor(0, y);
-        display.print(a->name);
        int secs = _rtc->getCurrentTime() - a->recv_timestamp;
        if (secs < 60) {
          sprintf(tmp, "%ds", secs);
@@ -209,7 +210,14 @@ public:
        } else {
          sprintf(tmp, "%dh", secs / (60*60));
        }
-        display.setCursor(display.width() - display.getTextWidth(tmp) - 1, y);
+        
+        int timestamp_width = display.getTextWidth(tmp);
+        int max_name_width = display.width() - timestamp_width - 1;
+        
+        char filtered_recent_name[sizeof(a->name)];
+        display.translateUTF8ToBlocks(filtered_recent_name, a->name, sizeof(filtered_recent_name));
+        display.drawTextEllipsized(0, y, max_name_width, filtered_recent_name);
+        display.setCursor(display.width() - timestamp_width - 1, y);
        display.print(tmp);
      }
    } else if (_page == HomePage::RADIO) {
@@ -348,9 +356,7 @@ public:
      return true;
    }
    if (c == KEY_ENTER && _page == HomePage::ADVERT) {
-  #ifdef PIN_BUZZER
-      _task->soundBuzzer(UIEventType::ack);
-  #endif
+      _task->notify(UIEventType::ack);
      if (the_mesh.advert()) {
        _task->showAlert("Advert sent!", 1000);
      } else {
@@ -427,11 +433,15 @@ public:

    display.setCursor(0, 14);
    display.setColor(DisplayDriver::YELLOW);
-    display.print(p->origin);
+    char filtered_origin[sizeof(p->origin)];
+    display.translateUTF8ToBlocks(filtered_origin, p->origin, sizeof(filtered_origin));
+    display.print(filtered_origin);

    display.setCursor(0, 25);
    display.setColor(DisplayDriver::LIGHT);
-    display.printWordWrap(p->msg, display.width());
+    char filtered_msg[sizeof(p->msg)];
+    display.translateUTF8ToBlocks(filtered_msg, p->msg, sizeof(filtered_msg));
+    display.printWordWrap(filtered_msg, display.width());

 #if AUTO_OFF_MILLIS==0 // probably e-ink
    return 10000; // 10 s
@@ -483,6 +493,10 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, NodePrefs* no
  buzzer.begin();
 #endif

+#ifdef PIN_VIBRATION
+  vibration.begin();
+#endif
+
  ui_started_at = millis();
  _alert_expiry = 0;

@@ -497,9 +511,9 @@ void UITask::showAlert(const char* text, int duration_millis) {
  _alert_expiry = millis() + duration_millis;
 }

-void UITask::soundBuzzer(UIEventType bet) {
+void UITask::notify(UIEventType t) {
 #if defined(PIN_BUZZER)
-switch(bet){
+switch(t){
  case UIEventType::contactMessage:
    // gemini's pick
    buzzer.play("MsgRcv3:d=4,o=6,b=200:32e,32g,32b,16c7");
@@ -517,8 +531,16 @@ switch(bet){
    break;
 }
 #endif
+
+#ifdef PIN_VIBRATION
+  // Trigger vibration for all UI events except none
+  if (t != UIEventType::none) {
+    vibration.trigger();
+  }
+#endif
 }

+
 void UITask::msgRead(int msgcount) {
  _msgcount = msgcount;
  if (msgcount == 0) {
@@ -687,6 +709,10 @@ void UITask::loop() {
 #endif
  }

+#ifdef PIN_VIBRATION
+  vibration.loop();
+#endif
+
 #ifdef AUTO_SHUTDOWN_MILLIVOLTS
  if (millis() > next_batt_chck) {
    uint16_t milliVolts = getBattMilliVolts();
@@ -755,11 +781,11 @@ void UITask::toggleGPS() {
      if (strcmp(_sensors->getSettingName(i), "gps") == 0) {
        if (strcmp(_sensors->getSettingValue(i), "1") == 0) {
          _sensors->setSettingValue("gps", "0");
-          soundBuzzer(UIEventType::ack);
+          notify(UIEventType::ack);
          showAlert("GPS: Disabled", 800);
        } else {
          _sensors->setSettingValue("gps", "1");
-          soundBuzzer(UIEventType::ack);
+          notify(UIEventType::ack);
          showAlert("GPS: Enabled", 800);
        }
        _next_refresh = 0;
@@ -774,7 +800,7 @@ void UITask::toggleBuzzer() {
  #ifdef PIN_BUZZER
    if (buzzer.isQuiet()) {
      buzzer.quiet(false);
-      soundBuzzer(UIEventType::ack);
+      notify(UIEventType::ack);
      showAlert("Buzzer: ON", 800);
    } else {
      buzzer.quiet(true);
--- a/examples/companion_radio/ui-new/UITask.h
+++ b/examples/companion_radio/ui-new/UITask.h
@@ -11,6 +11,9 @@
 #ifdef PIN_BUZZER
  #include <helpers/ui/buzzer.h>
 #endif
+#ifdef PIN_VIBRATION
+  #include <helpers/ui/GenericVibration.h>
+#endif

 #include "../AbstractUITask.h"
 #include "../NodePrefs.h"
@@ -20,6 +23,9 @@ class UITask : public AbstractUITask {
  SensorManager* _sensors;
 #ifdef PIN_BUZZER
  genericBuzzer buzzer;
+#endif
+#ifdef PIN_VIBRATION
+  GenericVibration vibration;
 #endif
  unsigned long _next_refresh, _auto_off;
  NodePrefs* _node_prefs;
@@ -71,7 +77,7 @@ public:
  // from AbstractUITask
  void msgRead(int msgcount) override;
  void newMsg(uint8_t path_len, const char* from_name, const char* text, int msgcount) override;
-  void soundBuzzer(UIEventType bet = UIEventType::none) override;
+  void notify(UIEventType t = UIEventType::none) override;
  void loop() override;

  void shutdown(bool restart = false);
--- a/examples/companion_radio/ui-orig/UITask.cpp
+++ b/examples/companion_radio/ui-orig/UITask.cpp
@@ -88,9 +88,9 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, NodePrefs* no
  ui_started_at = millis();
 }

-void UITask::soundBuzzer(UIEventType bet) {
+void UITask::notify(UIEventType t) {
 #if defined(PIN_BUZZER)
-switch(bet){
+switch(t){
  case UIEventType::contactMessage:
    // gemini's pick
    buzzer.play("MsgRcv3:d=4,o=6,b=200:32e,32g,32b,16c7");
@@ -108,8 +108,8 @@ switch(bet){
    break;
 }
 #endif
-//  Serial.print("DBG:  Buzzzzzz -> ");
-//  Serial.println((int) bet);
+//  Serial.print("DBG:  Alert user -> ");
+//  Serial.println((int) t);
 }

 void UITask::msgRead(int msgcount) {
@@ -370,7 +370,7 @@ void UITask::handleButtonDoublePress() {
  MESH_DEBUG_PRINTLN("UITask: double press triggered, sending advert");
  // ADVERT
  #ifdef PIN_BUZZER
-      soundBuzzer(UIEventType::ack);
+      notify(UIEventType::ack);
  #endif
  if (the_mesh.advert()) {
    MESH_DEBUG_PRINTLN("Advert sent!");
@@ -388,7 +388,7 @@ void UITask::handleButtonTriplePress() {
  #ifdef PIN_BUZZER
    if (buzzer.isQuiet()) {
      buzzer.quiet(false);
-      soundBuzzer(UIEventType::ack);
+      notify(UIEventType::ack);
      sprintf(_alert, "Buzzer: ON");
    } else {
      buzzer.quiet(true);
@@ -407,11 +407,11 @@ void UITask::handleButtonQuadruplePress() {
      if (strcmp(_sensors->getSettingName(i), "gps") == 0) {
        if (strcmp(_sensors->getSettingValue(i), "1") == 0) {
          _sensors->setSettingValue("gps", "0");
-          soundBuzzer(UIEventType::ack);
+          notify(UIEventType::ack);
          sprintf(_alert, "GPS: Disabled");
        } else {
          _sensors->setSettingValue("gps", "1");
-          soundBuzzer(UIEventType::ack);
+          notify(UIEventType::ack);
          sprintf(_alert, "GPS: Enabled");
        }
        break;
--- a/examples/companion_radio/ui-orig/UITask.h
+++ b/examples/companion_radio/ui-orig/UITask.h
@@ -66,7 +66,7 @@ public:
  // from AbstractUITask
  void msgRead(int msgcount) override;
  void newMsg(uint8_t path_len, const char* from_name, const char* text, int msgcount) override;
-  void soundBuzzer(UIEventType bet = UIEventType::none) override;
+  void notify(UIEventType t = UIEventType::none) override;
  void loop() override;

  void shutdown(bool restart = false);
--- a/examples/simple_repeater/MyMesh.cpp
+++ b/examples/simple_repeater/MyMesh.cpp
@@ -43,28 +43,13 @@
 #define REQ_TYPE_GET_STATUS         0x01 // same as _GET_STATS
 #define REQ_TYPE_KEEP_ALIVE         0x02
 #define REQ_TYPE_GET_TELEMETRY_DATA 0x03
+#define REQ_TYPE_GET_ACCESS_LIST    0x05

 #define RESP_SERVER_LOGIN_OK        0 // response to ANON_REQ

 #define CLI_REPLY_DELAY_MILLIS      600

-
-ClientInfo *MyMesh::putClient(const mesh::Identity &id) {
-  uint32_t min_time = 0xFFFFFFFF;
-  ClientInfo *oldest = &known_clients[0];
-  for (int i = 0; i < MAX_CLIENTS; i++) {
-    if (known_clients[i].last_activity < min_time) {
-      oldest = &known_clients[i];
-      min_time = oldest->last_activity;
-    }
-    if (id.matches(known_clients[i].id)) return &known_clients[i]; // already known
-  }
-
-  oldest->id = id;
-  oldest->out_path_len = -1; // initially out_path is unknown
-  oldest->last_timestamp = 0;
-  return oldest;
-}
+#define LAZY_CONTACTS_WRITE_DELAY    5000

 void MyMesh::putNeighbour(const mesh::Identity &id, uint32_t timestamp, float snr) {
 #if MAX_NEIGHBOURS // check if neighbours enabled
@@ -93,15 +78,61 @@ void MyMesh::putNeighbour(const mesh::Identity &id, uint32_t timestamp, float sn
 #endif
 }

-int MyMesh::handleRequest(ClientInfo *sender, uint32_t sender_timestamp, uint8_t *payload,
-                          size_t payload_len) {
+uint8_t MyMesh::handleLoginReq(const mesh::Identity& sender, const uint8_t* secret, uint32_t sender_timestamp, const uint8_t* data) {
+  ClientInfo* client;
+  if (data[0] == 0) {   // blank password, just check if sender is in ACL
+    client = acl.getClient(sender.pub_key, PUB_KEY_SIZE);
+    if (client == NULL) {
+    #if MESH_DEBUG
+      MESH_DEBUG_PRINTLN("Login, sender not in ACL");
+    #endif
+      return 0;
+    }
+  } else {
+    uint8_t perms;
+    if (strcmp((char *)data, _prefs.password) == 0) { // check for valid admin password
+      perms = PERM_ACL_ADMIN;
+    } else if (strcmp((char *)data, _prefs.guest_password) == 0) { // check guest password
+      perms = PERM_ACL_GUEST;
+    } else {
+#if MESH_DEBUG
+      MESH_DEBUG_PRINTLN("Invalid password: %s", data);
+#endif
+      return 0;
+    }
+
+    client = acl.putClient(sender, 0);  // add to contacts (if not already known)
+    if (sender_timestamp <= client->last_timestamp) {
+      MESH_DEBUG_PRINTLN("Possible login replay attack!");
+      return 0;  // FATAL: client table is full -OR- replay attack
+    }
+
+    MESH_DEBUG_PRINTLN("Login success!");
+    client->last_timestamp = sender_timestamp;
+    client->last_activity = getRTCClock()->getCurrentTime();
+    client->permissions |= perms;
+    memcpy(client->shared_secret, secret, PUB_KEY_SIZE);
+
+    dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
+  }
+
+  uint32_t now = getRTCClock()->getCurrentTimeUnique();
+  memcpy(reply_data, &now, 4);   // response packets always prefixed with timestamp
+  reply_data[4] = RESP_SERVER_LOGIN_OK;
+  reply_data[5] = 0;  // NEW: recommended keep-alive interval (secs / 16)
+  reply_data[6] = client->isAdmin() ? 1 : 0;
+  reply_data[7] = client->permissions;
+  getRNG()->random(&reply_data[8], 4);   // random blob to help packet-hash uniqueness
+
+  return 12;  // reply length
+}
+
+int MyMesh::handleRequest(ClientInfo *sender, uint32_t sender_timestamp, uint8_t *payload, size_t payload_len) {
  // uint32_t now = getRTCClock()->getCurrentTimeUnique();
  // memcpy(reply_data, &now, 4);   // response packets always prefixed with timestamp
-  memcpy(reply_data, &sender_timestamp,
-         4); // reflect sender_timestamp back in response packet (kind of like a 'tag')
+  memcpy(reply_data, &sender_timestamp, 4); // reflect sender_timestamp back in response packet (kind of like a 'tag')

-  switch (payload[0]) {
-  case REQ_TYPE_GET_STATUS: { // guests can also access this now
+  if (payload[0] == REQ_TYPE_GET_STATUS) {  // guests can also access this now
    RepeaterStats stats;
    stats.batt_milli_volts = board.getBattMilliVolts();
    stats.curr_tx_queue_len = _mgr->getOutboundCount(0xFFFFFFFF);
@@ -125,18 +156,31 @@ int MyMesh::handleRequest(ClientInfo *sender, uint32_t sender_timestamp, uint8_t

    return 4 + sizeof(stats); //  reply_len
  }
-  case REQ_TYPE_GET_TELEMETRY_DATA: {
+  if (payload[0] == REQ_TYPE_GET_TELEMETRY_DATA) {
    uint8_t perm_mask = ~(payload[1]); // NEW: first reserved byte (of 4), is now inverse mask to apply to permissions

    telemetry.reset();
    telemetry.addVoltage(TELEM_CHANNEL_SELF, (float)board.getBattMilliVolts() / 1000.0f);
    // query other sensors -- target specific
-    sensors.querySensors((sender->is_admin ? 0xFF : 0x00) & perm_mask, telemetry);
+    sensors.querySensors((sender->isAdmin() ? 0xFF : 0x00) & perm_mask, telemetry);

    uint8_t tlen = telemetry.getSize();
    memcpy(&reply_data[4], telemetry.getBuffer(), tlen);
    return 4 + tlen; // reply_len
  }
+  if (payload[0] == REQ_TYPE_GET_ACCESS_LIST && sender->isAdmin()) {
+    uint8_t res1 = payload[1];   // reserved for future  (extra query params)
+    uint8_t res2 = payload[2];
+    if (res1 == 0 && res2 == 0) {
+      uint8_t ofs = 4;
+      for (int i = 0; i < acl.getNumClients() && ofs + 7 <= sizeof(reply_data) - 4; i++) {
+        auto c = acl.getClientByIdx(i);
+        if (c->permissions == 0) continue;  // skip deleted entries
+        memcpy(&reply_data[ofs], c->id.pub_key, 6); ofs += 6;  // just 6-byte pub_key prefix
+        reply_data[ofs++] = c->permissions;
+      }
+      return ofs;
+    }
  }
  return 0; // unknown command
 }
@@ -261,65 +305,26 @@ void MyMesh::onAnonDataRecv(mesh::Packet *packet, const uint8_t *secret, const m
    uint32_t timestamp;
    memcpy(&timestamp, data, 4);

-    bool is_admin;
-    data[len] = 0;                                        // ensure null terminator
-    if (strcmp((char *)&data[4], _prefs.password) == 0) { // check for valid password
-      is_admin = true;
-    } else if (strcmp((char *)&data[4], _prefs.guest_password) == 0) { // check guest password
-      is_admin = false;
-    } else {
-#if MESH_DEBUG
-      MESH_DEBUG_PRINTLN("Invalid password: %s", &data[4]);
-#endif
-      return;
-    }
+    uint8_t reply_len = handleLoginReq(sender, secret, timestamp, &data[4]);

-    auto client = putClient(sender); // add to known clients (if not already known)
-    if (timestamp <= client->last_timestamp) {
-      MESH_DEBUG_PRINTLN("Possible login replay attack!");
-      return; // FATAL: client table is full -OR- replay attack
-    }
-
-    MESH_DEBUG_PRINTLN("Login success!");
-    client->last_timestamp = timestamp;
-    client->last_activity = getRTCClock()->getCurrentTime();
-    client->is_admin = is_admin;
-    memcpy(client->secret, secret, PUB_KEY_SIZE);
-
-    uint32_t now = getRTCClock()->getCurrentTimeUnique();
-    memcpy(reply_data, &now, 4); // response packets always prefixed with timestamp
-#if 0
-      memcpy(&reply_data[4], "OK", 2);   // legacy response
-#else
-    reply_data[4] = RESP_SERVER_LOGIN_OK;
-    reply_data[5] = 0; // NEW: recommended keep-alive interval (secs / 16)
-    reply_data[6] = is_admin ? 1 : 0;
-    reply_data[7] = 0;                   // FUTURE: reserved
-    getRNG()->random(&reply_data[8], 4); // random blob to help packet-hash uniqueness
-#endif
+    if (reply_len == 0) return;   // invalid request

    if (packet->isRouteFlood()) {
      // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the response
-      mesh::Packet *path = createPathReturn(sender, client->secret, packet->path, packet->path_len,
-                                            PAYLOAD_TYPE_RESPONSE, reply_data, 12);
+      mesh::Packet* path = createPathReturn(sender, secret, packet->path, packet->path_len,
+                                            PAYLOAD_TYPE_RESPONSE, reply_data, reply_len);
      if (path) sendFlood(path, SERVER_RESPONSE_DELAY);
    } else {
-      mesh::Packet *reply = createDatagram(PAYLOAD_TYPE_RESPONSE, sender, client->secret, reply_data, 12);
-      if (reply) {
-        if (client->out_path_len >= 0) { // we have an out_path, so send DIRECT
-          sendDirect(reply, client->out_path, client->out_path_len, SERVER_RESPONSE_DELAY);
-        } else {
-          sendFlood(reply, SERVER_RESPONSE_DELAY);
-        }
-      }
+      mesh::Packet* reply = createDatagram(PAYLOAD_TYPE_RESPONSE, sender, secret, reply_data, reply_len);
+      if (reply) sendFlood(reply, SERVER_RESPONSE_DELAY);
    }
  }
 }

 int MyMesh::searchPeersByHash(const uint8_t *hash) {
  int n = 0;
-  for (int i = 0; i < MAX_CLIENTS; i++) {
-    if (known_clients[i].id.isHashMatch(hash)) {
+  for (int i = 0; i < acl.getNumClients(); i++) {
+    if (acl.getClientByIdx(i)->id.isHashMatch(hash)) {
      matching_peer_indexes[n++] = i; // store the INDEXES of matching contacts (for subsequent 'peer' methods)
    }
  }
@@ -328,9 +333,9 @@ int MyMesh::searchPeersByHash(const uint8_t *hash) {

 void MyMesh::getPeerSharedSecret(uint8_t *dest_secret, int peer_idx) {
  int i = matching_peer_indexes[peer_idx];
-  if (i >= 0 && i < MAX_CLIENTS) {
+  if (i >= 0 && i < acl.getNumClients()) {
    // lookup pre-calculated shared_secret
-    memcpy(dest_secret, known_clients[i].secret, PUB_KEY_SIZE);
+    memcpy(dest_secret, acl.getClientByIdx(i)->shared_secret, PUB_KEY_SIZE);
  } else {
    MESH_DEBUG_PRINTLN("getPeerSharedSecret: Invalid peer idx: %d", i);
  }
@@ -352,12 +357,12 @@ void MyMesh::onAdvertRecv(mesh::Packet *packet, const mesh::Identity &id, uint32
 void MyMesh::onPeerDataRecv(mesh::Packet *packet, uint8_t type, int sender_idx, const uint8_t *secret,
                            uint8_t *data, size_t len) {
  int i = matching_peer_indexes[sender_idx];
-  if (i < 0 ||
-      i >= MAX_CLIENTS) { // get from our known_clients table (sender SHOULD already be known in this context)
+  if (i < 0 || i >= acl.getNumClients()) { // get from our known_clients table (sender SHOULD already be known in this context)
    MESH_DEBUG_PRINTLN("onPeerDataRecv: invalid peer idx: %d", i);
    return;
  }
-  auto client = &known_clients[i];
+  ClientInfo* client = acl.getClientByIdx(i);
+
  if (type == PAYLOAD_TYPE_REQ) { // request (from a Known admin client!)
    uint32_t timestamp;
    memcpy(&timestamp, data, 4);
@@ -388,7 +393,7 @@ void MyMesh::onPeerDataRecv(mesh::Packet *packet, uint8_t type, int sender_idx,
    } else {
      MESH_DEBUG_PRINTLN("onPeerDataRecv: possible replay attack detected");
    }
-  } else if (type == PAYLOAD_TYPE_TXT_MSG && len > 5 && client->is_admin) { // a CLI command
+  } else if (type == PAYLOAD_TYPE_TXT_MSG && len > 5 && client->isAdmin()) { // a CLI command
    uint32_t sender_timestamp;
    memcpy(&sender_timestamp, data, 4); // timestamp (by sender's RTC clock - which could be wrong)
    uint flags = (data[4] >> 2);        // message attempt number, and other flags
@@ -457,11 +462,12 @@ bool MyMesh::onPeerPathRecv(mesh::Packet *packet, int sender_idx, const uint8_t
  // TODO: prevent replay attacks
  int i = matching_peer_indexes[sender_idx];

-  if (i >= 0 &&
-      i < MAX_CLIENTS) { // get from our known_clients table (sender SHOULD already be known in this context)
+  if (i >= 0 && i < acl.getNumClients()) { // get from our known_clients table (sender SHOULD already be known in this context)
    MESH_DEBUG_PRINTLN("PATH to client, path_len=%d", (uint32_t)path_len);
-    auto client = &known_clients[i];
+    auto client = acl.getClientByIdx(i);
+
    memcpy(client->out_path, path, client->out_path_len = path_len); // store a copy of path, for sendDirect()
+    client->last_activity = getRTCClock()->getCurrentTime();
  } else {
    MESH_DEBUG_PRINTLN("onPeerPathRecv: invalid peer idx: %d", i);
  }
@@ -480,8 +486,8 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
      , bridge(_mgr, &rtc)
 #endif
 {
-  memset(known_clients, 0, sizeof(known_clients));
  next_local_advert = next_flood_advert = 0;
+  dirty_contacts_expiry = 0;
  set_radio_at = revert_radio_at = 0;
  _logging = false;

@@ -515,6 +521,8 @@ void MyMesh::begin(FILESYSTEM *fs) {
  // load persisted prefs
  _cli.loadPrefs(_fs);

+  acl.load(_fs);
+
 #ifdef WITH_BRIDGE
  bridge.begin();
 #endif
@@ -664,7 +672,43 @@ void MyMesh::handleCommand(uint32_t sender_timestamp, char *command, char *reply
    command += 3;
  }

-  _cli.handleCommand(sender_timestamp, command, reply); // common CLI commands
+  // handle ACL related commands
+  if (memcmp(command, "setperm ", 8) == 0) {   // format:  setperm {pubkey-hex} {permissions-int8}
+    char* hex = &command[8];
+    char* sp = strchr(hex, ' ');   // look for separator char
+    if (sp == NULL) {
+      strcpy(reply, "Err - bad params");
+    } else {
+      *sp++ = 0;   // replace space with null terminator
+
+      uint8_t pubkey[PUB_KEY_SIZE];
+      int hex_len = min(sp - hex, PUB_KEY_SIZE*2);
+      if (mesh::Utils::fromHex(pubkey, hex_len / 2, hex)) {
+        uint8_t perms = atoi(sp);
+        if (acl.applyPermissions(self_id, pubkey, hex_len / 2, perms)) {
+          dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);   // trigger acl.save()
+          strcpy(reply, "OK");
+        } else {
+          strcpy(reply, "Err - invalid params");
+        }
+      } else {
+        strcpy(reply, "Err - bad pubkey");
+      }
+    }
+  } else if (sender_timestamp == 0 && strcmp(command, "get acl") == 0) {
+    Serial.println("ACL:");
+    for (int i = 0; i < acl.getNumClients(); i++) {
+      auto c = acl.getClientByIdx(i);
+      if (c->permissions == 0) continue;  // skip deleted (or guest) entries
+
+      Serial.printf("%02X ", c->permissions);
+      mesh::Utils::printHex(Serial, c->id.pub_key, PUB_KEY_SIZE);
+      Serial.printf("\n");
+    }
+    reply[0] = 0;
+  } else{
+    _cli.handleCommand(sender_timestamp, command, reply);  // common CLI commands
+  }
 }

 void MyMesh::loop() {
@@ -698,4 +742,10 @@ void MyMesh::loop() {
    radio_set_params(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
    MESH_DEBUG_PRINTLN("Radio params restored");
  }
+
+  // is pending dirty contacts write needed?
+  if (dirty_contacts_expiry && millisHasNowPassed(dirty_contacts_expiry)) {
+    acl.save(_fs);
+    dirty_contacts_expiry = 0;
+  }
 }
--- a/examples/simple_repeater/MyMesh.h
+++ b/examples/simple_repeater/MyMesh.h
@@ -18,6 +18,7 @@
 #include <helpers/IdentityStore.h>
 #include <helpers/AdvertDataHelpers.h>
 #include <helpers/TxtDataHelpers.h>
+#include <helpers/ClientACL.h>
 #include <RTClib.h>
 #include <target.h>

@@ -52,15 +53,6 @@ struct RepeaterStats {
  uint32_t total_rx_air_time_secs;
 };

-struct ClientInfo {
-  mesh::Identity id;
-  uint32_t last_timestamp, last_activity;
-  uint8_t secret[PUB_KEY_SIZE];
-  bool    is_admin;
-  int8_t  out_path_len;
-  uint8_t out_path[MAX_PATH_SIZE];
-};
-
 #ifndef MAX_CLIENTS
  #define MAX_CLIENTS           32
 #endif
@@ -91,7 +83,8 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
  NodePrefs _prefs;
  CommonCLI _cli;
  uint8_t reply_data[MAX_PACKET_PAYLOAD];
-  ClientInfo known_clients[MAX_CLIENTS];
+  ClientACL  acl;
+  unsigned long dirty_contacts_expiry;
 #if MAX_NEIGHBOURS
  NeighbourInfo neighbours[MAX_NEIGHBOURS];
 #endif
@@ -108,8 +101,8 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
  ESPNowBridge bridge;
 #endif

-  ClientInfo* putClient(const mesh::Identity& id);
  void putNeighbour(const mesh::Identity& id, uint32_t timestamp, float snr);
+  uint8_t handleLoginReq(const mesh::Identity& sender, const uint8_t* secret, uint32_t sender_timestamp, const uint8_t* data);
  int handleRequest(ClientInfo* sender, uint32_t sender_timestamp, uint8_t* payload, size_t payload_len);
  mesh::Packet* createSelfAdvert();

--- a/examples/simple_room_server/MyMesh.cpp
+++ b/examples/simple_room_server/MyMesh.cpp
@@ -15,9 +15,12 @@
 #define REQ_TYPE_GET_STATUS         0x01 // same as _GET_STATS
 #define REQ_TYPE_KEEP_ALIVE         0x02
 #define REQ_TYPE_GET_TELEMETRY_DATA 0x03
+#define REQ_TYPE_GET_ACCESS_LIST    0x05

 #define RESP_SERVER_LOGIN_OK        0 // response to ANON_REQ

+#define LAZY_CONTACTS_WRITE_DELAY    5000
+
 struct ServerStats {
  uint16_t batt_milli_volts;
  uint16_t curr_tx_queue_len;
@@ -35,38 +38,6 @@ struct ServerStats {
  uint16_t n_posted, n_post_push;
 };

-ClientInfo *MyMesh::putClient(const mesh::Identity &id) {
-  for (int i = 0; i < num_clients; i++) {
-    if (id.matches(known_clients[i].id)) return &known_clients[i]; // already known
-  }
-  ClientInfo *newClient;
-  if (num_clients < MAX_CLIENTS) {
-    newClient = &known_clients[num_clients++];
-  } else { // table is currently full
-    // evict least active client
-    uint32_t oldest_timestamp = 0xFFFFFFFF;
-    newClient = &known_clients[0];
-    for (int i = 0; i < num_clients; i++) {
-      auto c = &known_clients[i];
-      if (c->last_activity < oldest_timestamp) {
-        oldest_timestamp = c->last_activity;
-        newClient = c;
-      }
-    }
-  }
-  newClient->id = id;
-  newClient->out_path_len = -1; // initially out_path is unknown
-  newClient->last_timestamp = 0;
-  return newClient;
-}
-
-void MyMesh::evict(ClientInfo *client) {
-  client->last_activity = 0; // this slot will now be re-used (will be oldest)
-  memset(client->id.pub_key, 0, sizeof(client->id.pub_key));
-  memset(client->secret, 0, sizeof(client->secret));
-  client->pending_ack = 0;
-}
-
 void MyMesh::addPost(ClientInfo *client, const char *postData) {
  // TODO: suggested postData format: <title>/<descrption>
  posts[next_post_idx].author = client->id; // add to cyclic queue
@@ -97,22 +68,22 @@ void MyMesh::pushPostToClient(ClientInfo *client, PostInfo &post) {
  len += text_len;

  // calc expected ACK reply
-  mesh::Utils::sha256((uint8_t *)&client->pending_ack, 4, reply_data, len, client->id.pub_key, PUB_KEY_SIZE);
-  client->push_post_timestamp = post.post_timestamp;
+  mesh::Utils::sha256((uint8_t *)&client->extra.room.pending_ack, 4, reply_data, len, client->id.pub_key, PUB_KEY_SIZE);
+  client->extra.room.push_post_timestamp = post.post_timestamp;

-  auto reply = createDatagram(PAYLOAD_TYPE_TXT_MSG, client->id, client->secret, reply_data, len);
+  auto reply = createDatagram(PAYLOAD_TYPE_TXT_MSG, client->id, client->shared_secret, reply_data, len);
  if (reply) {
    if (client->out_path_len < 0) {
      sendFlood(reply);
-      client->ack_timeout = futureMillis(PUSH_ACK_TIMEOUT_FLOOD);
+      client->extra.room.ack_timeout = futureMillis(PUSH_ACK_TIMEOUT_FLOOD);
    } else {
      sendDirect(reply, client->out_path, client->out_path_len);
-      client->ack_timeout =
+      client->extra.room.ack_timeout =
          futureMillis(PUSH_TIMEOUT_BASE + PUSH_ACK_TIMEOUT_FACTOR * (client->out_path_len + 1));
    }
    _num_post_pushes++; // stats
  } else {
-    client->pending_ack = 0;
+    client->extra.room.pending_ack = 0;
    MESH_DEBUG_PRINTLN("Unable to push post to client");
  }
 }
@@ -120,7 +91,7 @@ void MyMesh::pushPostToClient(ClientInfo *client, PostInfo &post) {
 uint8_t MyMesh::getUnsyncedCount(ClientInfo *client) {
  uint8_t count = 0;
  for (int k = 0; k < MAX_UNSYNCED_POSTS; k++) {
-    if (posts[k].post_timestamp > client->sync_since // is new post for this Client?
+    if (posts[k].post_timestamp > client->extra.room.sync_since // is new post for this Client?
        && !posts[k].author.matches(client->id)) {   // don't push posts to the author
      count++;
    }
@@ -129,12 +100,12 @@ uint8_t MyMesh::getUnsyncedCount(ClientInfo *client) {
 }

 bool MyMesh::processAck(const uint8_t *data) {
-  for (int i = 0; i < num_clients; i++) {
-    auto client = &known_clients[i];
-    if (client->pending_ack && memcmp(data, &client->pending_ack, 4) == 0) { // got an ACK from Client!
-      client->pending_ack = 0; // clear this, so next push can happen
-      client->push_failures = 0;
-      client->sync_since = client->push_post_timestamp; // advance Client's SINCE timestamp, to sync next post
+  for (int i = 0; i < acl.getNumClients(); i++) {
+    auto client = acl.getClientByIdx(i);
+    if (client->extra.room.pending_ack && memcmp(data, &client->extra.room.pending_ack, 4) == 0) { // got an ACK from Client!
+      client->extra.room.pending_ack = 0; // clear this, so next push can happen
+      client->extra.room.push_failures = 0;
+      client->extra.room.sync_since = client->extra.room.push_post_timestamp; // advance Client's SINCE timestamp, to sync next post
      return true;
    }
  }
@@ -168,8 +139,7 @@ int MyMesh::handleRequest(ClientInfo *sender, uint32_t sender_timestamp, uint8_t
  // memcpy(reply_data, &now, 4);   // response packets always prefixed with timestamp
  memcpy(reply_data, &sender_timestamp, 4); // reflect sender_timestamp back in response packet (kind of like a 'tag')

-  switch (payload[0]) {
-  case REQ_TYPE_GET_STATUS: {
+  if (payload[0] == REQ_TYPE_GET_STATUS) {
    ServerStats stats;
    stats.batt_milli_volts = board.getBattMilliVolts();
    stats.curr_tx_queue_len = _mgr->getOutboundCount(0xFFFFFFFF);
@@ -193,19 +163,31 @@ int MyMesh::handleRequest(ClientInfo *sender, uint32_t sender_timestamp, uint8_t
    memcpy(&reply_data[4], &stats, sizeof(stats));
    return 4 + sizeof(stats);
  }
-
-  case REQ_TYPE_GET_TELEMETRY_DATA: {
+  if (payload[0] == REQ_TYPE_GET_TELEMETRY_DATA) {
    uint8_t perm_mask = ~(payload[1]); // NEW: first reserved byte (of 4), is now inverse mask to apply to permissions

    telemetry.reset();
    telemetry.addVoltage(TELEM_CHANNEL_SELF, (float)board.getBattMilliVolts() / 1000.0f);
    // query other sensors -- target specific
-    sensors.querySensors((sender->permission == RoomPermission::ADMIN ? 0xFF : 0x00) & perm_mask, telemetry);
+    sensors.querySensors((sender->isAdmin() ? 0xFF : 0x00) & perm_mask, telemetry);

    uint8_t tlen = telemetry.getSize();
    memcpy(&reply_data[4], telemetry.getBuffer(), tlen);
    return 4 + tlen; // reply_len
  }
+  if (payload[0] == REQ_TYPE_GET_ACCESS_LIST && sender->isAdmin()) {
+    uint8_t res1 = payload[1];   // reserved for future  (extra query params)
+    uint8_t res2 = payload[2];
+    if (res1 == 0 && res2 == 0) {
+      uint8_t ofs = 4;
+      for (int i = 0; i < acl.getNumClients() && ofs + 7 <= sizeof(reply_data) - 4; i++) {
+        auto c = acl.getClientByIdx(i);
+        if (!c->isAdmin()) continue;  // skip non-Admin entries
+        memcpy(&reply_data[ofs], c->id.pub_key, 6); ofs += 6;  // just 6-byte pub_key prefix
+        reply_data[ofs++] = c->permissions;
+      }
+      return ofs;
+    }
  }
  return 0; // unknown command
 }
@@ -305,56 +287,71 @@ void MyMesh::onAnonDataRecv(mesh::Packet *packet, const uint8_t *secret, const m
    memcpy(&sender_timestamp, data, 4);
    memcpy(&sender_sync_since, &data[4], 4); // sender's "sync messags SINCE x" timestamp

-    RoomPermission perm;
    data[len] = 0;                                        // ensure null terminator
-    if (strcmp((char *)&data[8], _prefs.password) == 0) { // check for valid admin password
-      perm = RoomPermission::ADMIN;
-    } else {
-      if (strcmp((char *)&data[8], _prefs.guest_password) == 0) { // check the room/public password
-        perm = RoomPermission::GUEST;
-      } else if (_prefs.allow_read_only) {
-        perm = RoomPermission::READ_ONLY;
-      } else {
-        MESH_DEBUG_PRINTLN("Incorrect room password");
-        return; // no response. Client will timeout
+
+    ClientInfo* client;
+    if (data[8] == 0 && !_prefs.allow_read_only) {   // blank password, just check if sender is in ACL
+      client = acl.getClient(sender.pub_key, PUB_KEY_SIZE);
+      if (client == NULL) {
+      #if MESH_DEBUG
+        MESH_DEBUG_PRINTLN("Login, sender not in ACL");
+      #endif
+        return;
      }
+    } else {
+      uint8_t perm;
+      if (strcmp((char *)&data[8], _prefs.password) == 0) { // check for valid admin password
+        perm = PERM_ACL_ADMIN;
+      } else {
+        if (strcmp((char *)&data[8], _prefs.guest_password) == 0) {   // check the room/public password
+          perm = PERM_ACL_READ_WRITE;
+        } else if (_prefs.allow_read_only) {
+          perm = PERM_ACL_GUEST;
+        } else {
+          MESH_DEBUG_PRINTLN("Incorrect room password");
+          return; // no response. Client will timeout
+        }
+      }
+
+      client = acl.putClient(sender, 0);  // add to known clients (if not already known)
+      if (sender_timestamp <= client->last_timestamp) {
+        MESH_DEBUG_PRINTLN("possible replay attack!");
+        return;
+      }
+
+      MESH_DEBUG_PRINTLN("Login success!");
+      client->last_timestamp = sender_timestamp;
+      client->extra.room.sync_since = sender_sync_since;
+      client->extra.room.pending_ack = 0;
+      client->extra.room.push_failures = 0;
+
+      client->last_activity = getRTCClock()->getCurrentTime();
+      client->permissions |= perm;
+      memcpy(client->shared_secret, secret, PUB_KEY_SIZE);
+
+      dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);
    }

-    auto client = putClient(sender); // add to known clients (if not already known)
-    if (sender_timestamp <= client->last_timestamp) {
-      MESH_DEBUG_PRINTLN("possible replay attack!");
-      return;
-    }
-
-    MESH_DEBUG_PRINTLN("Login success!");
-    client->permission = perm;
-    client->last_timestamp = sender_timestamp;
-    client->sync_since = sender_sync_since;
-    client->pending_ack = 0;
-    client->push_failures = 0;
-    memcpy(client->secret, secret, PUB_KEY_SIZE);
-
-    uint32_t now = getRTCClock()->getCurrentTime();
-    client->last_activity = now;
-
-    now = getRTCClock()->getCurrentTimeUnique();
+    uint32_t now = getRTCClock()->getCurrentTimeUnique();
    memcpy(reply_data, &now, 4); // response packets always prefixed with timestamp
    // TODO: maybe reply with count of messages waiting to be synced for THIS client?
    reply_data[4] = RESP_SERVER_LOGIN_OK;
    reply_data[5] = (CLIENT_KEEP_ALIVE_SECS >> 4); // NEW: recommended keep-alive interval (secs / 16)
-    reply_data[6] = (perm == RoomPermission::ADMIN ? 1 : (perm == RoomPermission::GUEST ? 0 : 2));
-    reply_data[7] = getUnsyncedCount(client); // NEW
-    memcpy(&reply_data[8], "OK", 2);          // REVISIT: not really needed
+    reply_data[6] = (client->isAdmin() ? 1 : (client->permissions == 0 ? 2 : 0));
+    // LEGACY: reply_data[7] = getUnsyncedCount(client);
+    reply_data[7] = client->permissions; // NEW
+    getRNG()->random(&reply_data[8], 4);   // random blob to help packet-hash uniqueness
+    // LEGACY: memcpy(&reply_data[8], "OK", 2);

    next_push = futureMillis(PUSH_NOTIFY_DELAY_MILLIS); // delay next push, give RESPONSE packet time to arrive first

    if (packet->isRouteFlood()) {
      // let this sender know path TO here, so they can use sendDirect(), and ALSO encode the response
-      mesh::Packet *path = createPathReturn(sender, client->secret, packet->path, packet->path_len,
-                                            PAYLOAD_TYPE_RESPONSE, reply_data, 8 + 2);
+      mesh::Packet *path = createPathReturn(sender, client->shared_secret, packet->path, packet->path_len,
+                                            PAYLOAD_TYPE_RESPONSE, reply_data, 12);
      if (path) sendFlood(path, SERVER_RESPONSE_DELAY);
    } else {
-      mesh::Packet *reply = createDatagram(PAYLOAD_TYPE_RESPONSE, sender, client->secret, reply_data, 8 + 2);
+      mesh::Packet *reply = createDatagram(PAYLOAD_TYPE_RESPONSE, sender, client->shared_secret, reply_data, 12);
      if (reply) {
        if (client->out_path_len >= 0) { // we have an out_path, so send DIRECT
          sendDirect(reply, client->out_path, client->out_path_len, SERVER_RESPONSE_DELAY);
@@ -368,8 +365,8 @@ void MyMesh::onAnonDataRecv(mesh::Packet *packet, const uint8_t *secret, const m

 int MyMesh::searchPeersByHash(const uint8_t *hash) {
  int n = 0;
-  for (int i = 0; i < num_clients; i++) {
-    if (known_clients[i].id.isHashMatch(hash)) {
+  for (int i = 0; i < acl.getNumClients(); i++) {
+    if (acl.getClientByIdx(i)->id.isHashMatch(hash)) {
      matching_peer_indexes[n++] = i; // store the INDEXES of matching contacts (for subsequent 'peer' methods)
    }
  }
@@ -378,9 +375,9 @@ int MyMesh::searchPeersByHash(const uint8_t *hash) {

 void MyMesh::getPeerSharedSecret(uint8_t *dest_secret, int peer_idx) {
  int i = matching_peer_indexes[peer_idx];
-  if (i >= 0 && i < num_clients) {
+  if (i >= 0 && i < acl.getNumClients()) {
    // lookup pre-calculated shared_secret
-    memcpy(dest_secret, known_clients[i].secret, PUB_KEY_SIZE);
+    memcpy(dest_secret, acl.getClientByIdx(i)->shared_secret, PUB_KEY_SIZE);
  } else {
    MESH_DEBUG_PRINTLN("getPeerSharedSecret: Invalid peer idx: %d", i);
  }
@@ -389,11 +386,11 @@ void MyMesh::getPeerSharedSecret(uint8_t *dest_secret, int peer_idx) {
 void MyMesh::onPeerDataRecv(mesh::Packet *packet, uint8_t type, int sender_idx, const uint8_t *secret,
                            uint8_t *data, size_t len) {
  int i = matching_peer_indexes[sender_idx];
-  if (i < 0 || i >= num_clients) { // get from our known_clients table (sender SHOULD already be known in this context)
+  if (i < 0 || i >= acl.getNumClients()) { // get from our known_clients table (sender SHOULD already be known in this context)
    MESH_DEBUG_PRINTLN("onPeerDataRecv: invalid peer idx: %d", i);
    return;
  }
-  auto client = &known_clients[i];
+  auto client = acl.getClientByIdx(i);
  if (type == PAYLOAD_TYPE_TXT_MSG && len > 5) { // a CLI command or new Post
    uint32_t sender_timestamp;
    memcpy(&sender_timestamp, data, 4); // timestamp (by sender's RTC clock - which could be wrong)
@@ -407,7 +404,7 @@ void MyMesh::onPeerDataRecv(mesh::Packet *packet, uint8_t type, int sender_idx,

      uint32_t now = getRTCClock()->getCurrentTimeUnique();
      client->last_activity = now;
-      client->push_failures = 0; // reset so push can resume (if prev failed)
+      client->extra.room.push_failures = 0; // reset so push can resume (if prev failed)

      // len can be > original length, but 'text' will be padded with zeroes
      data[len] = 0; // need to make a C string again, with null terminator
@@ -420,7 +417,7 @@ void MyMesh::onPeerDataRecv(mesh::Packet *packet, uint8_t type, int sender_idx,
      uint8_t temp[166];
      bool send_ack;
      if (flags == TXT_TYPE_CLI_DATA) {
-        if (client->permission == RoomPermission::ADMIN) {
+        if (client->isAdmin()) {
          if (is_retry) {
            temp[5] = 0; // no reply
          } else {
@@ -433,7 +430,7 @@ void MyMesh::onPeerDataRecv(mesh::Packet *packet, uint8_t type, int sender_idx,
          send_ack = false; // and no ACK...  user shoudn't be sending these
        }
      } else { // TXT_TYPE_PLAIN
-        if (client->permission == RoomPermission::READ_ONLY) {
+        if ((client->permissions & PERM_ACL_ROLE_MASK) == PERM_ACL_GUEST) {
          temp[5] = 0;      // no reply
          send_ack = false; // no ACK
        } else {
@@ -501,7 +498,7 @@ void MyMesh::onPeerDataRecv(mesh::Packet *packet, uint8_t type, int sender_idx,

      uint32_t now = getRTCClock()->getCurrentTime();
      client->last_activity = now; // <-- THIS will keep client connection alive
-      client->push_failures = 0;   // reset so push can resume (if prev failed)
+      client->extra.room.push_failures = 0;   // reset so push can resume (if prev failed)

      if (data[4] == REQ_TYPE_KEEP_ALIVE && packet->isRouteDirect()) { // request type
        uint32_t forceSince = 0;
@@ -511,10 +508,10 @@ void MyMesh::onPeerDataRecv(mesh::Packet *packet, uint8_t type, int sender_idx,
          memcpy(&data[5], &forceSince, 4); // make sure there are zeroes in payload (for ack_hash calc below)
        }
        if (forceSince > 0) {
-          client->sync_since = forceSince; // force-update the 'sync since'
+          client->extra.room.sync_since = forceSince; // force-update the 'sync since'
        }

-        client->pending_ack = 0;
+        client->extra.room.pending_ack = 0;

        // TODO: Throttle KEEP_ALIVE requests!
        // if client sends too quickly, evict()
@@ -559,10 +556,11 @@ bool MyMesh::onPeerPathRecv(mesh::Packet *packet, int sender_idx, const uint8_t
  // TODO: prevent replay attacks
  int i = matching_peer_indexes[sender_idx];

-  if (i >= 0 && i < num_clients) { // get from our known_clients table (sender SHOULD already be known in this context)
+  if (i >= 0 && i < acl.getNumClients()) { // get from our known_clients table (sender SHOULD already be known in this context)
    MESH_DEBUG_PRINTLN("PATH to client, path_len=%d", (uint32_t)path_len);
-    auto client = &known_clients[i];
+    auto client = acl.getClientByIdx(i);
    memcpy(client->out_path, path, client->out_path_len = path_len); // store a copy of path, for sendDirect()
+    client->last_activity = getRTCClock()->getCurrentTime();
  } else {
    MESH_DEBUG_PRINTLN("onPeerPathRecv: invalid peer idx: %d", i);
  }
@@ -587,6 +585,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
    : mesh::Mesh(radio, ms, rng, rtc, *new StaticPoolPacketManager(32), tables),
      _cli(board, rtc, &_prefs, this), telemetry(MAX_PACKET_PAYLOAD - 4) {
  next_local_advert = next_flood_advert = 0;
+  dirty_contacts_expiry = 0;
  _logging = false;
  set_radio_at = revert_radio_at = 0;

@@ -613,7 +612,6 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
  StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
 #endif

-  num_clients = 0;
  next_post_idx = 0;
  next_client_idx = 0;
  next_push = 0;
@@ -627,6 +625,8 @@ void MyMesh::begin(FILESYSTEM *fs) {
  // load persisted prefs
  _cli.loadPrefs(_fs);

+  acl.load(_fs);
+
  radio_set_params(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
  radio_set_tx_power(_prefs.tx_power_dbm);

@@ -731,33 +731,73 @@ void MyMesh::handleCommand(uint32_t sender_timestamp, char *command, char *reply
    command += 3;
  }

-  _cli.handleCommand(sender_timestamp, command, reply); // common CLI commands
+  // handle ACL related commands
+  if (memcmp(command, "setperm ", 8) == 0) {   // format:  setperm {pubkey-hex} {permissions-int8}
+    char* hex = &command[8];
+    char* sp = strchr(hex, ' ');   // look for separator char
+    if (sp == NULL) {
+      strcpy(reply, "Err - bad params");
+    } else {
+      *sp++ = 0;   // replace space with null terminator
+
+      uint8_t pubkey[PUB_KEY_SIZE];
+      int hex_len = min(sp - hex, PUB_KEY_SIZE*2);
+      if (mesh::Utils::fromHex(pubkey, hex_len / 2, hex)) {
+        uint8_t perms = atoi(sp);
+        if (acl.applyPermissions(self_id, pubkey, hex_len / 2, perms)) {
+          dirty_contacts_expiry = futureMillis(LAZY_CONTACTS_WRITE_DELAY);   // trigger acl.save()
+          strcpy(reply, "OK");
+        } else {
+          strcpy(reply, "Err - invalid params");
+        }
+      } else {
+        strcpy(reply, "Err - bad pubkey");
+      }
+    }
+  } else if (sender_timestamp == 0 && strcmp(command, "get acl") == 0) {
+    Serial.println("ACL:");
+    for (int i = 0; i < acl.getNumClients(); i++) {
+      auto c = acl.getClientByIdx(i);
+      if (c->permissions == 0) continue;  // skip deleted (or guest) entries
+
+      Serial.printf("%02X ", c->permissions);
+      mesh::Utils::printHex(Serial, c->id.pub_key, PUB_KEY_SIZE);
+      Serial.printf("\n");
+    }
+    reply[0] = 0;
+  } else{
+    _cli.handleCommand(sender_timestamp, command, reply);  // common CLI commands
+  }
+}
+
+bool MyMesh::saveFilter(ClientInfo* client) {
+  return client->isAdmin();    // only save Admins
 }

 void MyMesh::loop() {
  mesh::Mesh::loop();

-  if (millisHasNowPassed(next_push) && num_clients > 0) {
+  if (millisHasNowPassed(next_push) && acl.getNumClients() > 0) {
    // check for ACK timeouts
-    for (int i = 0; i < num_clients; i++) {
-      auto c = &known_clients[i];
-      if (c->pending_ack && millisHasNowPassed(c->ack_timeout)) {
-        c->push_failures++;
-        c->pending_ack = 0; // reset  (TODO: keep prev expected_ack's in a list, incase they arrive LATER, after we retry)
+    for (int i = 0; i < acl.getNumClients(); i++) {
+      auto c = acl.getClientByIdx(i);
+      if (c->extra.room.pending_ack && millisHasNowPassed(c->extra.room.ack_timeout)) {
+        c->extra.room.push_failures++;
+        c->extra.room.pending_ack = 0; // reset  (TODO: keep prev expected_ack's in a list, incase they arrive LATER, after we retry)
        MESH_DEBUG_PRINTLN("pending ACK timed out: push_failures: %d", (uint32_t)c->push_failures);
      }
    }
    // check next Round-Robin client, and sync next new post
-    auto client = &known_clients[next_client_idx];
+    auto client = acl.getClientByIdx(next_client_idx);
    bool did_push = false;
-    if (client->pending_ack == 0 && client->last_activity != 0 &&
-        client->push_failures < 3) { // not already waiting for ACK, AND not evicted, AND retries not max
+    if (client->extra.room.pending_ack == 0 && client->last_activity != 0 &&
+        client->extra.room.push_failures < 3) { // not already waiting for ACK, AND not evicted, AND retries not max
      MESH_DEBUG_PRINTLN("loop - checking for client %02X", (uint32_t)client->id.pub_key[0]);
      uint32_t now = getRTCClock()->getCurrentTime();
      for (int k = 0, idx = next_post_idx; k < MAX_UNSYNCED_POSTS; k++) {
        auto p = &posts[idx];
        if (now >= p->post_timestamp + POST_SYNC_DELAY_SECS &&
-            p->post_timestamp > client->sync_since // is new post for this Client?
+            p->post_timestamp > client->extra.room.sync_since // is new post for this Client?
            && !p->author.matches(client->id)) {   // don't push posts to the author
          // push this post to Client, then wait for ACK
          pushPostToClient(client, *p);
@@ -770,7 +810,7 @@ void MyMesh::loop() {
    } else {
      MESH_DEBUG_PRINTLN("loop - skipping busy (or evicted) client %02X", (uint32_t)client->id.pub_key[0]);
    }
-    next_client_idx = (next_client_idx + 1) % num_clients; // round robin polling for each client
+    next_client_idx = (next_client_idx + 1) % acl.getNumClients(); // round robin polling for each client

    if (did_push) {
      next_push = futureMillis(SYNC_PUSH_INTERVAL);
@@ -805,5 +845,11 @@ void MyMesh::loop() {
    MESH_DEBUG_PRINTLN("Radio params restored");
  }

+  // is pending dirty contacts write needed?
+  if (dirty_contacts_expiry && millisHasNowPassed(dirty_contacts_expiry)) {
+    acl.save(_fs, MyMesh::saveFilter);
+    dirty_contacts_expiry = 0;
+  }
+
  // TODO: periodically check for OLD/inactive entries in known_clients[], and evict
 }
--- a/examples/simple_room_server/MyMesh.h
+++ b/examples/simple_room_server/MyMesh.h
@@ -18,6 +18,7 @@
 #include <helpers/AdvertDataHelpers.h>
 #include <helpers/TxtDataHelpers.h>
 #include <helpers/CommonCLI.h>
+#include <helpers/ClientACL.h>
 #include <RTClib.h>
 #include <target.h>

@@ -61,10 +62,6 @@
  #define  ADMIN_PASSWORD  "password"
 #endif

-#ifndef MAX_CLIENTS
- #define MAX_CLIENTS           32
-#endif
-
 #ifndef MAX_UNSYNCED_POSTS
  #define MAX_UNSYNCED_POSTS    32
 #endif
@@ -81,27 +78,6 @@

 #define PACKET_LOG_FILE  "/packet_log"

-enum RoomPermission {
-  ADMIN,
-  GUEST,
-  READ_ONLY
-};
-
-struct ClientInfo {
-  mesh::Identity id;
-  uint32_t last_timestamp;  // by THEIR clock
-  uint32_t last_activity;   // by OUR clock
-  uint32_t sync_since;  // sync messages SINCE this timestamp (by OUR clock)
-  uint32_t pending_ack;
-  uint32_t push_post_timestamp;
-  unsigned long ack_timeout;
-  RoomPermission  permission;
-  uint8_t  push_failures;
-  uint8_t  secret[PUB_KEY_SIZE];
-  int      out_path_len;
-  uint8_t  out_path[MAX_PATH_SIZE];
-};
-
 #define MAX_POST_TEXT_LEN    (160-9)

 struct PostInfo {
@@ -116,9 +92,9 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
  bool _logging;
  NodePrefs _prefs;
  CommonCLI _cli;
+  ClientACL acl;
+  unsigned long dirty_contacts_expiry;
  uint8_t reply_data[MAX_PACKET_PAYLOAD];
-  int num_clients;
-  ClientInfo known_clients[MAX_CLIENTS];
  unsigned long next_push;
  uint16_t _num_posted, _num_post_pushes;
  int next_client_idx;  // for round-robin polling
@@ -132,8 +108,6 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {
  uint8_t pending_cr;
  int  matching_peer_indexes[MAX_CLIENTS];

-  ClientInfo* putClient(const mesh::Identity& id);
-  void  evict(ClientInfo* client);
  void addPost(ClientInfo* client, const char* postData);
  void pushPostToClient(ClientInfo* client, PostInfo& post);
  uint8_t getUnsyncedCount(ClientInfo* client);
@@ -213,6 +187,8 @@ public:

  mesh::LocalIdentity& getSelfId() override { return self_id; }

+  static bool saveFilter(ClientInfo* client);
+
  void saveIdentity(const mesh::LocalIdentity& new_id) override;
  void clearStats() override;
  void handleCommand(uint32_t sender_timestamp, char* command, char* reply);
--- a/examples/simple_secure_chat/main.cpp
+++ b/examples/simple_secure_chat/main.cpp
@@ -217,18 +217,18 @@ protected:
    saveContacts();
  }

-  bool processAck(const uint8_t *data) override {
+  ContactInfo* processAck(const uint8_t *data) override {
    if (memcmp(data, &expected_ack_crc, 4) == 0) {     // got an ACK from recipient
      Serial.printf("   Got ACK! (round trip: %d millis)\n", _ms->getMillis() - last_msg_sent);
      // NOTE: the same ACK can be received multiple times!
      expected_ack_crc = 0;  // reset our expected hash, now that we have received ACK
-      return true;
+      return NULL;  // TODO: really should return ContactInfo pointer 
    }

    //uint32_t crc;
    //memcpy(&crc, data, 4);
    //MESH_DEBUG_PRINTLN("unknown ACK received: %08X (expected: %08X)", crc, expected_ack_crc);
-    return false;
+    return NULL;
  }

  void onMessageRecv(const ContactInfo& from, mesh::Packet* pkt, uint32_t sender_timestamp, const char *text) override {
--- a/platformio.ini
+++ b/platformio.ini
@@ -107,6 +107,7 @@ build_src_filter = ${arduino_base.build_src_filter}
  +<helpers/stm32>
 lib_deps = ${arduino_base.lib_deps}
  file://arch/stm32/Adafruit_LittleFS_stm32
+  adafruit/Adafruit BusIO @ 1.17.2

 [sensor_base]
 build_flags =
--- a/src/helpers/BaseChatMesh.cpp
+++ b/src/helpers/BaseChatMesh.cpp
@@ -158,6 +158,7 @@ void BaseChatMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender
    data[len] = 0; // need to make a C string again, with null terminator

    if (flags == TXT_TYPE_PLAIN) {
+      from.lastmod = getRTCClock()->getCurrentTime(); // update last heard time
      onMessageRecv(from, packet, timestamp, (const char *) &data[5]);  // let UI know

      uint32_t ack_hash;    // calc truncated hash of the message timestamp + text + sender pub_key, to prove to sender that we got it
@@ -184,6 +185,7 @@ void BaseChatMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender
      if (timestamp > from.sync_since) {  // make sure 'sync_since' is up-to-date
        from.sync_since = timestamp;
      }
+      from.lastmod = getRTCClock()->getCurrentTime(); // update last heard time
      onSignedMessageRecv(from, packet, timestamp, &data[5], (const char *) &data[9]);  // let UI know

      uint32_t ack_hash;    // calc truncated hash of the message timestamp + text + OUR pub_key, to prove to sender that we got it
@@ -223,6 +225,10 @@ void BaseChatMesh::onPeerDataRecv(mesh::Packet* packet, uint8_t type, int sender
    }
  } else if (type == PAYLOAD_TYPE_RESPONSE && len > 0) {
    onContactResponse(from, data, len);
+    if (packet->isRouteFlood() && from.out_path_len >= 0) {
+      // we have direct path, but other node is still sending flood response, so maybe they didn't receive reciprocal path properly(?)
+      handleReturnPathRetry(from, packet->path, packet->path_len);
+    }
  }
 }

@@ -248,7 +254,7 @@ bool BaseChatMesh::onContactPathRecv(ContactInfo& from, uint8_t* in_path, uint8_

  if (extra_type == PAYLOAD_TYPE_ACK && extra_len >= 4) {
    // also got an encoded ACK!
-    if (processAck(extra)) {
+    if (processAck(extra) != NULL) {
      txt_send_timeout = 0;   // matched one we're waiting for, cancel timeout timer
    }
  } else if (extra_type == PAYLOAD_TYPE_RESPONSE && extra_len > 0) {
@@ -258,12 +264,25 @@ bool BaseChatMesh::onContactPathRecv(ContactInfo& from, uint8_t* in_path, uint8_
 }

 void BaseChatMesh::onAckRecv(mesh::Packet* packet, uint32_t ack_crc) {
-  if (processAck((uint8_t *)&ack_crc)) {
+  ContactInfo* from;
+  if ((from = processAck((uint8_t *)&ack_crc)) != NULL) {
    txt_send_timeout = 0;   // matched one we're waiting for, cancel timeout timer
    packet->markDoNotRetransmit();   // ACK was for this node, so don't retransmit
+
+    if (packet->isRouteFlood() && from->out_path_len >= 0) {
+      // we have direct path, but other node is still sending flood, so maybe they didn't receive reciprocal path properly(?)
+      handleReturnPathRetry(*from, packet->path, packet->path_len);
+    }
  }
 }

+void BaseChatMesh::handleReturnPathRetry(const ContactInfo& contact, const uint8_t* path, uint8_t path_len) {
+  // NOTE: simplest impl is just to re-send a reciprocal return path to sender (DIRECTLY)
+  //        override this method in various firmwares, if there's a better strategy
+  mesh::Packet* rpath = createPathReturn(contact.id, contact.shared_secret, path, path_len, 0, NULL, 0);
+  if (rpath) sendDirect(rpath, contact.out_path, contact.out_path_len, 3000);   // 3 second delay
+}
+
 #ifdef MAX_GROUP_CHANNELS
 int BaseChatMesh::searchChannelsByHash(const uint8_t* hash, mesh::GroupChannel dest[], int max_matches) {
  int n = 0;
@@ -550,7 +569,7 @@ void BaseChatMesh::markConnectionActive(const ContactInfo& contact) {
  }
 }

-bool BaseChatMesh::checkConnectionsAck(const uint8_t* data) {
+ContactInfo* BaseChatMesh::checkConnectionsAck(const uint8_t* data) {
  for (int i = 0; i < MAX_CONNECTIONS; i++) {
    if (connections[i].keep_alive_millis > 0 && memcmp(&connections[i].expected_ack, data, 4) == 0) {
      // yes, got an ack for our keep_alive request!
@@ -559,10 +578,12 @@ bool BaseChatMesh::checkConnectionsAck(const uint8_t* data) {

      // re-schedule next KEEP_ALIVE, now that we have heard from server
      connections[i].next_ping = futureMillis(connections[i].keep_alive_millis);
-      return true;  // yes, a match
+
+      auto id = &connections[i].server_id;
+      return lookupContactByPubKey(id->pub_key, PUB_KEY_SIZE);  // yes, a match
    }
  }
-  return false;  /// no match
+  return NULL;  /// no match
 }

 void BaseChatMesh::checkConnections() {
--- a/src/helpers/BaseChatMesh.h
+++ b/src/helpers/BaseChatMesh.h
@@ -93,7 +93,7 @@ protected:
  // 'UI' concepts, for sub-classes to implement
  virtual bool isAutoAddEnabled() const { return true; }
  virtual void onDiscoveredContact(ContactInfo& contact, bool is_new, uint8_t path_len, const uint8_t* path) = 0;
-  virtual bool processAck(const uint8_t *data) = 0;
+  virtual ContactInfo* processAck(const uint8_t *data) = 0;
  virtual void onContactPathUpdated(const ContactInfo& contact) = 0;
  virtual bool onContactPathRecv(ContactInfo& from, uint8_t* in_path, uint8_t in_path_len, uint8_t* out_path, uint8_t out_path_len, uint8_t extra_type, uint8_t* extra, uint8_t extra_len);
  virtual void onMessageRecv(const ContactInfo& contact, mesh::Packet* pkt, uint32_t sender_timestamp, const char *text) = 0;
@@ -105,6 +105,7 @@ protected:
  virtual void onChannelMessageRecv(const mesh::GroupChannel& channel, mesh::Packet* pkt, uint32_t timestamp, const char *text) = 0;
  virtual uint8_t onContactRequest(const ContactInfo& contact, uint32_t sender_timestamp, const uint8_t* data, uint8_t len, uint8_t* reply) = 0;
  virtual void onContactResponse(const ContactInfo& contact, const uint8_t* data, uint8_t len) = 0;
+  virtual void handleReturnPathRetry(const ContactInfo& contact, const uint8_t* path, uint8_t path_len);

  // storage concepts, for sub-classes to override/implement
  virtual int  getBlobByKey(const uint8_t key[], int key_len, uint8_t dest_buf[]) { return 0; }  // not implemented
@@ -127,7 +128,7 @@ protected:
  void stopConnection(const uint8_t* pub_key);
  bool hasConnectionTo(const uint8_t* pub_key);
  void markConnectionActive(const ContactInfo& contact);
-  bool checkConnectionsAck(const uint8_t* data);
+  ContactInfo* checkConnectionsAck(const uint8_t* data);
  void checkConnections();

 public:
--- a/src/helpers/ClientACL.cpp
+++ b/src/helpers/ClientACL.cpp
@@ -24,16 +24,17 @@ void ClientACL::load(FILESYSTEM* _fs) {
      while (!full) {
        ClientInfo c;
        uint8_t pub_key[32];
-        uint8_t unused[6];
+        uint8_t unused[2];
+
+        memset(&c, 0, sizeof(c));

        bool success = (file.read(pub_key, 32) == 32);
        success = success && (file.read((uint8_t *) &c.permissions, 1) == 1);
-        success = success && (file.read(unused, 6) == 6);
+        success = success && (file.read((uint8_t *) &c.extra.room.sync_since, 4) == 4);
+        success = success && (file.read(unused, 2) == 2);
        success = success && (file.read((uint8_t *)&c.out_path_len, 1) == 1);
        success = success && (file.read(c.out_path, 64) == 64);
        success = success && (file.read(c.shared_secret, PUB_KEY_SIZE) == PUB_KEY_SIZE);
-        c.last_timestamp = 0;  // transient
-        c.last_activity = 0;

        if (!success) break; // EOF

@@ -49,19 +50,20 @@ void ClientACL::load(FILESYSTEM* _fs) {
  }
 }

-void ClientACL::save(FILESYSTEM* _fs) {
+void ClientACL::save(FILESYSTEM* _fs, bool (*filter)(ClientInfo*)) {
  File file = openWrite(_fs, "/s_contacts");
  if (file) {
-    uint8_t unused[6];
+    uint8_t unused[2];
    memset(unused, 0, sizeof(unused));

    for (int i = 0; i < num_clients; i++) {
      auto c = &clients[i];
-      if (c->permissions == 0) continue;    // skip deleted entries
+      if (c->permissions == 0 || (filter && !filter(c))) continue;    // skip deleted entries, or by filter function

      bool success = (file.write(c->id.pub_key, 32) == 32);
      success = success && (file.write((uint8_t *) &c->permissions, 1) == 1);
-      success = success && (file.write(unused, 6) == 6);
+      success = success && (file.write((uint8_t *) &c->extra.room.sync_since, 4) == 4);
+      success = success && (file.write(unused, 2) == 2);
      success = success && (file.write((uint8_t *)&c->out_path_len, 1) == 1);
      success = success && (file.write(c->out_path, 64) == 64);
      success = success && (file.write(c->shared_secret, PUB_KEY_SIZE) == PUB_KEY_SIZE);
--- a/src/helpers/ClientACL.h
+++ b/src/helpers/ClientACL.h
@@ -18,7 +18,16 @@ struct ClientInfo {
  uint8_t shared_secret[PUB_KEY_SIZE];
  uint32_t last_timestamp;   // by THEIR clock  (transient)
  uint32_t last_activity;    // by OUR clock    (transient)
-
+  union  {
+    struct {
+      uint32_t sync_since;  // sync messages SINCE this timestamp (by OUR clock)
+      uint32_t pending_ack;
+      uint32_t push_post_timestamp;
+      unsigned long ack_timeout;
+      uint8_t  push_failures;
+    } room;
+  } extra;
+  
  bool isAdmin() const { return (permissions & PERM_ACL_ROLE_MASK) == PERM_ACL_ADMIN; }
 };

@@ -36,7 +45,7 @@ public:
    num_clients = 0;
  }
  void load(FILESYSTEM* _fs);
-  void save(FILESYSTEM* _fs);
+  void save(FILESYSTEM* _fs, bool (*filter)(ClientInfo*)=NULL);

  ClientInfo* getClient(const uint8_t* pubkey, int key_len);
  ClientInfo* putClient(const mesh::Identity& id, uint8_t init_perms);
--- a/src/helpers/esp32/SerialBLEInterface.cpp
+++ b/src/helpers/esp32/SerialBLEInterface.cpp
@@ -66,7 +66,7 @@ bool SerialBLEInterface::onSecurityRequest() {
 void SerialBLEInterface::onAuthenticationComplete(esp_ble_auth_cmpl_t cmpl) {
  if (cmpl.success) {
    BLE_DEBUG_PRINTLN(" - SecurityCallback - Authentication Success");
-    //deviceConnected = true;
+    deviceConnected = true;
  } else {
    BLE_DEBUG_PRINTLN(" - SecurityCallback - Authentication Failure*");

@@ -88,8 +88,6 @@ void SerialBLEInterface::onConnect(BLEServer* pServer, esp_ble_gatts_cb_param_t

 void SerialBLEInterface::onMtuChanged(BLEServer* pServer, esp_ble_gatts_cb_param_t* param) {
  BLE_DEBUG_PRINTLN("onMtuChanged(), mtu=%d", pServer->getPeerMTU(param->mtu.conn_id));
-
-  deviceConnected = true;
 }

 void SerialBLEInterface::onDisconnect(BLEServer* pServer) {
--- a/src/helpers/nrf52/SerialBLEInterface.cpp
+++ b/src/helpers/nrf52/SerialBLEInterface.cpp
@@ -86,7 +86,7 @@ void SerialBLEInterface::startAdv() {
   * https://developer.apple.com/library/content/qa/qa1931/_index.html   
   */
  Bluefruit.Advertising.restartOnDisconnect(false); // don't restart automatically as we handle it in onDisconnect
-  Bluefruit.Advertising.setInterval(32, 1600);
+  Bluefruit.Advertising.setInterval(32, 244);
  Bluefruit.Advertising.setFastTimeout(30);      // number of seconds in fast mode
  Bluefruit.Advertising.start(0);                // 0 = Don't stop advertising after n seconds

--- a/src/helpers/ui/DisplayDriver.h
+++ b/src/helpers/ui/DisplayDriver.h
@@ -1,6 +1,7 @@
 #pragma once

 #include <stdint.h>
+#include <string.h>

 class DisplayDriver {
  int _w, _h;
@@ -31,5 +32,60 @@ public:
    setCursor(mid_x - w/2, y);
    print(str);
  }
+  
+  // convert UTF-8 characters to displayable block characters for compatibility
+  virtual void translateUTF8ToBlocks(char* dest, const char* src, size_t dest_size) {
+    size_t j = 0;
+    for (size_t i = 0; src[i] != 0 && j < dest_size - 1; i++) {
+      unsigned char c = (unsigned char)src[i];
+      if (c >= 32 && c <= 126) {
+        dest[j++] = c;  // ASCII printable
+      } else if (c >= 0x80) {
+        dest[j++] = '\xDB';  // CP437 full block █
+        while (src[i+1] && (src[i+1] & 0xC0) == 0x80) 
+          i++;  // skip UTF-8 continuation bytes
+      }
+    }
+    dest[j] = 0;
+  }
+  
+  // draw text with ellipsis if it exceeds max_width
+  virtual void drawTextEllipsized(int x, int y, int max_width, const char* str) {
+    char temp_str[256];  // reasonable buffer size
+    size_t len = strlen(str);
+    if (len >= sizeof(temp_str)) len = sizeof(temp_str) - 1;
+    memcpy(temp_str, str, len);
+    temp_str[len] = 0;
+    
+    if (getTextWidth(temp_str) <= max_width) {
+      setCursor(x, y);
+      print(temp_str);
+      return;
+    }
+    
+    // for variable-width fonts (GxEPD), add space after ellipsis
+    // for fixed-width fonts (OLED), keep tight spacing to save precious characters
+    const char* ellipsis;
+    // use a simple heuristic: if 'i' and 'l' have different widths, it's variable-width
+    int i_width = getTextWidth("i");
+    int l_width = getTextWidth("l");
+    if (i_width != l_width) {
+      ellipsis = "... ";  // variable-width fonts: add space
+    } else {
+      ellipsis = "...";   // fixed-width fonts: no space
+    }
+    
+    int ellipsis_width = getTextWidth(ellipsis);
+    int str_len = strlen(temp_str);
+    
+    while (str_len > 0 && getTextWidth(temp_str) > max_width - ellipsis_width) {
+      temp_str[--str_len] = 0;
+    }
+    strcat(temp_str, ellipsis);
+    
+    setCursor(x, y);
+    print(temp_str);
+  }
+  
  virtual void endFrame() = 0;
 };
--- a/src/helpers/ui/GenericVibration.cpp
+++ b/src/helpers/ui/GenericVibration.cpp
@@ -0,0 +1,38 @@
+#ifdef PIN_VIBRATION
+#include "GenericVibration.h"
+
+void GenericVibration::begin() {
+  pinMode(PIN_VIBRATION, OUTPUT);
+  digitalWrite(PIN_VIBRATION, LOW);
+  duration = 0;
+}
+
+void GenericVibration::trigger() {
+  duration = millis();
+  digitalWrite(PIN_VIBRATION, HIGH);
+}
+
+void GenericVibration::loop() {
+  if (isVibrating()) {
+    if ((millis() / 1000) % 2 == 0) {
+      digitalWrite(PIN_VIBRATION, LOW);
+    } else {
+      digitalWrite(PIN_VIBRATION, HIGH);
+    }
+
+    if (millis() - duration > VIBRATION_TIMEOUT) {
+      stop();
+    }
+  }
+}
+
+bool GenericVibration::isVibrating() {
+  return duration > 0;
+}
+
+void GenericVibration::stop() {
+  duration = 0;
+  digitalWrite(PIN_VIBRATION, LOW);
+}
+
+#endif // ifdef PIN_VIBRATION
--- a/src/helpers/ui/GenericVibration.h
+++ b/src/helpers/ui/GenericVibration.h
@@ -0,0 +1,33 @@
+#pragma once
+
+#ifdef PIN_VIBRATION
+
+#include <Arduino.h>
+
+/*
+ * Vibration motor control class
+ *
+ * Provides vibration feedback for events like new messages and new contacts
+ * Features:
+ * - 1-second vibration pulse
+ * - 5-second nag timeout (cooldown between vibrations)
+ * - Non-blocking operation
+ */
+
+#ifndef VIBRATION_TIMEOUT
+#define VIBRATION_TIMEOUT 5000 // 5 seconds default
+#endif
+
+class GenericVibration {
+public:
+  void begin();       // set up vibration pin
+  void trigger();     // trigger vibration if cooldown has passed
+  void loop();        // non-blocking timer handling
+  bool isVibrating(); // returns true if currently vibrating
+  void stop();        // stop vibration immediately
+
+private:
+  unsigned long duration;
+};
+
+#endif // ifdef PIN_VIBRATION
--- a/variants/ebyte_eora_s3/platformio.ini
+++ b/variants/ebyte_eora_s3/platformio.ini
@@ -0,0 +1,136 @@
+[Ebyte_EoRa-S3]
+extends = esp32_base
+board = ebyte_eora-s3
+build_flags =
+  ${esp32_base.build_flags}
+  -I variants/ebyte_eora_s3
+  -D EBYTE_EORA_S3
+  -D P_LORA_DIO_1=33
+  -D P_LORA_NSS=7
+  -D P_LORA_RESET=8   ; RADIOLIB_NC
+  -D P_LORA_BUSY=34
+  -D P_LORA_SCLK=5
+  -D P_LORA_MISO=3
+  -D P_LORA_MOSI=6
+  -D P_LORA_TX_LED=37
+  -D PIN_VBAT_READ=1
+  -D PIN_USER_BTN=0
+  -D PIN_BOARD_SDA=18
+  -D PIN_BOARD_SCL=17
+
+; SD_DAT0/MISO - GPIO2
+; SD_DAT1 - GPIO4
+; SD_CMD/MOSI - GPIO11
+; SD_DAT2 - GPIO112
+; SD_DAT3/CS - GPIO113
+; SD_CLK - GPIO114
+  -D PIN_BOARD_SDA=18
+  -D PIN_BOARD_SCL=17
+
+  -D SX126X_DIO2_AS_RF_SWITCH=true
+  -D SX126X_DIO3_TCXO_VOLTAGE=1.8
+  -D SX126X_CURRENT_LIMIT=140
+  -D RADIO_CLASS=CustomSX1262
+  -D WRAPPER_CLASS=CustomSX1262Wrapper
+  -D LORA_TX_POWER=22
+  -D SX126X_RX_BOOSTED_GAIN=1
+build_src_filter = ${esp32_base.build_src_filter}
+  +<../variants/ebyte_eora_s3>
+lib_deps =
+  ${esp32_base.lib_deps}
+  adafruit/Adafruit SSD1306 @ ^2.5.13
+
+; === EByte EORA_S3 with SX1262 environments ===
+[env:Ebyte_EoRa-S3_Repeater]
+extends = Ebyte_EoRa-S3
+build_flags =
+  ${Ebyte_EoRa-S3.build_flags}
+  -D DISPLAY_CLASS=SSD1306Display
+  -D ADVERT_NAME='"EORA_S3-1262 Repeater"'
+  -D ADVERT_LAT=0.0
+  -D ADVERT_LON=0.0
+  -D ADMIN_PASSWORD='"password"'
+  -D MAX_NEIGHBOURS=8
+;  -D MESH_PACKET_LOGGING=1
+;  -D MESH_DEBUG=1
+build_src_filter = ${Ebyte_EoRa-S3.build_src_filter}
+  +<helpers/ui/SSD1306Display.cpp>
+  +<../examples/simple_repeater>
+lib_deps =
+  ${Ebyte_EoRa-S3.lib_deps}
+  ${esp32_ota.lib_deps}
+
+[env:Ebyte_EoRa-S3_terminal_chat]
+extends = Ebyte_EoRa-S3
+build_flags =
+  ${Ebyte_EoRa-S3.build_flags}
+  -D MAX_CONTACTS=300
+  -D MAX_GROUP_CHANNELS=1
+;  -D MESH_PACKET_LOGGING=1
+;  -D MESH_DEBUG=1
+build_src_filter = ${Ebyte_EoRa-S3.build_src_filter}
+  +<../examples/simple_secure_chat/main.cpp>
+lib_deps =
+  ${Ebyte_EoRa-S3.lib_deps}
+  densaugeo/base64 @ ~1.4.0
+
+[env:Ebyte_EoRa-S3_room_server]
+extends = Ebyte_EoRa-S3
+build_flags =
+  ${Ebyte_EoRa-S3.build_flags}
+  -D DISPLAY_CLASS=SSD1306Display
+  -D ADVERT_NAME='"EORA_S3-1262 Room"'
+  -D ADVERT_LAT=0.0
+  -D ADVERT_LON=0.0
+  -D ADMIN_PASSWORD='"password"'
+  -D ROOM_PASSWORD='"hello"'
+;  -D MESH_PACKET_LOGGING=1
+;  -D MESH_DEBUG=1
+build_src_filter = ${Ebyte_EoRa-S3.build_src_filter}
+  +<helpers/ui/SSD1306Display.cpp>
+  +<../examples/simple_room_server>
+lib_deps =
+  ${Ebyte_EoRa-S3.lib_deps}
+  ${esp32_ota.lib_deps}
+
+[env:Ebyte_EoRa-S3_companion_radio_usb]
+extends = Ebyte_EoRa-S3
+build_flags =
+  ${Ebyte_EoRa-S3.build_flags}
+  -I examples/companion_radio/ui-new
+  -D DISPLAY_CLASS=SSD1306Display
+  -D MAX_CONTACTS=300
+  -D MAX_GROUP_CHANNELS=8
+; NOTE: DO NOT ENABLE -->  -D MESH_PACKET_LOGGING=1
+; NOTE: DO NOT ENABLE -->  -D MESH_DEBUG=1
+build_src_filter = ${Ebyte_EoRa-S3.build_src_filter}
+  +<helpers/ui/SSD1306Display.cpp>
+  +<helpers/ui/MomentaryButton.cpp>
+  +<../examples/companion_radio/*.cpp>
+  +<../examples/companion_radio/ui-new/*.cpp>
+lib_deps =
+  ${Ebyte_EoRa-S3.lib_deps}
+  densaugeo/base64 @ ~1.4.0
+
+[env:Ebyte_EoRa-S3_companion_radio_ble]
+extends = Ebyte_EoRa-S3
+build_flags =
+  ${Ebyte_EoRa-S3.build_flags}
+  -I examples/companion_radio/ui-new
+  -D DISPLAY_CLASS=SSD1306Display
+  -D MAX_CONTACTS=300
+  -D MAX_GROUP_CHANNELS=8
+  -D BLE_PIN_CODE=123456
+  -D BLE_DEBUG_LOGGING=1
+  -D OFFLINE_QUEUE_SIZE=256
+;  -D MESH_PACKET_LOGGING=1
+;  -D MESH_DEBUG=1
+build_src_filter = ${Ebyte_EoRa-S3.build_src_filter}
+  +<helpers/esp32/*.cpp>
+  +<helpers/ui/SSD1306Display.cpp>
+  +<helpers/ui/MomentaryButton.cpp>
+  +<../examples/companion_radio/*.cpp>
+  +<../examples/companion_radio/ui-new/*.cpp>
+lib_deps =
+  ${Ebyte_EoRa-S3.lib_deps}
+  densaugeo/base64 @ ~1.4.0
--- a/variants/ebyte_eora_s3/target.cpp
+++ b/variants/ebyte_eora_s3/target.cpp
@@ -0,0 +1,85 @@
+#include <Arduino.h>
+#include "target.h"
+
+ESP32Board board;
+
+#if defined(P_LORA_SCLK)
+  static SPIClass spi;
+  RADIO_CLASS radio = new Module(P_LORA_NSS, P_LORA_DIO_1, P_LORA_RESET, P_LORA_BUSY, spi);
+#else
+  RADIO_CLASS radio = new Module(P_LORA_NSS, P_LORA_DIO_1, P_LORA_RESET, P_LORA_BUSY);
+#endif
+
+WRAPPER_CLASS radio_driver(radio, board);
+
+ESP32RTCClock fallback_clock;
+AutoDiscoverRTCClock rtc_clock(fallback_clock);
+SensorManager sensors;
+
+#ifdef DISPLAY_CLASS
+  DISPLAY_CLASS display;
+  MomentaryButton user_btn(PIN_USER_BTN, 1000, true);
+#endif
+
+#ifndef LORA_CR
+  #define LORA_CR      5
+#endif
+
+bool radio_init() {
+  fallback_clock.begin();
+  rtc_clock.begin(Wire);
+  
+#ifdef SX126X_DIO3_TCXO_VOLTAGE
+  float tcxo = SX126X_DIO3_TCXO_VOLTAGE;
+#else
+  float tcxo = 1.6f;
+#endif
+
+#if defined(P_LORA_SCLK)
+  spi.begin(P_LORA_SCLK, P_LORA_MISO, P_LORA_MOSI);
+#endif
+  int status = radio.begin(LORA_FREQ, LORA_BW, LORA_SF, LORA_CR, RADIOLIB_SX126X_SYNC_WORD_PRIVATE, LORA_TX_POWER, 8, tcxo);
+  if (status != RADIOLIB_ERR_NONE) {
+    Serial.print("ERROR: radio init failed: ");
+    Serial.println(status);
+    return false;  // fail
+  }
+  
+  radio.setCRC(1);
+  
+#if defined(SX126X_RXEN) && defined(SX126X_TXEN)
+  radio.setRfSwitchPins(SX126X_RXEN, SX126X_TXEN);
+#endif
+
+#ifdef SX126X_CURRENT_LIMIT
+  radio.setCurrentLimit(SX126X_CURRENT_LIMIT);
+#endif
+#ifdef SX126X_DIO2_AS_RF_SWITCH
+  radio.setDio2AsRfSwitch(SX126X_DIO2_AS_RF_SWITCH);
+#endif
+#ifdef SX126X_RX_BOOSTED_GAIN
+  radio.setRxBoostedGainMode(SX126X_RX_BOOSTED_GAIN);
+#endif
+
+  return true;  // success
+}
+
+uint32_t radio_get_rng_seed() {
+  return radio.random(0x7FFFFFFF);
+}
+
+void radio_set_params(float freq, float bw, uint8_t sf, uint8_t cr) {
+  radio.setFrequency(freq);
+  radio.setSpreadingFactor(sf);
+  radio.setBandwidth(bw);
+  radio.setCodingRate(cr);
+}
+
+void radio_set_tx_power(uint8_t dbm) {
+  radio.setOutputPower(dbm);
+}
+
+mesh::LocalIdentity radio_new_identity() {
+  RadioNoiseListener rng(radio);
+  return mesh::LocalIdentity(&rng);  // create new random identity
+}
--- a/variants/ebyte_eora_s3/target.h
+++ b/variants/ebyte_eora_s3/target.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#define RADIOLIB_STATIC_ONLY 1
+#include <RadioLib.h>
+#include <helpers/radiolib/RadioLibWrappers.h>
+#include <helpers/ESP32Board.h>
+#include <helpers/radiolib/CustomSX1262Wrapper.h>
+#include <helpers/AutoDiscoverRTCClock.h>
+#include <helpers/SensorManager.h>
+#ifdef DISPLAY_CLASS
+  #include <helpers/ui/SSD1306Display.h>
+  #include <helpers/ui/MomentaryButton.h>
+#endif
+
+extern ESP32Board board;
+extern WRAPPER_CLASS radio_driver;
+extern AutoDiscoverRTCClock rtc_clock;
+extern SensorManager sensors;
+
+#ifdef DISPLAY_CLASS
+  extern DISPLAY_CLASS display;
+  extern MomentaryButton user_btn;
+#endif
+
+bool radio_init();
+uint32_t radio_get_rng_seed();
+void radio_set_params(float freq, float bw, uint8_t sf, uint8_t cr);
+void radio_set_tx_power(uint8_t dbm);
+mesh::LocalIdentity radio_new_identity();
--- a/variants/rak_wismesh_tag/platformio.ini
+++ b/variants/rak_wismesh_tag/platformio.ini
@@ -28,14 +28,12 @@ build_flags = ${nrf52_base.build_flags}
  -D PIN_BOARD_SCL=PIN_WIRE_SCL
 build_src_filter = ${nrf52_base.build_src_filter}
  +<../variants/rak_wismesh_tag>
-  +<helpers/ui/buzzer.cpp>
  +<helpers/ui/MomentaryButton.cpp>
  +<helpers/ui/NullDisplayDriver.cpp>
  +<helpers/sensors>
 lib_deps =
  ${nrf52_base.lib_deps}
  ${sensor_base.lib_deps}
-  end2endzone/NonBlockingRTTTL@^1.3.0

 [env:RAK_WisMesh_Tag_Repeater]
 extends = rak_wismesh_tag
@@ -77,11 +75,13 @@ build_flags =
 ; NOTE: DO NOT ENABLE -->  -D MESH_PACKET_LOGGING=1
 ; NOTE: DO NOT ENABLE -->  -D MESH_DEBUG=1
 build_src_filter = ${rak_wismesh_tag.build_src_filter}
+  +<helpers/ui/buzzer.cpp>
  +<../examples/companion_radio/*.cpp>
  +<../examples/companion_radio/ui-orig/*.cpp>
 lib_deps =
  ${rak_wismesh_tag.lib_deps}
  densaugeo/base64 @ ~1.4.0
+  end2endzone/NonBlockingRTTTL@^1.3.0

 [env:RAK_WisMesh_Tag_companion_radio_ble]
 extends = rak_wismesh_tag
@@ -98,12 +98,14 @@ build_flags =
 ;  -D MESH_PACKET_LOGGING=1
  -D MESH_DEBUG=1
 build_src_filter = ${rak_wismesh_tag.build_src_filter}
+  +<helpers/ui/buzzer.cpp>
  +<helpers/nrf52/SerialBLEInterface.cpp>
  +<../examples/companion_radio/*.cpp>
  +<../examples/companion_radio/ui-orig/*.cpp>
 lib_deps =
  ${rak4631.lib_deps}
  densaugeo/base64 @ ~1.4.0
+  end2endzone/NonBlockingRTTTL@^1.3.0

 [env:RAK_WisMesh_Tag_sensor]
 extends = rak4631
--- a/variants/sensecap_solar/platformio.ini
+++ b/variants/sensecap_solar/platformio.ini
@@ -3,10 +3,12 @@ extends = nrf52_base
 board = seeed_sensecap_solar
 board_build.ldscript = boards/nrf52840_s140_v7.ld
 build_flags = ${nrf52_base.build_flags}
+  ${sensor_base.build_flags}
  -I lib/nrf52/s140_nrf52_7.3.0_API/include
  -I lib/nrf52/s140_nrf52_7.3.0_API/include/nrf52
  -I variants/sensecap_solar
  -I src/helpers/nrf52
+  -UENV_INCLUDE_GPS
  -D NRF52_PLATFORM=1
  -D RADIO_CLASS=CustomSX1262
  -D WRAPPER_CLASS=CustomSX1262Wrapper
@@ -22,13 +24,6 @@ build_flags = ${nrf52_base.build_flags}
  -D SX126X_DIO3_TCXO_VOLTAGE=1.8
  -D SX126X_CURRENT_LIMIT=140
  -D SX126X_RX_BOOSTED_GAIN=1
-  -D ENV_INCLUDE_AHTX0=1
-  -D ENV_INCLUDE_BME280=1
-  -D ENV_INCLUDE_BMP280=1
-  -D ENV_INCLUDE_SHTC3=1
-  -D ENV_INCLUDE_LPS22HB=1
-  -D ENV_INCLUDE_INA3221=1
-  -D ENV_INCLUDE_INA219=1
 build_src_filter = ${nrf52_base.build_src_filter}
  +<helpers/*.cpp>
  +<helpers/sensors>
@@ -37,13 +32,7 @@ debug_tool = jlink
 upload_protocol = nrfutil
 lib_deps =
  ${nrf52_base.lib_deps}
-  adafruit/Adafruit INA3221 Library @ ^1.0.1
-  adafruit/Adafruit INA219 @ ^1.2.3
-  adafruit/Adafruit AHTX0 @ ^2.0.5
-  adafruit/Adafruit BME280 Library @ ^2.3.0
-  adafruit/Adafruit BMP280 Library @ ^2.6.8
-  adafruit/Adafruit SHTC3 Library @ ^1.0.1
-  arduino-libraries/Arduino_LPS22HB @ ^1.0.2
+  ${sensor_base.lib_deps}

 [env:SenseCap_Solar_repeater]
 extends = SenseCap_Solar
--- a/variants/tiny_relay/platformio.ini
+++ b/variants/tiny_relay/platformio.ini
@@ -0,0 +1,44 @@
+[Tiny_Relay]
+extends = stm32_base
+board = tiny_relay
+board_upload.maximum_size = 229376 ; 32kb for FS
+build_flags = ${stm32_base.build_flags}
+  -D RADIO_CLASS=CustomSTM32WLx
+  -D WRAPPER_CLASS=CustomSTM32WLxWrapper
+  -D SPI_INTERFACES_COUNT=0
+  -D RX_BOOSTED_GAIN=true
+;  -D STM32WL_TCXO_VOLTAGE=1.6 ; defaults to 0 if undef
+;  -D LORA_TX_POWER=14 ; Defaults to 22 for HP, 14 is for LP version
+  -D LORA_TX_POWER=22 ; Enable 22dBm transmission
+  -D MAX_LORA_TX_POWER=22 ; Allow setting up to 22dBm in companion radio
+  -I variants/tiny_relay
+build_src_filter = ${stm32_base.build_src_filter}
+  +<../variants/tiny_relay>
+
+[env:Tiny_Relay-repeater]
+extends = Tiny_Relay
+build_flags = ${Tiny_Relay.build_flags}
+  -D ADVERT_NAME='"tiny_relay Repeater"'
+  -D ADMIN_PASSWORD='"password"'
+build_src_filter = ${Tiny_Relay.build_src_filter}
+  +<../examples/simple_repeater/main.cpp>
+
+[env:Tiny_Relay-sensor]
+extends = Tiny_Relay
+build_flags = ${Tiny_Relay.build_flags}
+  -D ADVERT_NAME='"tiny_relay Sensor"'
+  -D ADMIN_PASSWORD='"password"'
+build_src_filter = ${Tiny_Relay.build_src_filter}
+  +<../examples/simple_sensor>
+
+[env:Tiny_Relay_companion_radio_usb]
+extends = Tiny_Relay
+build_flags = ${Tiny_Relay.build_flags}
+;  -D FORMAT_FS=true
+  -D MAX_CONTACTS=100
+  -D MAX_GROUP_CHANNELS=8
+  -D MAX_LORA_TX_POWER=22
+build_src_filter = ${Tiny_Relay.build_src_filter}
+  +<../examples/companion_radio/*.cpp>
+lib_deps = ${Tiny_Relay.lib_deps}
+  densaugeo/base64 @ ~1.4.0
--- a/variants/tiny_relay/target.cpp
+++ b/variants/tiny_relay/target.cpp
@@ -0,0 +1,82 @@
+#include "target.h"
+#include <Arduino.h>
+#include <helpers/ArduinoHelpers.h>
+
+TinyRelayBoard board;
+
+RADIO_CLASS radio = new STM32WLx_Module();
+
+WRAPPER_CLASS radio_driver(radio, board);
+
+static const uint32_t rfswitch_pins[] = {LORAWAN_RFSWITCH_PINS, RADIOLIB_NC, RADIOLIB_NC, RADIOLIB_NC};
+static const Module::RfSwitchMode_t rfswitch_table[] = {
+    {STM32WLx::MODE_IDLE, {LOW, LOW}},
+    {STM32WLx::MODE_RX, {HIGH, LOW}},
+    {STM32WLx::MODE_TX_LP, {LOW, HIGH}},
+    {STM32WLx::MODE_TX_HP, {LOW, HIGH}},
+    END_OF_MODE_TABLE,
+};
+
+VolatileRTCClock rtc_clock;
+SensorManager sensors;
+
+#ifndef LORA_CR
+#define LORA_CR 5
+#endif
+
+#ifndef STM32WL_TCXO_VOLTAGE
+// TCXO set to 0 for RAK3172
+#define STM32WL_TCXO_VOLTAGE 0
+#endif
+
+#ifndef LORA_TX_POWER
+#define LORA_TX_POWER 22
+#endif
+
+bool radio_init()
+{
+    //  rtc_clock.begin(Wire);
+
+    radio.setRfSwitchTable(rfswitch_pins, rfswitch_table);
+
+    int status = radio.begin(LORA_FREQ, LORA_BW, LORA_SF, LORA_CR, RADIOLIB_SX126X_SYNC_WORD_PRIVATE, LORA_TX_POWER, 16,
+                             STM32WL_TCXO_VOLTAGE, 0);
+
+    if (status != RADIOLIB_ERR_NONE) {
+        Serial.print("ERROR: radio init failed: ");
+        Serial.println(status);
+        return false; // fail
+    }
+
+#ifdef RX_BOOSTED_GAIN
+    radio.setRxBoostedGainMode(RX_BOOSTED_GAIN);
+#endif
+
+    radio.setCRC(1);
+
+    return true; // success
+}
+
+uint32_t radio_get_rng_seed()
+{
+    return radio.random(0x7FFFFFFF);
+}
+
+void radio_set_params(float freq, float bw, uint8_t sf, uint8_t cr)
+{
+    radio.setFrequency(freq);
+    radio.setSpreadingFactor(sf);
+    radio.setBandwidth(bw);
+    radio.setCodingRate(cr);
+}
+
+void radio_set_tx_power(uint8_t dbm)
+{
+    radio.setOutputPower(dbm);
+}
+
+mesh::LocalIdentity radio_new_identity()
+{
+    RadioNoiseListener rng(radio);
+    return mesh::LocalIdentity(&rng); // create new random identity
+}
--- a/variants/tiny_relay/target.h
+++ b/variants/tiny_relay/target.h
@@ -0,0 +1,59 @@
+#pragma once
+
+#define RADIOLIB_STATIC_ONLY 1
+#include <RadioLib.h>
+#include <helpers/ArduinoHelpers.h>
+#include <helpers/SensorManager.h>
+#include <helpers/radiolib/CustomSTM32WLxWrapper.h>
+#include <helpers/radiolib/RadioLibWrappers.h>
+#include <helpers/stm32/STM32Board.h>
+
+#define PIN_VBAT_READ A0
+#define ADC_MULTIPLIER (5 * 1.73 * 1000)
+
+class TinyRelayBoard : public STM32Board
+{
+  public:
+    void begin() override
+    {
+        STM32Board::begin();
+        pinMode(PA0, OUTPUT);
+        pinMode(PA1, OUTPUT);
+    }
+
+    const char *getManufacturerName() const override { return "Tiny Relay"; }
+
+    uint16_t getBattMilliVolts() override
+    {
+        analogReadResolution(12);
+        uint32_t raw = 0;
+        for (int i = 0; i < 8; i++) {
+            raw += analogRead(PIN_VBAT_READ);
+        }
+        return ((double)raw) * ADC_MULTIPLIER / 8 / 4096;
+    }
+
+    void setGpio(uint32_t values) override
+    {
+        // set led values
+        digitalWrite(PA0, values & 1);
+        digitalWrite(PA1, (values & 2) >> 1);
+    }
+
+    uint32_t getGpio() override
+    {
+        // get led value
+        return (digitalRead(PA1) << 1) | digitalRead(PA0);
+    }
+};
+
+extern TinyRelayBoard board;
+extern WRAPPER_CLASS radio_driver;
+extern VolatileRTCClock rtc_clock;
+extern SensorManager sensors;
+
+bool radio_init();
+uint32_t radio_get_rng_seed();
+void radio_set_params(float freq, float bw, uint8_t sf, uint8_t cr);
+void radio_set_tx_power(uint8_t dbm);
+mesh::LocalIdentity radio_new_identity();
--- a/variants/tiny_relay/variant.h
+++ b/variants/tiny_relay/variant.h
@@ -0,0 +1,5 @@
+#pragma once
+
+#include <variant_RAK3172_MODULE.h>
+
+#undef RNG
--- a/variants/xiao_nrf52/XiaoNrf52Board.cpp
+++ b/variants/xiao_nrf52/XiaoNrf52Board.cpp
@@ -1,21 +1,19 @@
 #ifdef XIAO_NRF52

 #include <Arduino.h>
-#include "XiaoNrf52Board.h"
-
-#include <bluefruit.h>
 #include <Wire.h>
+#include <bluefruit.h>
+
+#include "XiaoNrf52Board.h"

 static BLEDfu bledfu;

-static void connect_callback(uint16_t conn_handle)
-{
+static void connect_callback(uint16_t conn_handle) {
  (void)conn_handle;
  MESH_DEBUG_PRINTLN("BLE client connected");
 }

-static void disconnect_callback(uint16_t conn_handle, uint8_t reason)
-{
+static void disconnect_callback(uint16_t conn_handle, uint8_t reason) {
  (void)conn_handle;
  (void)reason;

@@ -41,12 +39,12 @@ void XiaoNrf52Board::begin() {
  digitalWrite(P_LORA_TX_LED, HIGH);
 #endif

-//  pinMode(SX126X_POWER_EN, OUTPUT);
-//  digitalWrite(SX126X_POWER_EN, HIGH);
-  delay(10);   // give sx1262 some time to power up
+  //  pinMode(SX126X_POWER_EN, OUTPUT);
+  //  digitalWrite(SX126X_POWER_EN, HIGH);
+  delay(10); // give sx1262 some time to power up
 }

-bool XiaoNrf52Board::startOTAUpdate(const char* id, char reply[]) {
+bool XiaoNrf52Board::startOTAUpdate(const char *id, char reply[]) {
  // Config the peripheral connection with maximum bandwidth
  // more SRAM required by SoftDevice
  // Note: All config***() function must be called before begin()
@@ -86,10 +84,8 @@ bool XiaoNrf52Board::startOTAUpdate(const char* id, char reply[]) {
  Bluefruit.Advertising.start(0);             // 0 = Don't stop advertising after n seconds

  strcpy(reply, "OK - started");
+
  return true;
-
-
-  return false;
 }

 #endif
--- a/variants/xiao_nrf52/XiaoNrf52Board.h
+++ b/variants/xiao_nrf52/XiaoNrf52Board.h
@@ -5,20 +5,6 @@

 #ifdef XIAO_NRF52

-// redefine lora pins if using the S3 variant of SX1262 board
-#ifdef SX1262_XIAO_S3_VARIANT
-  #undef P_LORA_DIO_1
-  #undef P_LORA_BUSY
-  #undef P_LORA_RESET
-  #undef P_LORA_NSS
-  #undef SX126X_RXEN
-  #define  P_LORA_DIO_1       D0
-  #define  P_LORA_BUSY        D1
-  #define  P_LORA_RESET       D2
-  #define  P_LORA_NSS         D3
-  #define  SX126X_RXEN        D4
-#endif
-
 class XiaoNrf52Board : public mesh::MainBoard {
 protected:
  uint8_t startup_reason;
@@ -40,13 +26,13 @@ public:
    // Please read befor going further ;)
    // https://wiki.seeedstudio.com/XIAO_BLE#q3-what-are-the-considerations-when-using-xiao-nrf52840-sense-for-battery-charging

-    // We can't drive VBAT_ENABLE to HIGH as long 
+    // We can't drive VBAT_ENABLE to HIGH as long
    // as we don't know wether we are charging or not ...
    // this is a 3mA loss (4/1500)
    digitalWrite(VBAT_ENABLE, LOW);
    int adcvalue = 0;
    analogReadResolution(12);
-    analogReference(AR_INTERNAL_3_0);  
+    analogReference(AR_INTERNAL_3_0);
    delay(10);
    adcvalue = analogRead(PIN_VBAT);
    return (adcvalue * ADC_MULTIPLIER * AREF_VOLTAGE) / 4.096;
--- a/variants/xiao_nrf52/platformio.ini
+++ b/variants/xiao_nrf52/platformio.ini
@@ -1,37 +1,19 @@
-[nrf52840_xiao]
+[Xiao_nrf52]
 extends = nrf52_base
-platform_packages =
-  toolchain-gccarmnoneeabi@~1.100301.0
-  framework-arduinoadafruitnrf52
 board = seeed-xiao-afruitnrf52-nrf52840
 board_build.ldscript = boards/nrf52840_s140_v7.ld
 build_flags = ${nrf52_base.build_flags}
-  -D NRF52_PLATFORM -D XIAO_NRF52
+  ${sensor_base.build_flags}
  -I lib/nrf52/s140_nrf52_7.3.0_API/include
  -I lib/nrf52/s140_nrf52_7.3.0_API/include/nrf52
-lib_ignore =
-  BluetoothOTA
-  lvgl
-  lib5b4
-lib_deps =
-  ${nrf52_base.lib_deps}
-  rweather/Crypto @ ^0.4.0
-  adafruit/Adafruit INA3221 Library @ ^1.0.1
-  adafruit/Adafruit INA219 @ ^1.2.3
-  adafruit/Adafruit AHTX0 @ ^2.0.5
-  adafruit/Adafruit BME280 Library @ ^2.3.0  
-
-
-[Xiao_nrf52]
-extends = nrf52840_xiao
-;board_build.ldscript = boards/nrf52840_s140_v7.ld
-build_flags = ${nrf52840_xiao.build_flags}
-  -D P_LORA_TX_LED=11
  -I variants/xiao_nrf52
-  -I src/helpers/nrf52
+  -UENV_INCLUDE_GPS
+  -D NRF52_PLATFORM
+  -D XIAO_NRF52
  -D RADIO_CLASS=CustomSX1262
  -D WRAPPER_CLASS=CustomSX1262Wrapper
  -D LORA_TX_POWER=22
+  -D P_LORA_TX_LED=11
  -D P_LORA_DIO_1=D1
  -D P_LORA_RESET=D2
  -D P_LORA_BUSY=D3
@@ -42,18 +24,16 @@ build_flags = ${nrf52840_xiao.build_flags}
  -D SX126X_DIO3_TCXO_VOLTAGE=1.8
  -D SX126X_CURRENT_LIMIT=140
  -D SX126X_RX_BOOSTED_GAIN=1
-  -D PIN_WIRE_SCL=6
-  -D PIN_WIRE_SDA=7
-  -D ENV_INCLUDE_AHTX0=1
-  -D ENV_INCLUDE_BME280=1
-  -D ENV_INCLUDE_INA3221=1
-  -D ENV_INCLUDE_INA219=1
-build_src_filter = ${nrf52840_xiao.build_src_filter}
+  -D PIN_WIRE_SCL=D6
+  -D PIN_WIRE_SDA=D7
+build_src_filter = ${nrf52_base.build_src_filter}
  +<helpers/*.cpp>
  +<helpers/sensors>
  +<../variants/xiao_nrf52>
 debug_tool = jlink
 upload_protocol = nrfutil
+lib_deps = ${nrf52_base.lib_deps}
+  ${sensor_base.lib_deps}

 [env:Xiao_nrf52_companion_radio_ble]
 extends = Xiao_nrf52
@@ -94,12 +74,6 @@ lib_deps =
  ${Xiao_nrf52.lib_deps}
  densaugeo/base64 @ ~1.4.0

-[env:Xiao_nrf52_alt_pinout_companion_radio_ble]
-extends = env:Xiao_nrf52_companion_radio_ble
-build_flags =
-  ${env:Xiao_nrf52_companion_radio_ble.build_flags}
-  -D SX1262_XIAO_S3_VARIANT
-
 [env:Xiao_nrf52_repeater]
 extends = Xiao_nrf52
 build_flags =
@@ -114,12 +88,6 @@ build_flags =
 build_src_filter = ${Xiao_nrf52.build_src_filter}
  +<../examples/simple_repeater/*.cpp>

-[env:Xiao_nrf52_alt_pinout_repeater]
-extends = env:Xiao_nrf52_repeater
-build_flags =
-  ${env:Xiao_nrf52_repeater.build_flags}
-  -D SX1262_XIAO_S3_VARIANT
-
 [env:Xiao_nrf52_room_server]
 extends = Xiao_nrf52
 build_flags =
--- a/variants/xiao_nrf52/target.cpp
+++ b/variants/xiao_nrf52/target.cpp
@@ -10,12 +10,13 @@ WRAPPER_CLASS radio_driver(radio, board);

 VolatileRTCClock fallback_clock;
 AutoDiscoverRTCClock rtc_clock(fallback_clock);
+
 EnvironmentSensorManager sensors;

 bool radio_init() {
-    rtc_clock.begin(Wire);
-  
-    return radio.std_init(&SPI);
+  rtc_clock.begin(Wire);
+
+  return radio.std_init(&SPI);
 }

 uint32_t radio_get_rng_seed() {
@@ -35,5 +36,5 @@ void radio_set_tx_power(uint8_t dbm) {

 mesh::LocalIdentity radio_new_identity() {
  RadioNoiseListener rng(radio);
-  return mesh::LocalIdentity(&rng);  // create new random identity
+  return mesh::LocalIdentity(&rng); // create new random identity
 }
--- a/variants/xiao_nrf52/variant.cpp
+++ b/variants/xiao_nrf52/variant.cpp
@@ -1,86 +1,85 @@
 #include "variant.h"
+
+#include "nrf.h"
 #include "wiring_constants.h"
 #include "wiring_digital.h"
-#include "nrf.h"

-const uint32_t g_ADigitalPinMap[] =
-{
-    // D0 .. D10
-     2, // D0  is P0.02 (A0)
-     3, // D1  is P0.03 (A1)
-    28, // D2  is P0.28 (A2)
-    29, // D3  is P0.29 (A3)
-     4, // D4  is P0.04 (A4,SDA)
-     5, // D5  is P0.05 (A5,SCL)
-    43, // D6  is P1.11 (TX)
-    44, // D7  is P1.12 (RX)
-    45, // D8  is P1.13 (SCK)
-    46, // D9  is P1.14 (MISO)
-    47, // D10 is P1.15 (MOSI)
+const uint32_t g_ADigitalPinMap[] = {
+  // D0 .. D10
+  2,  // D0  is P0.02 (A0)
+  3,  // D1  is P0.03 (A1)
+  28, // D2  is P0.28 (A2)
+  29, // D3  is P0.29 (A3)
+  4,  // D4  is P0.04 (A4,SDA)
+  5,  // D5  is P0.05 (A5,SCL)
+  43, // D6  is P1.11 (TX)
+  44, // D7  is P1.12 (RX)
+  45, // D8  is P1.13 (SCK)
+  46, // D9  is P1.14 (MISO)
+  47, // D10 is P1.15 (MOSI)

-    // LEDs
-    26, // D11 is P0.26 (LED RED)
-     6, // D12 is P0.06 (LED BLUE)
-    30, // D13 is P0.30 (LED GREEN)
-    14, // D14 is P0.14 (READ_BAT)
+  // LEDs
+  26, // D11 is P0.26 (LED RED)
+  6,  // D12 is P0.06 (LED BLUE)
+  30, // D13 is P0.30 (LED GREEN)
+  14, // D14 is P0.14 (READ_BAT)

-    // LSM6DS3TR
-    40, // D15 is P1.08 (6D_PWR)
-    27, // D16 is P0.27 (6D_I2C_SCL)
-     7, // D17 is P0.07 (6D_I2C_SDA)
-    11, // D18 is P0.11 (6D_INT1)
+  // LSM6DS3TR
+  40, // D15 is P1.08 (6D_PWR)
+  27, // D16 is P0.27 (6D_I2C_SCL)
+  7,  // D17 is P0.07 (6D_I2C_SDA)
+  11, // D18 is P0.11 (6D_INT1)

-    // MIC
-    42, // D19 is P1.10 (MIC_PWR)
-    32, // D20 is P1.00 (PDM_CLK)
-    16, // D21 is P0.16 (PDM_DATA)
+  // MIC
+  42, // D19 is P1.10 (MIC_PWR)
+  32, // D20 is P1.00 (PDM_CLK)
+  16, // D21 is P0.16 (PDM_DATA)

-    // BQ25100
-    13, // D22 is P0.13 (HICHG)
-    17, // D23 is P0.17 (~CHG)
+  // BQ25100
+  13, // D22 is P0.13 (HICHG)
+  17, // D23 is P0.17 (~CHG)

-    //
-    21, // D24 is P0.21 (QSPI_SCK)
-    25, // D25 is P0.25 (QSPI_CSN)
-    20, // D26 is P0.20 (QSPI_SIO_0 DI)
-    24, // D27 is P0.24 (QSPI_SIO_1 DO)
-    22, // D28 is P0.22 (QSPI_SIO_2 WP)
-    23, // D29 is P0.23 (QSPI_SIO_3 HOLD)
+  //
+  21, // D24 is P0.21 (QSPI_SCK)
+  25, // D25 is P0.25 (QSPI_CSN)
+  20, // D26 is P0.20 (QSPI_SIO_0 DI)
+  24, // D27 is P0.24 (QSPI_SIO_1 DO)
+  22, // D28 is P0.22 (QSPI_SIO_2 WP)
+  23, // D29 is P0.23 (QSPI_SIO_3 HOLD)

-    // NFC
-     9, // D30 is P0.09 (NFC1)
-    10, // D31 is P0.10 (NFC2)
+  // NFC
+  9,  // D30 is P0.09 (NFC1)
+  10, // D31 is P0.10 (NFC2)

-    // VBAT
-    31, // D32 is P0.31 (VBAT)
+  // VBAT
+  31, // D32 is P0.31 (VBAT)
 };

-void initVariant()
-{
-    // Disable reading of the BAT voltage.
-    // https://wiki.seeedstudio.com/XIAO_BLE#q3-what-are-the-considerations-when-using-xiao-nrf52840-sense-for-battery-charging
-    pinMode(VBAT_ENABLE, OUTPUT);
-    //digitalWrite(VBAT_ENABLE, HIGH); 
-    // This was taken from Seeed github butis not coherent with the doc, 
-    // VBAT_ENABLE should be kept to LOW to protect P0.14, (1500/500)*(4.2-3.3)+3.3 = 3.9V > 3.6V
-    // This induces a 3mA current in the resistors :( but it's better than burning the nrf
-    digitalWrite(VBAT_ENABLE, LOW);
+void initVariant() {
+  // Disable reading of the BAT voltage.
+  // https://wiki.seeedstudio.com/XIAO_BLE#q3-what-are-the-considerations-when-using-xiao-nrf52840-sense-for-battery-charging
+  pinMode(VBAT_ENABLE, OUTPUT);
+  // digitalWrite(VBAT_ENABLE, HIGH);
+  //  This was taken from Seeed github butis not coherent with the doc,
+  //  VBAT_ENABLE should be kept to LOW to protect P0.14, (1500/500)*(4.2-3.3)+3.3 = 3.9V > 3.6V
+  //  This induces a 3mA current in the resistors :( but it's better than burning the nrf
+  digitalWrite(VBAT_ENABLE, LOW);

-    // Low charging current (50mA)
-    // https://wiki.seeedstudio.com/XIAO_BLE#battery-charging-current
-    //pinMode(PIN_CHARGING_CURRENT, INPUT);
+  // Low charging current (50mA)
+  // https://wiki.seeedstudio.com/XIAO_BLE#battery-charging-current
+  // pinMode(PIN_CHARGING_CURRENT, INPUT);

-    // High charging current (100mA)
-    pinMode(PIN_CHARGING_CURRENT, OUTPUT);
-    digitalWrite(PIN_CHARGING_CURRENT, LOW);
+  // High charging current (100mA)
+  pinMode(PIN_CHARGING_CURRENT, OUTPUT);
+  digitalWrite(PIN_CHARGING_CURRENT, LOW);

-    pinMode(PIN_QSPI_CS, OUTPUT);
-    digitalWrite(PIN_QSPI_CS, HIGH);
+  pinMode(PIN_QSPI_CS, OUTPUT);
+  digitalWrite(PIN_QSPI_CS, HIGH);

-    pinMode(LED_RED, OUTPUT);
-    digitalWrite(LED_RED, HIGH);
-    pinMode(LED_GREEN, OUTPUT);
-    digitalWrite(LED_GREEN, HIGH);
-    pinMode(LED_BLUE, OUTPUT);
-    digitalWrite(LED_BLUE, HIGH);
+  pinMode(LED_RED, OUTPUT);
+  digitalWrite(LED_RED, HIGH);
+  pinMode(LED_GREEN, OUTPUT);
+  digitalWrite(LED_GREEN, HIGH);
+  pinMode(LED_BLUE, OUTPUT);
+  digitalWrite(LED_BLUE, HIGH);
 }
--- a/variants/xiao_nrf52/variant.h
+++ b/variants/xiao_nrf52/variant.h
@@ -113,8 +113,8 @@ static const uint8_t A5  = PIN_A5;
 // #define PIN_WIRE_SDA            (17) // 4 and 5 are used for the sx1262 !
 // #define PIN_WIRE_SCL            (16) // use WIRE1_SDA

-static const uint8_t SDA = PIN_WIRE_SDA;
-static const uint8_t SCL = PIN_WIRE_SCL;
+// static const uint8_t SDA = PIN_WIRE_SDA;
+// static const uint8_t SCL = PIN_WIRE_SCL;

 //#define PIN_WIRE1_SDA           (17)
 //#define PIN_WIRE1_SCL           (16)