From 8435464c84fd86602f0b38bf77d33d7e065080e9 Mon Sep 17 00:00:00 2001
From: Quency-D <hj_zzns@163.com>
Date: Tue, 24 Mar 2026 10:48:15 +0800
Subject: [PATCH 01/23] Add v4 FEM LNA CLI control commands.

---
 docs/cli_commands.md                   | 14 +++++++++
 examples/companion_radio/DataStore.cpp |  2 ++
 examples/companion_radio/MyMesh.cpp    | 31 +++++++++++++++++++-
 examples/companion_radio/NodePrefs.h   |  3 +-
 examples/simple_repeater/MyMesh.cpp    |  2 ++
 examples/simple_room_server/MyMesh.cpp |  2 ++
 examples/simple_sensor/SensorMesh.cpp  |  2 ++
 src/MeshCore.h                         |  5 +++-
 src/helpers/CommonCLI.cpp              | 39 ++++++++++++++++++++++++--
 src/helpers/CommonCLI.h                |  1 +
 variants/heltec_v4/HeltecV4Board.cpp   | 18 ++++++++++++
 variants/heltec_v4/HeltecV4Board.h     |  3 ++
 variants/heltec_v4/LoRaFEMControl.h    |  3 +-
 13 files changed, 118 insertions(+), 7 deletions(-)

diff --git a/docs/cli_commands.md b/docs/cli_commands.md
index 9769d713..4dbf84e1 100644
--- a/docs/cli_commands.md
+++ b/docs/cli_commands.md
@@ -261,6 +261,20 @@ This document provides an overview of CLI commands that can be sent to MeshCore
 
 ---
 
+#### View or change the LoRa FEM receive-path gain state on supported boards
+**Usage:**
+- `get radio.fem.rxgain`
+- `set radio.fem.rxgain <state>`
+
+**Parameters:**
+- `state`: `on`|`off`
+
+**Notes:**
+- This controls the external LoRa FEM receive-path LNA where the board supports it.
+- This is separate from `radio.rxgain`, which controls the radio chip receive gain mode.
+
+---
+
 ### System
 
 #### View or change this node's name
diff --git a/examples/companion_radio/DataStore.cpp b/examples/companion_radio/DataStore.cpp
index 40f1ceeb..98a7a0dc 100644
--- a/examples/companion_radio/DataStore.cpp
+++ b/examples/companion_radio/DataStore.cpp
@@ -231,6 +231,7 @@ void DataStore::loadPrefsInt(const char *filename, NodePrefs& _prefs, double& no
     file.read((uint8_t *)&_prefs.autoadd_config, sizeof(_prefs.autoadd_config));           // 87
     file.read((uint8_t *)&_prefs.autoadd_max_hops, sizeof(_prefs.autoadd_max_hops));       // 88
     file.read((uint8_t *)&_prefs.rx_boosted_gain, sizeof(_prefs.rx_boosted_gain)); // 89
+    file.read((uint8_t *)&_prefs.radio_fem_rxgain, sizeof(_prefs.radio_fem_rxgain)); // 90
 
     file.close();
   }
@@ -269,6 +270,7 @@ void DataStore::savePrefs(const NodePrefs& _prefs, double node_lat, double node_
     file.write((uint8_t *)&_prefs.autoadd_config, sizeof(_prefs.autoadd_config));           // 87
     file.write((uint8_t *)&_prefs.autoadd_max_hops, sizeof(_prefs.autoadd_max_hops));       // 88
     file.write((uint8_t *)&_prefs.rx_boosted_gain, sizeof(_prefs.rx_boosted_gain)); // 89
+    file.write((uint8_t *)&_prefs.radio_fem_rxgain, sizeof(_prefs.radio_fem_rxgain)); // 90
 
     file.close();
   }
diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index b94e4526..d5d0abfe 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -46,7 +46,9 @@
 #define CMD_SET_CUSTOM_VAR            41
 #define CMD_GET_ADVERT_PATH           42
 #define CMD_GET_TUNING_PARAMS         43
-// NOTE: CMD range 44..49 parked, potentially for WiFi operations
+#define CMD_GET_RADIO_FEM_RXGAIN      44
+#define CMD_SET_RADIO_FEM_RXGAIN      45
+// NOTE: CMD range 46..49 parked, potentially for WiFi operations
 #define CMD_SEND_BINARY_REQ           50
 #define CMD_FACTORY_RESET             51
 #define CMD_SEND_PATH_DISCOVERY_REQ   52
@@ -828,6 +830,7 @@ MyMesh::MyMesh(mesh::Radio &radio, mesh::RNG &rng, mesh::RTCClock &rtc, SimpleMe
   _prefs.rx_boosted_gain = 1; // enabled by default
 #endif
 #endif
+  _prefs.radio_fem_rxgain = 1;
 }
 
 void MyMesh::begin(bool has_display) {
@@ -866,6 +869,7 @@ void MyMesh::begin(bool has_display) {
   _prefs.tx_power_dbm = constrain(_prefs.tx_power_dbm, -9, MAX_LORA_TX_POWER);
   _prefs.gps_enabled = constrain(_prefs.gps_enabled, 0, 1);  // Ensure boolean 0 or 1
   _prefs.gps_interval = constrain(_prefs.gps_interval, 0, 86400);  // Max 24 hours
+  _prefs.radio_fem_rxgain = constrain(_prefs.radio_fem_rxgain, 0, 1);
 
 #ifdef BLE_PIN_CODE // 123456 by default
   if (_prefs.ble_pin == 0) {
@@ -895,6 +899,7 @@ void MyMesh::begin(bool has_display) {
   radio_set_params(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
   radio_set_tx_power(_prefs.tx_power_dbm);
   radio_driver.setRxBoostedGainMode(_prefs.rx_boosted_gain);
+  board.setLoRaFemLnaEnabled(_prefs.radio_fem_rxgain);
   MESH_DEBUG_PRINTLN("RX Boosted Gain Mode: %s",
                      radio_driver.getRxBoostedGainMode() ? "Enabled" : "Disabled");
 }
@@ -1697,6 +1702,30 @@ void MyMesh::handleCmdFrame(size_t len) {
     } else {
       writeErrFrame(ERR_CODE_ILLEGAL_ARG);
     }
+  } else if (cmd_frame[0] == CMD_GET_RADIO_FEM_RXGAIN) {
+    if (!board.canControlLoRaFemLna()) {
+      writeErrFrame(ERR_CODE_UNSUPPORTED_CMD);
+    } else {
+      out_frame[0] = RESP_CODE_OK;
+      uint32_t value = board.isLoRaFemLnaEnabled() ? 1 : 0;
+      memcpy(&out_frame[1], &value, 4);
+      _serial->writeFrame(out_frame, 5);
+    }
+  } else if (cmd_frame[0] == CMD_SET_RADIO_FEM_RXGAIN && len >= 2) {
+    uint8_t value = cmd_frame[1];
+    if (!board.canControlLoRaFemLna()) {
+      writeErrFrame(ERR_CODE_UNSUPPORTED_CMD);
+    } else if (value <= 1) {
+      _prefs.radio_fem_rxgain = value;
+      if (board.setLoRaFemLnaEnabled(value != 0)) {
+        savePrefs();
+        writeOKFrame();
+      } else {
+        writeErrFrame(ERR_CODE_UNSUPPORTED_CMD);
+      }
+    } else {
+      writeErrFrame(ERR_CODE_ILLEGAL_ARG);
+    }
   } else if (cmd_frame[0] == CMD_GET_ADVERT_PATH && len >= PUB_KEY_SIZE+2) {
     // FUTURE use:  uint8_t reserved = cmd_frame[1];
     uint8_t *pub_key = &cmd_frame[2];
diff --git a/examples/companion_radio/NodePrefs.h b/examples/companion_radio/NodePrefs.h
index 557be306..7ecfdf7d 100644
--- a/examples/companion_radio/NodePrefs.h
+++ b/examples/companion_radio/NodePrefs.h
@@ -29,7 +29,8 @@ struct NodePrefs {  // persisted to file
   uint32_t gps_interval;     // GPS read interval in seconds
   uint8_t autoadd_config;    // bitmask for auto-add contacts config
   uint8_t rx_boosted_gain; // SX126x RX boosted gain mode (0=power saving, 1=boosted)
+  uint8_t radio_fem_rxgain;  // LoRa FEM RX gain setting
   uint8_t client_repeat;
   uint8_t path_hash_mode;    // which path mode to use when sending
   uint8_t autoadd_max_hops;  // 0 = no limit, 1 = direct (0 hops), N = up to N-1 hops (max 64)
-};
\ No newline at end of file
+};
diff --git a/examples/simple_repeater/MyMesh.cpp b/examples/simple_repeater/MyMesh.cpp
index 24e88949..92affc5a 100644
--- a/examples/simple_repeater/MyMesh.cpp
+++ b/examples/simple_repeater/MyMesh.cpp
@@ -896,6 +896,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.rx_boosted_gain = 1; // enabled by default;
 #endif
 #endif
+  _prefs.radio_fem_rxgain = 1;
 
   pending_discover_tag = 0;
   pending_discover_until = 0;
@@ -922,6 +923,7 @@ void MyMesh::begin(FILESYSTEM *fs) {
   radio_driver.setRxBoostedGainMode(_prefs.rx_boosted_gain);
   MESH_DEBUG_PRINTLN("RX Boosted Gain Mode: %s",
                      radio_driver.getRxBoostedGainMode() ? "Enabled" : "Disabled");
+  board.setLoRaFemLnaEnabled(_prefs.radio_fem_rxgain);
 
   updateAdvertTimer();
   updateFloodAdvertTimer();
diff --git a/examples/simple_room_server/MyMesh.cpp b/examples/simple_room_server/MyMesh.cpp
index 7b943773..7f61c266 100644
--- a/examples/simple_room_server/MyMesh.cpp
+++ b/examples/simple_room_server/MyMesh.cpp
@@ -631,6 +631,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.gps_enabled = 0;
   _prefs.gps_interval = 0;
   _prefs.advert_loc_policy = ADVERT_LOC_PREFS;
+  _prefs.radio_fem_rxgain = 1;
 
   next_post_idx = 0;
   next_client_idx = 0;
@@ -649,6 +650,7 @@ void MyMesh::begin(FILESYSTEM *fs) {
 
   radio_set_params(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
   radio_set_tx_power(_prefs.tx_power_dbm);
+  board.setLoRaFemLnaEnabled(_prefs.radio_fem_rxgain);
 
   updateAdvertTimer();
   updateFloodAdvertTimer();
diff --git a/examples/simple_sensor/SensorMesh.cpp b/examples/simple_sensor/SensorMesh.cpp
index 57d23a31..58490fd0 100644
--- a/examples/simple_sensor/SensorMesh.cpp
+++ b/examples/simple_sensor/SensorMesh.cpp
@@ -729,6 +729,7 @@ SensorMesh::SensorMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::Millise
   _prefs.gps_enabled = 0;
   _prefs.gps_interval = 0;
   _prefs.advert_loc_policy = ADVERT_LOC_PREFS;
+  _prefs.radio_fem_rxgain = 1;
 }
 
 void SensorMesh::begin(FILESYSTEM* fs) {
@@ -741,6 +742,7 @@ void SensorMesh::begin(FILESYSTEM* fs) {
 
   radio_set_params(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
   radio_set_tx_power(_prefs.tx_power_dbm);
+  board.setLoRaFemLnaEnabled(_prefs.radio_fem_rxgain);
 
   updateAdvertTimer();
   updateFloodAdvertTimer();
diff --git a/src/MeshCore.h b/src/MeshCore.h
index 70cd0f06..91b99c80 100644
--- a/src/MeshCore.h
+++ b/src/MeshCore.h
@@ -57,6 +57,9 @@ public:
   virtual uint8_t getStartupReason() const = 0;
   virtual bool getBootloaderVersion(char* version, size_t max_len) { return false; }
   virtual bool startOTAUpdate(const char* id, char reply[]) { return false; }   // not supported
+  virtual bool setLoRaFemLnaEnabled(bool enable) { return false; }
+  virtual bool canControlLoRaFemLna() const { return false; }
+  virtual bool isLoRaFemLnaEnabled() const { return false; }
 
   // Power management interface (boards with power management override these)
   virtual bool isExternalPowered() { return false; }
@@ -100,4 +103,4 @@ public:
   }
 };
 
-}
\ No newline at end of file
+}
diff --git a/src/helpers/CommonCLI.cpp b/src/helpers/CommonCLI.cpp
index 8b097c29..1c2afd37 100644
--- a/src/helpers/CommonCLI.cpp
+++ b/src/helpers/CommonCLI.cpp
@@ -88,7 +88,8 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     file.read((uint8_t *)&_prefs->adc_multiplier, sizeof(_prefs->adc_multiplier));                 // 166
     file.read((uint8_t *)_prefs->owner_info, sizeof(_prefs->owner_info));                          // 170
     file.read((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 290
-    // next: 291
+    file.read((uint8_t *)&_prefs->radio_fem_rxgain, sizeof(_prefs->radio_fem_rxgain));            // 291
+    // next: 292
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -118,6 +119,7 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
 
     // sanitise settings
     _prefs->rx_boosted_gain = constrain(_prefs->rx_boosted_gain, 0, 1); // boolean
+    _prefs->radio_fem_rxgain = constrain(_prefs->radio_fem_rxgain, 0, 1); // boolean
 
     file.close();
   }
@@ -179,7 +181,8 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write((uint8_t *)&_prefs->adc_multiplier, sizeof(_prefs->adc_multiplier));                 // 166
     file.write((uint8_t *)_prefs->owner_info, sizeof(_prefs->owner_info));                          // 170
     file.write((uint8_t *)&_prefs->rx_boosted_gain, sizeof(_prefs->rx_boosted_gain));              // 290
-    // next: 291
+    file.write((uint8_t *)&_prefs->radio_fem_rxgain, sizeof(_prefs->radio_fem_rxgain));            // 291
+    // next: 292
 
     file.close();
   }
@@ -327,6 +330,12 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
       } else if (memcmp(config, "radio.rxgain", 12) == 0) {
         sprintf(reply, "> %s", _prefs->rx_boosted_gain ? "on" : "off");
 #endif
+      } else if (memcmp(config, "radio.fem.rxgain", 16) == 0) {
+        if (!_board->canControlLoRaFemLna()) {
+          strcpy(reply, "Error: unsupported by this board");
+        } else {
+          sprintf(reply, "> %s", _board->isLoRaFemLnaEnabled() ? "on" : "off");
+        }
       } else if (memcmp(config, "radio", 5) == 0) {
         char freq[16], bw[16];
         strcpy(freq, StrHelper::ftoa(_prefs->freq));
@@ -520,13 +529,37 @@ void CommonCLI::handleCommand(uint32_t sender_timestamp, const char* command, ch
         _prefs->disable_fwd = memcmp(&config[7], "off", 3) == 0;
         savePrefs();
         strcpy(reply, _prefs->disable_fwd ? "OK - repeat is now OFF" : "OK - repeat is now ON");
-#if defined(USE_SX1262) || defined(USE_SX1268)
       } else if (memcmp(config, "radio.rxgain ", 13) == 0) {
+#if defined(USE_SX1262) || defined(USE_SX1268)
         _prefs->rx_boosted_gain = memcmp(&config[13], "on", 2) == 0;
         strcpy(reply, "OK");
         savePrefs();
         _callbacks->setRxBoostedGain(_prefs->rx_boosted_gain);
+#else
+        strcpy(reply, "Error: unsupported by this board");
 #endif
+      } else if (memcmp(config, "radio.fem.rxgain ", 17) == 0) {
+        if (!_board->canControlLoRaFemLna()) {
+          strcpy(reply, "Error: unsupported by this board");
+        } else if (memcmp(&config[17], "on", 2) == 0) {
+          if (_board->setLoRaFemLnaEnabled(true)) {
+            _prefs->radio_fem_rxgain = 1;
+            savePrefs();
+            strcpy(reply, "OK - LoRa FEM RX gain on");
+          } else {
+            strcpy(reply, "Error: failed to apply LoRa FEM RX gain");
+          }
+        } else if (memcmp(&config[17], "off", 3) == 0) {
+          if (_board->setLoRaFemLnaEnabled(false)) {
+            _prefs->radio_fem_rxgain = 0;
+            savePrefs();
+            strcpy(reply, "OK - LoRa FEM RX gain off");
+          } else {
+            strcpy(reply, "Error: failed to apply LoRa FEM RX gain");
+          }
+        } else {
+          strcpy(reply, "Error: state must be on or off");
+        }
       } else if (memcmp(config, "radio ", 6) == 0) {
         strcpy(tmp, &config[6]);
         const char *parts[4];
diff --git a/src/helpers/CommonCLI.h b/src/helpers/CommonCLI.h
index 3a4332d1..82d5fcda 100644
--- a/src/helpers/CommonCLI.h
+++ b/src/helpers/CommonCLI.h
@@ -58,6 +58,7 @@ struct NodePrefs { // persisted to file
   float adc_multiplier;
   char owner_info[120];
   uint8_t rx_boosted_gain; // power settings
+  uint8_t radio_fem_rxgain; // LoRa FEM RX gain setting
   uint8_t path_hash_mode;   // which path mode to use when sending
   uint8_t loop_detect;
 };
diff --git a/variants/heltec_v4/HeltecV4Board.cpp b/variants/heltec_v4/HeltecV4Board.cpp
index 49580d2e..4c79825a 100644
--- a/variants/heltec_v4/HeltecV4Board.cpp
+++ b/variants/heltec_v4/HeltecV4Board.cpp
@@ -83,3 +83,21 @@ void HeltecV4Board::begin() {
     return loRaFEMControl.getFEMType() == KCT8103L_PA ? "Heltec V4.3 OLED" : "Heltec V4 OLED";
 #endif
   }
+
+  bool HeltecV4Board::setLoRaFemLnaEnabled(bool enable) {
+    if (!loRaFEMControl.isLnaCanControl()) {
+      return false;
+    }
+
+    loRaFEMControl.setLNAEnable(enable);
+    loRaFEMControl.setRxModeEnable();
+    return true;
+  }
+
+  bool HeltecV4Board::canControlLoRaFemLna() const {
+    return loRaFEMControl.isLnaCanControl();
+  }
+
+  bool HeltecV4Board::isLoRaFemLnaEnabled() const {
+    return loRaFEMControl.isLNAEnabled();
+  }
diff --git a/variants/heltec_v4/HeltecV4Board.h b/variants/heltec_v4/HeltecV4Board.h
index 4d5ee461..fe77caed 100644
--- a/variants/heltec_v4/HeltecV4Board.h
+++ b/variants/heltec_v4/HeltecV4Board.h
@@ -19,5 +19,8 @@ public:
   void powerOff() override;
   uint16_t getBattMilliVolts() override;
   const char* getManufacturerName() const override ;
+  bool setLoRaFemLnaEnabled(bool enable) override;
+  bool canControlLoRaFemLna() const override;
+  bool isLoRaFemLnaEnabled() const override;
 
 };
diff --git a/variants/heltec_v4/LoRaFEMControl.h b/variants/heltec_v4/LoRaFEMControl.h
index 75452965..d84ebe9c 100644
--- a/variants/heltec_v4/LoRaFEMControl.h
+++ b/variants/heltec_v4/LoRaFEMControl.h
@@ -18,8 +18,9 @@ class LoRaFEMControl
     void setRxModeEnable(void);
     void setRxModeEnableWhenMCUSleep(void);
     void setLNAEnable(bool enabled);
-    bool isLnaCanControl(void) { return lna_can_control; }
+    bool isLnaCanControl(void) const { return lna_can_control; }
     void setLnaCanControl(bool can_control) { lna_can_control = can_control; }
+    bool isLNAEnabled(void) const { return lna_enabled; }
     LoRaFEMType getFEMType(void) const { return fem_type; }
   private:
     LoRaFEMType fem_type=OTHER_FEM_TYPES;

From 65752fef72191293d8c548d6ba6826663fe947b6 Mon Sep 17 00:00:00 2001
From: Quency-D <hj_zzns@163.com>
Date: Tue, 24 Mar 2026 13:57:11 +0800
Subject: [PATCH 02/23] Fix the memory leak issue in the strdup function.

---
 examples/simple_repeater/UITask.cpp    | 3 ++-
 examples/simple_room_server/UITask.cpp | 3 ++-
 examples/simple_sensor/UITask.cpp      | 3 ++-
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/examples/simple_repeater/UITask.cpp b/examples/simple_repeater/UITask.cpp
index d096d14b..d1eae208 100644
--- a/examples/simple_repeater/UITask.cpp
+++ b/examples/simple_repeater/UITask.cpp
@@ -37,7 +37,8 @@ void UITask::begin(NodePrefs* node_prefs, const char* build_date, const char* fi
   }
 
   // v1.2.3 (1 Jan 2025)
-  sprintf(_version_info, "%s (%s)", version, build_date);
+  snprintf(_version_info, sizeof(_version_info), "%s (%s)", version, build_date);
+  free(version);
 }
 
 void UITask::renderCurrScreen() {
diff --git a/examples/simple_room_server/UITask.cpp b/examples/simple_room_server/UITask.cpp
index 46311c5e..a48cc6b3 100644
--- a/examples/simple_room_server/UITask.cpp
+++ b/examples/simple_room_server/UITask.cpp
@@ -37,7 +37,8 @@ void UITask::begin(NodePrefs* node_prefs, const char* build_date, const char* fi
   }
 
   // v1.2.3 (1 Jan 2025)
-  sprintf(_version_info, "%s (%s)", version, build_date);
+  snprintf(_version_info, sizeof(_version_info), "%s (%s)", version, build_date);
+  free(version);
 }
 
 void UITask::renderCurrScreen() {
diff --git a/examples/simple_sensor/UITask.cpp b/examples/simple_sensor/UITask.cpp
index 0694bc3c..e16c8266 100644
--- a/examples/simple_sensor/UITask.cpp
+++ b/examples/simple_sensor/UITask.cpp
@@ -37,7 +37,8 @@ void UITask::begin(NodePrefs* node_prefs, const char* build_date, const char* fi
   }
 
   // v1.2.3 (1 Jan 2025)
-  sprintf(_version_info, "%s (%s)", version, build_date);
+  snprintf(_version_info, sizeof(_version_info), "%s (%s)", version, build_date);
+  free(version);
 }
 
 void UITask::renderCurrScreen() {

From 2442e9a5bd97fe29830164dd57208b98212d442e Mon Sep 17 00:00:00 2001
From: Quency-D <hj_zzns@163.com>
Date: Tue, 24 Mar 2026 16:05:28 +0800
Subject: [PATCH 03/23] Adapt LNA CLI control commands for heltec_tracker_v2.

---
 .../heltec_tracker_v2/HeltecTrackerV2Board.cpp | 18 ++++++++++++++++++
 .../heltec_tracker_v2/HeltecTrackerV2Board.h   |  3 +++
 variants/heltec_tracker_v2/LoRaFEMControl.h    |  3 ++-
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/variants/heltec_tracker_v2/HeltecTrackerV2Board.cpp b/variants/heltec_tracker_v2/HeltecTrackerV2Board.cpp
index aabfed79..f182c905 100644
--- a/variants/heltec_tracker_v2/HeltecTrackerV2Board.cpp
+++ b/variants/heltec_tracker_v2/HeltecTrackerV2Board.cpp
@@ -82,3 +82,21 @@ void HeltecTrackerV2Board::begin() {
   const char* HeltecTrackerV2Board::getManufacturerName() const {
     return "Heltec Tracker V2";
   }
+
+  bool HeltecTrackerV2Board::setLoRaFemLnaEnabled(bool enable) {
+    if (!loRaFEMControl.isLnaCanControl()) {
+      return false;
+    }
+
+    loRaFEMControl.setLNAEnable(enable);
+    loRaFEMControl.setRxModeEnable();
+    return true;
+  }
+
+  bool HeltecTrackerV2Board::canControlLoRaFemLna() const {
+    return loRaFEMControl.isLnaCanControl();
+  }
+
+  bool HeltecTrackerV2Board::isLoRaFemLnaEnabled() const {
+    return loRaFEMControl.isLNAEnabled();
+  }
diff --git a/variants/heltec_tracker_v2/HeltecTrackerV2Board.h b/variants/heltec_tracker_v2/HeltecTrackerV2Board.h
index 33c897bc..ccbecc7a 100644
--- a/variants/heltec_tracker_v2/HeltecTrackerV2Board.h
+++ b/variants/heltec_tracker_v2/HeltecTrackerV2Board.h
@@ -21,5 +21,8 @@ public:
   void powerOff() override;
   uint16_t getBattMilliVolts() override;
   const char* getManufacturerName() const override ;
+  bool setLoRaFemLnaEnabled(bool enable) override;
+  bool canControlLoRaFemLna() const override;
+  bool isLoRaFemLnaEnabled() const override;
 
 };
diff --git a/variants/heltec_tracker_v2/LoRaFEMControl.h b/variants/heltec_tracker_v2/LoRaFEMControl.h
index 2c50b742..0ce60fff 100644
--- a/variants/heltec_tracker_v2/LoRaFEMControl.h
+++ b/variants/heltec_tracker_v2/LoRaFEMControl.h
@@ -12,8 +12,9 @@ class LoRaFEMControl
     void setRxModeEnable(void);
     void setRxModeEnableWhenMCUSleep(void);
     void setLNAEnable(bool enabled);
-    bool isLnaCanControl(void) { return lna_can_control; }
+    bool isLnaCanControl(void) const { return lna_can_control; }
     void setLnaCanControl(bool can_control) { lna_can_control = can_control; }
+    bool isLNAEnabled(void) const { return lna_enabled; }
 
   private:
     bool lna_enabled = false;

From 9664305a872e5d7f52cb4f967dd35935a7423312 Mon Sep 17 00:00:00 2001
From: Quency-D <hj_zzns@163.com>
Date: Tue, 24 Mar 2026 16:13:13 +0800
Subject: [PATCH 04/23] Adapt LNA CLI control commands for heltec_t096.

---
 variants/heltec_t096/LoRaFEMControl.h |  3 ++-
 variants/heltec_t096/T096Board.cpp    | 20 +++++++++++++++++++-
 variants/heltec_t096/T096Board.h      |  3 +++
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/variants/heltec_t096/LoRaFEMControl.h b/variants/heltec_t096/LoRaFEMControl.h
index 2c50b742..0ce60fff 100644
--- a/variants/heltec_t096/LoRaFEMControl.h
+++ b/variants/heltec_t096/LoRaFEMControl.h
@@ -12,8 +12,9 @@ class LoRaFEMControl
     void setRxModeEnable(void);
     void setRxModeEnableWhenMCUSleep(void);
     void setLNAEnable(bool enabled);
-    bool isLnaCanControl(void) { return lna_can_control; }
+    bool isLnaCanControl(void) const { return lna_can_control; }
     void setLnaCanControl(bool can_control) { lna_can_control = can_control; }
+    bool isLNAEnabled(void) const { return lna_enabled; }
 
   private:
     bool lna_enabled = false;
diff --git a/variants/heltec_t096/T096Board.cpp b/variants/heltec_t096/T096Board.cpp
index 55013157..54425145 100644
--- a/variants/heltec_t096/T096Board.cpp
+++ b/variants/heltec_t096/T096Board.cpp
@@ -123,4 +123,22 @@ void T096Board::powerOff() {
 
 const char* T096Board::getManufacturerName() const {
   return "Heltec T096";
-}
\ No newline at end of file
+}
+
+bool T096Board::setLoRaFemLnaEnabled(bool enable) {
+  if (!loRaFEMControl.isLnaCanControl()) {
+    return false;
+  }
+
+  loRaFEMControl.setLNAEnable(enable);
+  loRaFEMControl.setRxModeEnable();
+  return true;
+}
+
+bool T096Board::canControlLoRaFemLna() const {
+  return loRaFEMControl.isLnaCanControl();
+}
+
+bool T096Board::isLoRaFemLnaEnabled() const {
+  return loRaFEMControl.isLNAEnabled();
+}
diff --git a/variants/heltec_t096/T096Board.h b/variants/heltec_t096/T096Board.h
index d1e3bdfd..15c7e68b 100644
--- a/variants/heltec_t096/T096Board.h
+++ b/variants/heltec_t096/T096Board.h
@@ -25,4 +25,7 @@ public:
   uint16_t getBattMilliVolts() override;
   const char* getManufacturerName() const override ;
   void powerOff() override;
+  bool setLoRaFemLnaEnabled(bool enable) override;
+  bool canControlLoRaFemLna() const override;
+  bool isLoRaFemLnaEnabled() const override;
 };

From 22f07b3e4871bfde1e8013b25155988694721a04 Mon Sep 17 00:00:00 2001
From: Quency-D <hj_zzns@163.com>
Date: Sat, 25 Apr 2026 15:33:59 +0800
Subject: [PATCH 05/23] Revert "Merge branch 'meshcore-dev:main' into
 cli-lna-command"

This reverts commit ca047fe0c05315ed77e64cfd72ee7a17b810a929, reversing
changes made to ddedb3c7a776f3f075d0bde2123b1c6f31186b90.
---
 README.md   | 2 +-
 docs/faq.md | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index f8b9e5e0..ebad1f6f 100644
--- a/README.md
+++ b/README.md
@@ -117,4 +117,4 @@ There are a number of fairly major features in the pipeline, with no particular
 
 - Report bugs and request features on the [GitHub Issues](https://github.com/ripplebiz/MeshCore/issues) page.
 - Find additional guides and components on [my site](https://buymeacoffee.com/ripplebiz).
-- Join [MeshCore Discord](https://meshcore.gg) to chat with the developers and get help from the community.
+- Join [MeshCore Discord](https://discord.gg/BMwCtwHj5V) to chat with the developers and get help from the community.
diff --git a/docs/faq.md b/docs/faq.md
index 3edc0a69..9fe1534a 100644
--- a/docs/faq.md
+++ b/docs/faq.md
@@ -194,7 +194,7 @@ Recently, as of October 2025, many regions have moved to the "narrow" setting, a
 
 After extensive testing, many regions have switched or about to switch over to BW62.5 and SF7, 8, or 9.  Narrower bandwidth setting and lower SF setting allow MeshCore's radio signals to fit between interference in the ISM band, provide for a lower noise floor, better SNR, and faster transmissions.
 
-If you have consensus from your community in your region to update your region's preset recommendation, please post your update request on  the [#meshcore-app](https://discord.com/channels/1343693475589263471/1391681655911088241) channel on the [MeshCore Discord server ](https://meshcore.gg) to let Liam Cottle know.
+If you have consensus from your community in your region to update your region's preset recommendation, please post your update request on  the [#meshcore-app](https://discord.com/channels/1343693475589263471/1391681655911088241) channel on the [MeshCore Discord server ](https://discord.gg/cYtQNYCCRK) to let Liam Cottle know.
 
 
 
@@ -526,7 +526,7 @@ The third character is the capital letter 'O', not zero `0`
 - Firmware repo: https://github.com/meshcore-dev/MeshCore
 
 ### 5.8. Q: How can I support MeshCore?
-**A:** Provide your honest feedback on GitHub and on [MeshCore Discord server](https://meshcore.gg). Spread the word of MeshCore to your friends and communities; help them get started with MeshCore. Support Scott's MeshCore development at <https://buymeacoffee.com/ripplebiz>.
+**A:** Provide your honest feedback on GitHub and on [MeshCore Discord server](https://discord.gg/BMwCtwHj5V). Spread the word of MeshCore to your friends and communities; help them get started with MeshCore. Support Scott's MeshCore development at <https://buymeacoffee.com/ripplebiz>.
 
 Support Liam Cottle's smartphone client development by unlocking the server administration wait gate with in-app purchase
 

From c42f6db0ebf53f821c4161e54a444ddaa4dd22b4 Mon Sep 17 00:00:00 2001
From: Quency-D <hj_zzns@163.com>
Date: Sat, 25 Apr 2026 16:01:26 +0800
Subject: [PATCH 06/23] Revise according to the review comments.

Co-authored-by: Copilot <copilot@github.com>
---
 examples/companion_radio/MyMesh.cpp | 11 ++++++-----
 src/helpers/CommonCLI.cpp           | 10 +++++-----
 variants/heltec_v4/HeltecV4Board.h  |  1 -
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index 91da9bcc..e98a7873 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -46,8 +46,7 @@
 #define CMD_SET_CUSTOM_VAR            41
 #define CMD_GET_ADVERT_PATH           42
 #define CMD_GET_TUNING_PARAMS         43
-#define CMD_GET_RADIO_FEM_RXGAIN      44
-#define CMD_SET_RADIO_FEM_RXGAIN      45
+
 // NOTE: CMD range 46..49 parked, potentially for WiFi operations
 #define CMD_SEND_BINARY_REQ           50
 #define CMD_FACTORY_RESET             51
@@ -63,6 +62,8 @@
 #define CMD_SEND_CHANNEL_DATA         62
 #define CMD_SET_DEFAULT_FLOOD_SCOPE   63
 #define CMD_GET_DEFAULT_FLOOD_SCOPE   64
+#define CMD_GET_RADIO_FEM_RXGAIN      65
+#define CMD_SET_RADIO_FEM_RXGAIN      66
 
 // Stats sub-types for CMD_GET_STATS
 #define STATS_TYPE_CORE               0
@@ -1808,9 +1809,9 @@ void MyMesh::handleCmdFrame(size_t len) {
       writeErrFrame(ERR_CODE_UNSUPPORTED_CMD);
     } else {
       out_frame[0] = RESP_CODE_OK;
-      uint32_t value = board.isLoRaFemLnaEnabled() ? 1 : 0;
-      memcpy(&out_frame[1], &value, 4);
-      _serial->writeFrame(out_frame, 5);
+      uint8_t value = board.isLoRaFemLnaEnabled() ? 1 : 0;
+      memcpy(&out_frame[1], &value, 1);
+      _serial->writeFrame(out_frame, 2);
     }
   } else if (cmd_frame[0] == CMD_SET_RADIO_FEM_RXGAIN && len >= 2) {
     uint8_t value = cmd_frame[1];
diff --git a/src/helpers/CommonCLI.cpp b/src/helpers/CommonCLI.cpp
index b9152f4c..d22e08a8 100644
--- a/src/helpers/CommonCLI.cpp
+++ b/src/helpers/CommonCLI.cpp
@@ -559,7 +559,7 @@ void CommonCLI::handleSetCmd(uint32_t sender_timestamp, char* command, char* rep
 #endif
   } else if (memcmp(config, "radio.fem.rxgain ", 17) == 0) {
     if (!_board->canControlLoRaFemLna()) {
-      strcpy(reply, "Error: unsupported by this board");
+      strcpy(reply, "Error: unsupported");
     } else if (memcmp(&config[17], "on", 2) == 0) {
       if (_board->setLoRaFemLnaEnabled(true)) {
         _prefs->radio_fem_rxgain = 1;
@@ -750,7 +750,7 @@ void CommonCLI::handleSetCmd(uint32_t sender_timestamp, char* command, char* rep
       }
     } else {
       _prefs->adc_multiplier = 0.0f;
-      strcpy(reply, "Error: unsupported by this board");
+      strcpy(reply, "Error: unsupported");
     };
   } else {
     strcpy(reply, "unknown config: ");
@@ -800,7 +800,7 @@ void CommonCLI::handleGetCmd(uint32_t sender_timestamp, char* command, char* rep
 #endif
   } else if (memcmp(config, "radio.fem.rxgain", 16) == 0) {
     if (!_board->canControlLoRaFemLna()) {
-      strcpy(reply, "Error: unsupported by this board");
+      strcpy(reply, "Error: unsupported");
     } else {
       sprintf(reply, "> %s", _board->isLoRaFemLnaEnabled() ? "on" : "off");
     }
@@ -885,12 +885,12 @@ void CommonCLI::handleGetCmd(uint32_t sender_timestamp, char* command, char* rep
           strcpy(reply, "> unknown");
       }
   #else
-      strcpy(reply, "ERROR: unsupported");
+      strcpy(reply, "Error: unsupported");
   #endif
   } else if (memcmp(config, "adc.multiplier", 14) == 0) {
     float adc_mult = _board->getAdcMultiplier();
     if (adc_mult == 0.0f) {
-      strcpy(reply, "Error: unsupported by this board");
+      strcpy(reply, "Error: unsupported");
     } else {
       sprintf(reply, "> %.3f", adc_mult);
     }
diff --git a/variants/heltec_v4/HeltecV4Board.h b/variants/heltec_v4/HeltecV4Board.h
index b2caaa35..fc37b9f6 100644
--- a/variants/heltec_v4/HeltecV4Board.h
+++ b/variants/heltec_v4/HeltecV4Board.h
@@ -25,7 +25,6 @@ public:
   void onAfterTransmit(void) override;
   void enterDeepSleep(uint32_t secs, int pin_wake_btn = -1);
   void powerOff() override;
-  const char* getManufacturerName() const override ;
   bool setLoRaFemLnaEnabled(bool enable) override;
   bool canControlLoRaFemLna() const override;
   bool isLoRaFemLnaEnabled() const override;

From 9d26953398d75c1c57c5c818957b5384e86921e8 Mon Sep 17 00:00:00 2001
From: Quency-D <55523105+Quency-D@users.noreply.github.com>
Date: Sat, 25 Apr 2026 16:10:57 +0800
Subject: [PATCH 07/23] Remove unnecessary blank line in MyMesh.cpp

---
 examples/companion_radio/MyMesh.cpp | 1 -
 1 file changed, 1 deletion(-)

diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index e98a7873..1b664eea 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -46,7 +46,6 @@
 #define CMD_SET_CUSTOM_VAR            41
 #define CMD_GET_ADVERT_PATH           42
 #define CMD_GET_TUNING_PARAMS         43
-
 // NOTE: CMD range 46..49 parked, potentially for WiFi operations
 #define CMD_SEND_BINARY_REQ           50
 #define CMD_FACTORY_RESET             51

From 62b0d82682ec9cf51c0e8f08aa835a6c8bf6aefc Mon Sep 17 00:00:00 2001
From: Quency-D <55523105+Quency-D@users.noreply.github.com>
Date: Sat, 25 Apr 2026 16:12:40 +0800
Subject: [PATCH 08/23] Restore WiFi operation command scope comments

---
 examples/companion_radio/MyMesh.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index 1b664eea..2d1f6dcd 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -46,7 +46,7 @@
 #define CMD_SET_CUSTOM_VAR            41
 #define CMD_GET_ADVERT_PATH           42
 #define CMD_GET_TUNING_PARAMS         43
-// NOTE: CMD range 46..49 parked, potentially for WiFi operations
+// NOTE: CMD range 44..49 parked, potentially for WiFi operations
 #define CMD_SEND_BINARY_REQ           50
 #define CMD_FACTORY_RESET             51
 #define CMD_SEND_PATH_DISCOVERY_REQ   52

From 444dcfb8fd564fb10a131aa75415d41f7f66107c Mon Sep 17 00:00:00 2001
From: Quency-D <55523105+Quency-D@users.noreply.github.com>
Date: Mon, 27 Apr 2026 14:06:21 +0800
Subject: [PATCH 09/23] Change write to read for radio_fem_rxgain

---
 examples/companion_radio/DataStore.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/companion_radio/DataStore.cpp b/examples/companion_radio/DataStore.cpp
index f1dc678e..362ba68a 100644
--- a/examples/companion_radio/DataStore.cpp
+++ b/examples/companion_radio/DataStore.cpp
@@ -233,7 +233,7 @@ void DataStore::loadPrefsInt(const char *filename, NodePrefs& _prefs, double& no
     file.read((uint8_t *)&_prefs.rx_boosted_gain, sizeof(_prefs.rx_boosted_gain));         // 89
     file.read((uint8_t *)_prefs.default_scope_name, sizeof(_prefs.default_scope_name));    // 90
     file.read((uint8_t *)_prefs.default_scope_key, sizeof(_prefs.default_scope_key));     // 121
-    file.write((uint8_t *)&_prefs.radio_fem_rxgain, sizeof(_prefs.radio_fem_rxgain));      // 122
+    file.read((uint8_t *)&_prefs.radio_fem_rxgain, sizeof(_prefs.radio_fem_rxgain));      // 122
 
     file.close();
   }

From 07bfe9069565729205d79edf4cd2a0071b22fe3f Mon Sep 17 00:00:00 2001
From: liamcottle <liam@liamcottle.com>
Date: Tue, 9 Jun 2026 00:31:48 +1200
Subject: [PATCH 10/23] free packet on parse failure

---
 examples/companion_radio/MyMesh.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index 6fbb0f74..07353988 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -1981,6 +1981,7 @@ void MyMesh::handleCmdFrame(size_t len) {
         sendPacket(pkt, priority, 0);
         writeOKFrame();
       } else {
+        _mgr->free(pkt);
         writeErrFrame(ERR_CODE_ILLEGAL_ARG);
       }
     } else {

From ae0bb7ee9544db0a0eb05ce7405432cb8ed6496a Mon Sep 17 00:00:00 2001
From: liamcottle <liam@liamcottle.com>
Date: Tue, 9 Jun 2026 00:42:58 +1200
Subject: [PATCH 11/23] use releasePacket instead of _mgr->free

---
 examples/companion_radio/MyMesh.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index 07353988..c468967f 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -1981,7 +1981,7 @@ void MyMesh::handleCmdFrame(size_t len) {
         sendPacket(pkt, priority, 0);
         writeOKFrame();
       } else {
-        _mgr->free(pkt);
+        releasePacket(pkt);
         writeErrFrame(ERR_CODE_ILLEGAL_ARG);
       }
     } else {

From d5f74e93c530a41a2c88dbcc5f34f06860129179 Mon Sep 17 00:00:00 2001
From: Scott Powell <ripple_biz@protonmail.com>
Date: Sat, 13 Jun 2026 18:19:41 +1000
Subject: [PATCH 12/23] * PAYLOAD_TYPE_PATH bad path_len now rejected

---
 src/Mesh.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/Mesh.cpp b/src/Mesh.cpp
index 87ad61af..e9b92262 100644
--- a/src/Mesh.cpp
+++ b/src/Mesh.cpp
@@ -155,6 +155,10 @@ DispatcherAction Mesh::onRecvPacket(Packet* pkt) {
               if (pkt->getPayloadType() == PAYLOAD_TYPE_PATH) {
                 int k = 0;
                 uint8_t path_len = data[k++];
+                if (!Packet::isValidPathLen(path_len)) {
+                  MESH_DEBUG_PRINTLN("%s PAYLOAD_TYPE_PATH, bad path_len: %u", getLogDateTime(), (uint32_t)path_len);
+                  break;   // reject bad encoding
+                }
                 uint8_t hash_size = (path_len >> 6) + 1;
                 uint8_t hash_count = path_len & 63;
                 uint8_t* path = &data[k]; k += hash_size*hash_count;

From 3ee58fd2e3f16cad205611503b6dd71728aac23c Mon Sep 17 00:00:00 2001
From: Quency-D <hj_zzns@163.com>
Date: Sat, 13 Jun 2026 17:31:54 +0800
Subject: [PATCH 13/23] Remove companion FEM RX gain command IDs

---
 examples/companion_radio/DataStore.cpp |  2 --
 examples/companion_radio/MyMesh.cpp    | 29 --------------------------
 examples/companion_radio/NodePrefs.h   |  1 -
 3 files changed, 32 deletions(-)

diff --git a/examples/companion_radio/DataStore.cpp b/examples/companion_radio/DataStore.cpp
index fdb924ad..bf2f36c3 100644
--- a/examples/companion_radio/DataStore.cpp
+++ b/examples/companion_radio/DataStore.cpp
@@ -233,7 +233,6 @@ void DataStore::loadPrefsInt(const char *filename, NodePrefs& _prefs, double& no
     file.read((uint8_t *)&_prefs.rx_boosted_gain, sizeof(_prefs.rx_boosted_gain));         // 89
     file.read((uint8_t *)_prefs.default_scope_name, sizeof(_prefs.default_scope_name));    // 90
     file.read((uint8_t *)_prefs.default_scope_key, sizeof(_prefs.default_scope_key));     // 121
-    file.read((uint8_t *)&_prefs.radio_fem_rxgain, sizeof(_prefs.radio_fem_rxgain));      // 122
 
     file.close();
   }
@@ -274,7 +273,6 @@ void DataStore::savePrefs(const NodePrefs& _prefs, double node_lat, double node_
     file.write((uint8_t *)&_prefs.rx_boosted_gain, sizeof(_prefs.rx_boosted_gain));         // 89
     file.write((uint8_t *)_prefs.default_scope_name, sizeof(_prefs.default_scope_name));    // 90
     file.write((uint8_t *)_prefs.default_scope_key, sizeof(_prefs.default_scope_key));     // 121
-    file.write((uint8_t *)&_prefs.radio_fem_rxgain, sizeof(_prefs.radio_fem_rxgain));      // 122
 
     file.close();
   }
diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index 1dd5162b..c468967f 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -62,8 +62,6 @@
 #define CMD_SET_DEFAULT_FLOOD_SCOPE   63
 #define CMD_GET_DEFAULT_FLOOD_SCOPE   64
 #define CMD_SEND_RAW_PACKET           65
-#define CMD_GET_RADIO_FEM_RXGAIN      66
-#define CMD_SET_RADIO_FEM_RXGAIN      67
 
 // Stats sub-types for CMD_GET_STATS
 #define STATS_TYPE_CORE               0
@@ -888,7 +886,6 @@ MyMesh::MyMesh(mesh::Radio &radio, mesh::RNG &rng, mesh::RTCClock &rtc, SimpleMe
   _prefs.rx_boosted_gain = 1; // enabled by default
 #endif
 #endif
-  _prefs.radio_fem_rxgain = 1;
 }
 
 void MyMesh::begin(bool has_display) {
@@ -938,7 +935,6 @@ void MyMesh::begin(bool has_display) {
   _prefs.tx_power_dbm = constrain(_prefs.tx_power_dbm, -9, MAX_LORA_TX_POWER);
   _prefs.gps_enabled = constrain(_prefs.gps_enabled, 0, 1);  // Ensure boolean 0 or 1
   _prefs.gps_interval = constrain(_prefs.gps_interval, 0, 86400);  // Max 24 hours
-  _prefs.radio_fem_rxgain = constrain(_prefs.radio_fem_rxgain, 0, 1);
 
 #ifdef BLE_PIN_CODE // 123456 by default
   if (_prefs.ble_pin == 0) {
@@ -968,7 +964,6 @@ void MyMesh::begin(bool has_display) {
   radio_driver.setParams(_prefs.freq, _prefs.bw, _prefs.sf, _prefs.cr);
   radio_driver.setTxPower(_prefs.tx_power_dbm);
   radio_driver.setRxBoostedGainMode(_prefs.rx_boosted_gain);
-  board.setLoRaFemLnaEnabled(_prefs.radio_fem_rxgain);
   MESH_DEBUG_PRINTLN("RX Boosted Gain Mode: %s",
                      radio_driver.getRxBoostedGainMode() ? "Enabled" : "Disabled");
 }
@@ -1826,30 +1821,6 @@ void MyMesh::handleCmdFrame(size_t len) {
     } else {
       writeErrFrame(ERR_CODE_ILLEGAL_ARG);
     }
-  } else if (cmd_frame[0] == CMD_GET_RADIO_FEM_RXGAIN) {
-    if (!board.canControlLoRaFemLna()) {
-      writeErrFrame(ERR_CODE_UNSUPPORTED_CMD);
-    } else {
-      out_frame[0] = RESP_CODE_OK;
-      uint8_t value = board.isLoRaFemLnaEnabled() ? 1 : 0;
-      memcpy(&out_frame[1], &value, 1);
-      _serial->writeFrame(out_frame, 2);
-    }
-  } else if (cmd_frame[0] == CMD_SET_RADIO_FEM_RXGAIN && len >= 2) {
-    uint8_t value = cmd_frame[1];
-    if (!board.canControlLoRaFemLna()) {
-      writeErrFrame(ERR_CODE_UNSUPPORTED_CMD);
-    } else if (value <= 1) {
-      _prefs.radio_fem_rxgain = value;
-      if (board.setLoRaFemLnaEnabled(value != 0)) {
-        savePrefs();
-        writeOKFrame();
-      } else {
-        writeErrFrame(ERR_CODE_UNSUPPORTED_CMD);
-      }
-    } else {
-      writeErrFrame(ERR_CODE_ILLEGAL_ARG);
-    }
   } else if (cmd_frame[0] == CMD_GET_ADVERT_PATH && len >= PUB_KEY_SIZE+2) {
     // FUTURE use:  uint8_t reserved = cmd_frame[1];
     uint8_t *pub_key = &cmd_frame[2];
diff --git a/examples/companion_radio/NodePrefs.h b/examples/companion_radio/NodePrefs.h
index ecb117bd..84d51413 100644
--- a/examples/companion_radio/NodePrefs.h
+++ b/examples/companion_radio/NodePrefs.h
@@ -29,7 +29,6 @@ struct NodePrefs {  // persisted to file
   uint32_t gps_interval;     // GPS read interval in seconds
   uint8_t autoadd_config;    // bitmask for auto-add contacts config
   uint8_t rx_boosted_gain; // SX126x RX boosted gain mode (0=power saving, 1=boosted)
-  uint8_t radio_fem_rxgain;  // LoRa FEM RX gain setting
   uint8_t client_repeat;
   uint8_t path_hash_mode;    // which path mode to use when sending
   uint8_t autoadd_max_hops;  // 0 = no limit, 1 = direct (0 hops), N = up to N-1 hops (max 64)

From 5300fa18c7b0f441d9a123b86aa49a7a5c9739cf Mon Sep 17 00:00:00 2001
From: Quency-D <hj_zzns@163.com>
Date: Sat, 13 Jun 2026 17:40:11 +0800
Subject: [PATCH 14/23] Restore companion NodePrefs file ending

---
 examples/companion_radio/NodePrefs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/companion_radio/NodePrefs.h b/examples/companion_radio/NodePrefs.h
index 84d51413..48c381ce 100644
--- a/examples/companion_radio/NodePrefs.h
+++ b/examples/companion_radio/NodePrefs.h
@@ -34,4 +34,4 @@ struct NodePrefs {  // persisted to file
   uint8_t autoadd_max_hops;  // 0 = no limit, 1 = direct (0 hops), N = up to N-1 hops (max 64)
   char default_scope_name[31];
   uint8_t default_scope_key[16];
-};
+};
\ No newline at end of file

From 07648e3344780bcac297d197ec1579a91a308fbf Mon Sep 17 00:00:00 2001
From: Scott Powell <ripple_biz@protonmail.com>
Date: Sun, 14 Jun 2026 17:50:41 +1000
Subject: [PATCH 15/23] * fix for anon contacts when full

---
 examples/companion_radio/MyMesh.cpp  | 12 ++------
 examples/simple_secure_chat/main.cpp |  2 +-
 src/helpers/BaseChatMesh.cpp         | 45 ++++++++++++++++------------
 src/helpers/BaseChatMesh.h           | 14 ++++++---
 4 files changed, 39 insertions(+), 34 deletions(-)

diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index c468967f..d05bc6de 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -854,7 +854,7 @@ void MyMesh::onSendTimeout() {}
 
 MyMesh::MyMesh(mesh::Radio &radio, mesh::RNG &rng, mesh::RTCClock &rtc, SimpleMeshTables &tables, DataStore& store, AbstractUITask* ui)
     : BaseChatMesh(radio, *new ArduinoMillis(), rng, rtc, *new StaticPoolPacketManager(16), tables),
-      _serial(NULL), telemetry(MAX_PACKET_PAYLOAD - 4), _store(&store), _ui(ui) {
+      _serial(NULL), telemetry(MAX_PACKET_PAYLOAD - 4), _store(&store), _ui(ui), _iter(0) {
   _iter_started = false;
   _cli_rescue = false;
   offline_queue_len = 0;
@@ -2187,15 +2187,7 @@ void MyMesh::checkSerialInterface() {
              && !_serial->isWriteBusy() // don't spam the Serial Interface too quickly!
   ) {
     ContactInfo contact;
-    bool found = false;
-    while (_iter.hasNext(this, contact)) {
-      if (contact.type != ADV_TYPE_NONE) {
-        found = true;
-        break;
-      }
-    }
-
-    if (found) {
+    if (_iter.hasNext(this, contact)) {
       if (contact.lastmod > _iter_filter_since) { // apply the 'since' filter
         writeContactRespFrame(RESP_CODE_CONTACT, contact);
         if (contact.lastmod > _most_recent_lastmod) {
diff --git a/examples/simple_secure_chat/main.cpp b/examples/simple_secure_chat/main.cpp
index d5066736..d93810ed 100644
--- a/examples/simple_secure_chat/main.cpp
+++ b/examples/simple_secure_chat/main.cpp
@@ -135,7 +135,7 @@ class MyMesh : public BaseChatMesh, ContactVisitor {
     File file = _fs->open("/contacts", "w", true);
 #endif
     if (file) {
-      ContactsIterator iter;
+      ContactsIterator iter = startContactsIterator();
       ContactInfo c;
       uint8_t unused = 0;
       uint32_t reserved = 0;
diff --git a/src/helpers/BaseChatMesh.cpp b/src/helpers/BaseChatMesh.cpp
index d3ef034e..71b2681f 100644
--- a/src/helpers/BaseChatMesh.cpp
+++ b/src/helpers/BaseChatMesh.cpp
@@ -68,29 +68,36 @@ void BaseChatMesh::bootstrapRTCfromContacts() {
 }
 
 ContactInfo* BaseChatMesh::allocateContactSlot(bool transient_only) {
-  if (num_contacts < MAX_CONTACTS) {
-    return &contacts[num_contacts++];
-  } else if (transient_only || shouldOverwriteWhenFull()) {
-    // Find oldest non-favourite contact by oldest lastmod timestamp
-    int oldest_idx = -1;
-    uint32_t oldest_lastmod = 0xFFFFFFFF;
-    for (int i = 0; i < num_contacts; i++) {
-      if (transient_only) {
-        if (contacts[i].type == ADV_TYPE_NONE && contacts[i].lastmod < oldest_lastmod) {
-          oldest_lastmod = contacts[i].lastmod;
-          oldest_idx = i;
-        }
-      } else {
+  int oldest_idx = -1;
+  uint32_t oldest_lastmod = 0xFFFFFFFF;
+  if (transient_only) {
+    // only allocate from first N
+    for (int i = 0; i < MAX_ANON_CONTACTS; i++) {
+      if (contacts[i].type == ADV_TYPE_NONE && contacts[i].lastmod < oldest_lastmod) {
+        oldest_lastmod = contacts[i].lastmod;
+        oldest_idx = i;
+      }
+    }
+    if (oldest_idx >= 0) {
+      // NOTE: do NOT call onContactOverwrite()
+      return &contacts[oldest_idx];
+    }
+  } else {
+    if (num_contacts < MAX_ANON_CONTACTS+MAX_CONTACTS) {
+      return &contacts[num_contacts++];
+    } else if (shouldOverwriteWhenFull()) {
+      // Find oldest non-favourite contact by oldest lastmod timestamp
+      for (int i = MAX_ANON_CONTACTS; i < num_contacts; i++) {
         bool is_favourite = (contacts[i].flags & 0x01) != 0;
-        if (!is_favourite && contacts[i].lastmod < oldest_lastmod && contacts[i].type != ADV_TYPE_NONE) {
+        if (!is_favourite && contacts[i].lastmod < oldest_lastmod) {
           oldest_lastmod = contacts[i].lastmod;
           oldest_idx = i;
         }
       }
-    }
-    if (oldest_idx >= 0) {
-      onContactOverwrite(contacts[oldest_idx].id.pub_key);
-      return &contacts[oldest_idx];
+      if (oldest_idx >= 0) {
+        onContactOverwrite(contacts[oldest_idx].id.pub_key);
+        return &contacts[oldest_idx];
+      }
     }
   }
   return NULL; // no space, no overwrite or all contacts are all favourites
@@ -930,7 +937,7 @@ bool BaseChatMesh::getContactByIdx(uint32_t idx, ContactInfo& contact) {
 }
 
 ContactsIterator BaseChatMesh::startContactsIterator() {
-  return ContactsIterator();
+  return ContactsIterator(MAX_ANON_CONTACTS);   // start at offset, skip the anon entries
 }
 
 bool ContactsIterator::hasNext(const BaseChatMesh* mesh, ContactInfo& dest) {
diff --git a/src/helpers/BaseChatMesh.h b/src/helpers/BaseChatMesh.h
index c04bfda3..3a277c1e 100644
--- a/src/helpers/BaseChatMesh.h
+++ b/src/helpers/BaseChatMesh.h
@@ -28,8 +28,9 @@ public:
 class BaseChatMesh;
 
 class ContactsIterator {
-  int next_idx = 0;
+  int next_idx;
 public:
+  ContactsIterator(int start) { next_idx = start; }
   bool hasNext(const BaseChatMesh* mesh, ContactInfo& dest);
 };
 
@@ -79,8 +80,9 @@ class BaseChatMesh : public mesh::Mesh {
 protected:
   BaseChatMesh(mesh::Radio& radio, mesh::MillisecondClock& ms, mesh::RNG& rng, mesh::RTCClock& rtc, mesh::PacketManager& mgr, mesh::MeshTables& tables)
       : mesh::Mesh(radio, ms, rng, rtc, mgr, tables)
-  { 
-    num_contacts = 0;
+  {
+    resetContacts();
+
   #ifdef MAX_GROUP_CHANNELS
     memset(channels, 0, sizeof(channels));
     num_channels = 0;
@@ -91,7 +93,11 @@ protected:
   }
 
   void bootstrapRTCfromContacts();
-  void resetContacts() { num_contacts = 0; }
+
+  void resetContacts() {
+    memset(contacts, 0, sizeof(contacts[0])*MAX_ANON_CONTACTS);   // set all to have type = ADV_TYPE_NONE(0)
+    num_contacts = MAX_ANON_CONTACTS;  // seed the first contacts for anon requests
+  }
   void populateContactFromAdvert(ContactInfo& ci, const mesh::Identity& id, const AdvertDataParser& parser, uint32_t timestamp);
   ContactInfo* allocateContactSlot(bool transient_only=false); // helper to find slot for new contact
 

From c2d223ff5512f2862b004d33b8b39e9b8340cffe Mon Sep 17 00:00:00 2001
From: Scott Powell <ripple_biz@protonmail.com>
Date: Sun, 14 Jun 2026 18:12:08 +1000
Subject: [PATCH 16/23] * now handle the case where onAdvertRecv() should
 _replace_ the anon contact slot

---
 src/helpers/BaseChatMesh.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/helpers/BaseChatMesh.cpp b/src/helpers/BaseChatMesh.cpp
index 71b2681f..ef586303 100644
--- a/src/helpers/BaseChatMesh.cpp
+++ b/src/helpers/BaseChatMesh.cpp
@@ -146,6 +146,11 @@ void BaseChatMesh::onAdvertRecv(mesh::Packet* packet, const mesh::Identity& id,
     packet->header = save;
   }
 
+  if (from && from->type == ADV_TYPE_NONE) {   // already in contacts, but from a temporary ANON_REQ ?
+    memset(from, 0, sizeof(*from));  // clear the anon/temp slot
+    from = NULL;  // do normal 'add' flow
+  }
+
   bool is_new = false; // true = not in contacts[], false = exists in contacts[]
   if (from == NULL) {
     if (!shouldAutoAddContactType(parser.getType())) {

From 538ac38e18c87181b884b93d7045752999253c21 Mon Sep 17 00:00:00 2001
From: Scott Powell <ripple_biz@protonmail.com>
Date: Sun, 14 Jun 2026 18:39:34 +1000
Subject: [PATCH 17/23] * fix for counter in RESP_CODE_CONTACTS_START

---
 src/helpers/BaseChatMesh.cpp | 2 +-
 src/helpers/BaseChatMesh.h   | 3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/helpers/BaseChatMesh.cpp b/src/helpers/BaseChatMesh.cpp
index ef586303..972a97e9 100644
--- a/src/helpers/BaseChatMesh.cpp
+++ b/src/helpers/BaseChatMesh.cpp
@@ -946,7 +946,7 @@ ContactsIterator BaseChatMesh::startContactsIterator() {
 }
 
 bool ContactsIterator::hasNext(const BaseChatMesh* mesh, ContactInfo& dest) {
-  if (next_idx >= mesh->getNumContacts()) return false;
+  if (next_idx >= mesh->getTotalContactSlots()) return false;
 
   dest = mesh->contacts[next_idx++];
   return true;
diff --git a/src/helpers/BaseChatMesh.h b/src/helpers/BaseChatMesh.h
index 3a277c1e..d9878547 100644
--- a/src/helpers/BaseChatMesh.h
+++ b/src/helpers/BaseChatMesh.h
@@ -172,7 +172,8 @@ public:
   ContactInfo* lookupContactByPubKey(const uint8_t* pub_key, int prefix_len);
   bool  removeContact(ContactInfo& contact);
   bool  addContact(const ContactInfo& contact);
-  int getNumContacts() const { return num_contacts; }
+  int getTotalContactSlots() const { return num_contacts; }
+  int getNumContacts() const { return num_contacts - MAX_ANON_CONTACTS; }  // don't include the reserved slots at start
   bool getContactByIdx(uint32_t idx, ContactInfo& contact);
   ContactsIterator startContactsIterator();
   ChannelDetails* addChannel(const char* name, const char* psk_base64);

From 2e73fe948eca9e289f8dd8900a251b027e33a014 Mon Sep 17 00:00:00 2001
From: Scott Powell <ripple_biz@protonmail.com>
Date: Sun, 14 Jun 2026 18:54:51 +1000
Subject: [PATCH 18/23] * fix for anon lastmod

---
 examples/companion_radio/MyMesh.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index d05bc6de..0b90df8b 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -1542,6 +1542,7 @@ void MyMesh::handleCmdFrame(size_t len) {
       memcpy(anon.id.pub_key, pub_key, PUB_KEY_SIZE);
       anon.out_path_len = 0;   // default to zero-hop direct
       anon.type = ADV_TYPE_NONE;  // unknown
+      anon.lastmod = getRTCClock()->getCurrentTime();
 
       if (addContact(anon)) recipient = &anon;
     }

From 4f9a0916714baa2a34ef294289bff78809056676 Mon Sep 17 00:00:00 2001
From: Wessel Nieboer <wessel@weebl.me>
Date: Wed, 18 Feb 2026 01:16:52 +0100
Subject: [PATCH 19/23] Use hardware channel activity detection for checking
 interference

---
 examples/companion_radio/MyMesh.cpp       |  2 +-
 examples/simple_repeater/MyMesh.cpp       |  2 +-
 examples/simple_room_server/MyMesh.cpp    |  2 +-
 examples/simple_sensor/SensorMesh.cpp     |  2 +-
 src/helpers/radiolib/RadioLibWrappers.cpp | 13 ++++++++++---
 src/helpers/radiolib/RadioLibWrappers.h   |  3 ++-
 6 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index 0b90df8b..2433f595 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -259,7 +259,7 @@ float MyMesh::getAirtimeBudgetFactor() const {
 }
 
 int MyMesh::getInterferenceThreshold() const {
-  return 0; // disabled for now, until currentRSSI() problem is resolved
+  return 1; // non-zero enables hardware CAD (Channel Activity Detection) before TX
 }
 
 int MyMesh::calcRxDelay(float score, uint32_t air_time) const {
diff --git a/examples/simple_repeater/MyMesh.cpp b/examples/simple_repeater/MyMesh.cpp
index af4706c1..dd282ec8 100644
--- a/examples/simple_repeater/MyMesh.cpp
+++ b/examples/simple_repeater/MyMesh.cpp
@@ -892,7 +892,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.flood_max = 64;
   _prefs.flood_max_unscoped = 64;
   _prefs.flood_max_advert = 8;
-  _prefs.interference_threshold = 0; // disabled
+  _prefs.interference_threshold = 1; // non-zero enables hardware CAD before TX
 
   // bridge defaults
   _prefs.bridge_enabled = 1;    // enabled
diff --git a/examples/simple_room_server/MyMesh.cpp b/examples/simple_room_server/MyMesh.cpp
index 349efb44..97ec80ac 100644
--- a/examples/simple_room_server/MyMesh.cpp
+++ b/examples/simple_room_server/MyMesh.cpp
@@ -649,7 +649,7 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.flood_max = 64;
   _prefs.flood_max_unscoped = 64;
   _prefs.flood_max_advert = 8;
-  _prefs.interference_threshold = 0; // disabled
+  _prefs.interference_threshold = 1; // non-zero enables hardware CAD before TX
 #ifdef ROOM_PASSWORD
   StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
 #endif
diff --git a/examples/simple_sensor/SensorMesh.cpp b/examples/simple_sensor/SensorMesh.cpp
index c0235a14..2a2c7feb 100644
--- a/examples/simple_sensor/SensorMesh.cpp
+++ b/examples/simple_sensor/SensorMesh.cpp
@@ -725,7 +725,7 @@ SensorMesh::SensorMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::Millise
   _prefs.flood_advert_interval = 0;   // disabled
   _prefs.disable_fwd = true;
   _prefs.flood_max = 64;
-  _prefs.interference_threshold = 0;  // disabled
+  _prefs.interference_threshold = 1;  // non-zero enables hardware CAD before TX
 
   // GPS defaults
   _prefs.gps_enabled = 0;
diff --git a/src/helpers/radiolib/RadioLibWrappers.cpp b/src/helpers/radiolib/RadioLibWrappers.cpp
index b6519aef..c67ab768 100644
--- a/src/helpers/radiolib/RadioLibWrappers.cpp
+++ b/src/helpers/radiolib/RadioLibWrappers.cpp
@@ -178,10 +178,17 @@ void RadioLibWrapper::onSendFinished() {
   state = STATE_IDLE;
 }
 
+int16_t RadioLibWrapper::performChannelScan() {
+  return _radio->scanChannel();
+}
+
 bool RadioLibWrapper::isChannelActive() {
-  return _threshold == 0 
-          ? false    // interference check is disabled
-          : getCurrentRSSI() > _noise_floor + _threshold;
+  if (_threshold == 0) return false;    // interference check is disabled
+
+  int16_t result = performChannelScan();
+  // scanChannel() leaves radio in standby — restart RX regardless of result
+  startRecv();
+  return (result == RADIOLIB_LORA_DETECTED);
 }
 
 float RadioLibWrapper::getLastRSSI() const {
diff --git a/src/helpers/radiolib/RadioLibWrappers.h b/src/helpers/radiolib/RadioLibWrappers.h
index efd3e179..c1ece644 100644
--- a/src/helpers/radiolib/RadioLibWrappers.h
+++ b/src/helpers/radiolib/RadioLibWrappers.h
@@ -32,7 +32,7 @@ public:
   bool isInRecvMode() const override;
   bool isChannelActive();
 
-  bool isReceiving() override { 
+  bool isReceiving() override {
     if (isReceivingPacket()) return true;
 
     return isChannelActive();
@@ -46,6 +46,7 @@ public:
   virtual uint8_t getSpreadingFactor() const { return LORA_SF; }
   static uint16_t preambleLengthForSF(uint8_t sf) { return sf <= 8 ? 32 : 16; }
   void updatePreamble(uint8_t sf) { _preamble_sf = sf; _radio->setPreambleLength(preambleLengthForSF(sf)); }
+  virtual int16_t performChannelScan();
 
   int getNoiseFloor() const override { return _noise_floor; }
   void triggerNoiseFloorCalibrate(int threshold) override;

From 813d108c7ab26e0b8e55087081ff84b9d62e91ba Mon Sep 17 00:00:00 2001
From: Wessel Nieboer <github@weebl.me>
Date: Sun, 22 Feb 2026 16:05:18 +0100
Subject: [PATCH 20/23] Also return busy if preamble detected

---
 src/helpers/radiolib/RadioLibWrappers.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/helpers/radiolib/RadioLibWrappers.cpp b/src/helpers/radiolib/RadioLibWrappers.cpp
index c67ab768..9b00b176 100644
--- a/src/helpers/radiolib/RadioLibWrappers.cpp
+++ b/src/helpers/radiolib/RadioLibWrappers.cpp
@@ -188,7 +188,7 @@ bool RadioLibWrapper::isChannelActive() {
   int16_t result = performChannelScan();
   // scanChannel() leaves radio in standby — restart RX regardless of result
   startRecv();
-  return (result == RADIOLIB_LORA_DETECTED);
+  return (result == RADIOLIB_LORA_DETECTED || result == RADIOLIB_PREAMBLE_DETECTED);
 }
 
 float RadioLibWrapper::getLastRSSI() const {

From 04a6c7009ab26c3af2c2e1550c07201139235dc2 Mon Sep 17 00:00:00 2001
From: Wessel Nieboer <github@weebl.me>
Date: Sun, 22 Feb 2026 16:08:04 +0100
Subject: [PATCH 21/23] Just check for not channel free

---
 src/helpers/radiolib/RadioLibWrappers.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/helpers/radiolib/RadioLibWrappers.cpp b/src/helpers/radiolib/RadioLibWrappers.cpp
index 9b00b176..d50c2bac 100644
--- a/src/helpers/radiolib/RadioLibWrappers.cpp
+++ b/src/helpers/radiolib/RadioLibWrappers.cpp
@@ -188,7 +188,7 @@ bool RadioLibWrapper::isChannelActive() {
   int16_t result = performChannelScan();
   // scanChannel() leaves radio in standby — restart RX regardless of result
   startRecv();
-  return (result == RADIOLIB_LORA_DETECTED || result == RADIOLIB_PREAMBLE_DETECTED);
+  return result != RADIOLIB_CHANNEL_FREE;
 }
 
 float RadioLibWrapper::getLastRSSI() const {

From 099ef6734843261d5a542570d8d1c3f35dced36c Mon Sep 17 00:00:00 2001
From: Wessel Nieboer <github@weebl.me>
Date: Fri, 6 Mar 2026 04:09:05 +0100
Subject: [PATCH 22/23] Prevent packet errors from growing

---
 src/helpers/radiolib/RadioLibWrappers.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/helpers/radiolib/RadioLibWrappers.cpp b/src/helpers/radiolib/RadioLibWrappers.cpp
index d50c2bac..5d68d7e9 100644
--- a/src/helpers/radiolib/RadioLibWrappers.cpp
+++ b/src/helpers/radiolib/RadioLibWrappers.cpp
@@ -186,7 +186,10 @@ bool RadioLibWrapper::isChannelActive() {
   if (_threshold == 0) return false;    // interference check is disabled
 
   int16_t result = performChannelScan();
-  // scanChannel() leaves radio in standby — restart RX regardless of result
+  // scanChannel() triggers DIO interrupt (CAD done) which sets STATE_INT_READY
+  // via setFlag() ISR. Clear it before restarting RX so recvRaw() doesn't
+  // try to read a non-existent packet and count a spurious recv error.
+  state = STATE_IDLE;
   startRecv();
   return result != RADIOLIB_CHANNEL_FREE;
 }

From 7c8e09245760c71a64f14ca46b4ff6b8dcdd3aa9 Mon Sep 17 00:00:00 2001
From: Wessel Nieboer <wessel@weebl.me>
Date: Wed, 3 Jun 2026 10:13:10 +0200
Subject: [PATCH 23/23] Have CAD be a separate toggle (set cad on/off)

---
 docs/cli_commands.md                      | 14 ++++++++++++++
 examples/companion_radio/MyMesh.cpp       |  5 ++++-
 examples/companion_radio/MyMesh.h         |  1 +
 examples/simple_repeater/MyMesh.cpp       |  3 ++-
 examples/simple_repeater/MyMesh.h         |  3 +++
 examples/simple_room_server/MyMesh.cpp    |  3 ++-
 examples/simple_room_server/MyMesh.h      |  3 +++
 examples/simple_sensor/SensorMesh.cpp     |  6 +++++-
 examples/simple_sensor/SensorMesh.h       |  1 +
 src/Dispatcher.cpp                        |  1 +
 src/Dispatcher.h                          |  3 +++
 src/helpers/CommonCLI.cpp                 | 13 +++++++++++--
 src/helpers/CommonCLI.h                   |  1 +
 src/helpers/radiolib/RadioLibWrappers.cpp | 23 +++++++++++++++--------
 src/helpers/radiolib/RadioLibWrappers.h   |  2 ++
 15 files changed, 68 insertions(+), 14 deletions(-)

diff --git a/docs/cli_commands.md b/docs/cli_commands.md
index ce0e7da1..c06f5e12 100644
--- a/docs/cli_commands.md
+++ b/docs/cli_commands.md
@@ -578,6 +578,20 @@ This document provides an overview of CLI commands that can be sent to MeshCore
 
 ---
 
+#### Enable or disable hardware Channel Activity Detection (CAD)
+**Usage:**
+- `get cad`
+- `set cad <on|off>`
+
+**Description:** When enabled, the radio performs a hardware Channel Activity Detection scan before transmitting and defers if the channel is busy. Runs independently of `int.thresh` — either, both, or none may be active.
+
+**Parameters:**
+- `on|off`: Enable or disable hardware CAD
+
+**Default:** `off`
+
+---
+
 #### View or change the AGC Reset Interval
 **Usage:**
 - `get agc.reset.interval`
diff --git a/examples/companion_radio/MyMesh.cpp b/examples/companion_radio/MyMesh.cpp
index 2433f595..5fb9bf9d 100644
--- a/examples/companion_radio/MyMesh.cpp
+++ b/examples/companion_radio/MyMesh.cpp
@@ -259,7 +259,10 @@ float MyMesh::getAirtimeBudgetFactor() const {
 }
 
 int MyMesh::getInterferenceThreshold() const {
-  return 1; // non-zero enables hardware CAD (Channel Activity Detection) before TX
+  return 0; // disabled for now, until currentRSSI() problem is resolved
+}
+bool MyMesh::getCADEnabled() const {
+  return true; // hardware CAD before TX (no CLI toggle on companion; enabled by default)
 }
 
 int MyMesh::calcRxDelay(float score, uint32_t air_time) const {
diff --git a/examples/companion_radio/MyMesh.h b/examples/companion_radio/MyMesh.h
index 43d3950b..f4190f30 100644
--- a/examples/companion_radio/MyMesh.h
+++ b/examples/companion_radio/MyMesh.h
@@ -105,6 +105,7 @@ public:
 protected:
   float getAirtimeBudgetFactor() const override;
   int getInterferenceThreshold() const override;
+  bool getCADEnabled() const override;
   int calcRxDelay(float score, uint32_t air_time) const override;
   uint32_t getRetransmitDelay(const mesh::Packet *packet) override;
   uint32_t getDirectRetransmitDelay(const mesh::Packet *packet) override;
diff --git a/examples/simple_repeater/MyMesh.cpp b/examples/simple_repeater/MyMesh.cpp
index dd282ec8..5cc3a9a1 100644
--- a/examples/simple_repeater/MyMesh.cpp
+++ b/examples/simple_repeater/MyMesh.cpp
@@ -892,7 +892,8 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.flood_max = 64;
   _prefs.flood_max_unscoped = 64;
   _prefs.flood_max_advert = 8;
-  _prefs.interference_threshold = 1; // non-zero enables hardware CAD before TX
+  _prefs.interference_threshold = 0; // disabled
+  _prefs.cad_enabled = 0;            // hardware CAD before TX (off by default; 'set cad on')
 
   // bridge defaults
   _prefs.bridge_enabled = 1;    // enabled
diff --git a/examples/simple_repeater/MyMesh.h b/examples/simple_repeater/MyMesh.h
index 7597c6c6..24c4b1f2 100644
--- a/examples/simple_repeater/MyMesh.h
+++ b/examples/simple_repeater/MyMesh.h
@@ -150,6 +150,9 @@ protected:
   int getInterferenceThreshold() const override {
     return _prefs.interference_threshold;
   }
+  bool getCADEnabled() const override {
+    return _prefs.cad_enabled;
+  }
   int getAGCResetInterval() const override {
     return ((int)_prefs.agc_reset_interval) * 4000;   // milliseconds
   }
diff --git a/examples/simple_room_server/MyMesh.cpp b/examples/simple_room_server/MyMesh.cpp
index 97ec80ac..12d0b0c3 100644
--- a/examples/simple_room_server/MyMesh.cpp
+++ b/examples/simple_room_server/MyMesh.cpp
@@ -649,7 +649,8 @@ MyMesh::MyMesh(mesh::MainBoard &board, mesh::Radio &radio, mesh::MillisecondCloc
   _prefs.flood_max = 64;
   _prefs.flood_max_unscoped = 64;
   _prefs.flood_max_advert = 8;
-  _prefs.interference_threshold = 1; // non-zero enables hardware CAD before TX
+  _prefs.interference_threshold = 0; // disabled
+  _prefs.cad_enabled = 0;            // hardware CAD before TX (off by default; 'set cad on')
 #ifdef ROOM_PASSWORD
   StrHelper::strncpy(_prefs.guest_password, ROOM_PASSWORD, sizeof(_prefs.guest_password));
 #endif
diff --git a/examples/simple_room_server/MyMesh.h b/examples/simple_room_server/MyMesh.h
index 5277ddad..e9e53ec9 100644
--- a/examples/simple_room_server/MyMesh.h
+++ b/examples/simple_room_server/MyMesh.h
@@ -144,6 +144,9 @@ protected:
   int getInterferenceThreshold() const override {
     return _prefs.interference_threshold;
   }
+  bool getCADEnabled() const override {
+    return _prefs.cad_enabled;
+  }
   int getAGCResetInterval() const override {
     return ((int)_prefs.agc_reset_interval) * 4000;   // milliseconds
   }
diff --git a/examples/simple_sensor/SensorMesh.cpp b/examples/simple_sensor/SensorMesh.cpp
index 2a2c7feb..59c9aa09 100644
--- a/examples/simple_sensor/SensorMesh.cpp
+++ b/examples/simple_sensor/SensorMesh.cpp
@@ -323,6 +323,9 @@ uint32_t SensorMesh::getDirectRetransmitDelay(const mesh::Packet* packet) {
 int SensorMesh::getInterferenceThreshold() const {
   return _prefs.interference_threshold;
 }
+bool SensorMesh::getCADEnabled() const {
+  return _prefs.cad_enabled;
+}
 int SensorMesh::getAGCResetInterval() const {
   return ((int)_prefs.agc_reset_interval) * 4000;   // milliseconds
 }
@@ -725,7 +728,8 @@ SensorMesh::SensorMesh(mesh::MainBoard& board, mesh::Radio& radio, mesh::Millise
   _prefs.flood_advert_interval = 0;   // disabled
   _prefs.disable_fwd = true;
   _prefs.flood_max = 64;
-  _prefs.interference_threshold = 1;  // non-zero enables hardware CAD before TX
+  _prefs.interference_threshold = 0;  // disabled
+  _prefs.cad_enabled = 0;             // hardware CAD before TX (off by default; 'set cad on')
 
   // GPS defaults
   _prefs.gps_enabled = 0;
diff --git a/examples/simple_sensor/SensorMesh.h b/examples/simple_sensor/SensorMesh.h
index c9f135f6..1d65b877 100644
--- a/examples/simple_sensor/SensorMesh.h
+++ b/examples/simple_sensor/SensorMesh.h
@@ -120,6 +120,7 @@ protected:
   uint32_t getRetransmitDelay(const mesh::Packet* packet) override;
   uint32_t getDirectRetransmitDelay(const mesh::Packet* packet) override;
   int getInterferenceThreshold() const override;
+  bool getCADEnabled() const override;
   int getAGCResetInterval() const override;
   void onAnonDataRecv(mesh::Packet* packet, const uint8_t* secret, const mesh::Identity& sender, uint8_t* data, size_t len) override;
   int searchPeersByHash(const uint8_t* hash) override;
diff --git a/src/Dispatcher.cpp b/src/Dispatcher.cpp
index 9d7a1113..c0610b7f 100644
--- a/src/Dispatcher.cpp
+++ b/src/Dispatcher.cpp
@@ -66,6 +66,7 @@ uint32_t Dispatcher::getCADFailMaxDuration() const {
 void Dispatcher::loop() {
   if (millisHasNowPassed(next_floor_calib_time)) {
     _radio->triggerNoiseFloorCalibrate(getInterferenceThreshold());
+    _radio->setCADEnabled(getCADEnabled());
     next_floor_calib_time = futureMillis(NOISE_FLOOR_CALIB_INTERVAL);
   }
   _radio->loop();
diff --git a/src/Dispatcher.h b/src/Dispatcher.h
index dd032f13..aad6cba3 100644
--- a/src/Dispatcher.h
+++ b/src/Dispatcher.h
@@ -65,6 +65,8 @@ public:
 
   virtual void triggerNoiseFloorCalibrate(int threshold) { }
 
+  virtual void setCADEnabled(bool enable) { }
+
   virtual void resetAGC() { }
 
   virtual bool isInRecvMode() const = 0;
@@ -166,6 +168,7 @@ protected:
   virtual uint32_t getCADFailRetryDelay() const;
   virtual uint32_t getCADFailMaxDuration() const;
   virtual int getInterferenceThreshold() const { return 0; }    // disabled by default
+  virtual bool getCADEnabled() const { return false; }    // hardware CAD disabled by default
   virtual int getAGCResetInterval() const { return 0; }    // disabled by default
   virtual unsigned long getDutyCycleWindowMs() const { return 3600000; }
 
diff --git a/src/helpers/CommonCLI.cpp b/src/helpers/CommonCLI.cpp
index 5a5d1eab..82e53743 100644
--- a/src/helpers/CommonCLI.cpp
+++ b/src/helpers/CommonCLI.cpp
@@ -92,7 +92,8 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     file.read((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));         // 291
     file.read((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));             // 292
     file.read((uint8_t *)&_prefs->radio_fem_rxgain, sizeof(_prefs->radio_fem_rxgain));             // 293
-    // next: 294
+    file.read((uint8_t *)&_prefs->cad_enabled, sizeof(_prefs->cad_enabled));                       // 294
+    // next: 295
 
     // sanitise bad pref values
     _prefs->rx_delay_base = constrain(_prefs->rx_delay_base, 0, 20.0f);
@@ -123,6 +124,7 @@ void CommonCLI::loadPrefsInt(FILESYSTEM* fs, const char* filename) {
     // sanitise settings
     _prefs->rx_boosted_gain = constrain(_prefs->rx_boosted_gain, 0, 1); // boolean
     _prefs->radio_fem_rxgain = constrain(_prefs->radio_fem_rxgain, 0, 1); // boolean
+    _prefs->cad_enabled = constrain(_prefs->cad_enabled, 0, 1); // boolean
 
     file.close();
   }
@@ -187,7 +189,8 @@ void CommonCLI::savePrefs(FILESYSTEM* fs) {
     file.write((uint8_t *)&_prefs->flood_max_unscoped, sizeof(_prefs->flood_max_unscoped));         // 291
     file.write((uint8_t *)&_prefs->flood_max_advert, sizeof(_prefs->flood_max_advert));             // 292
     file.write((uint8_t *)&_prefs->radio_fem_rxgain, sizeof(_prefs->radio_fem_rxgain));             // 293
-    // next: 294
+    file.write((uint8_t *)&_prefs->cad_enabled, sizeof(_prefs->cad_enabled));                       // 294
+    // next: 295
 
     file.close();
   }
@@ -503,6 +506,10 @@ void CommonCLI::handleSetCmd(uint32_t sender_timestamp, char* command, char* rep
     _prefs->interference_threshold = atoi(&config[11]);
     savePrefs();
     strcpy(reply, "OK");
+  } else if (memcmp(config, "cad ", 4) == 0) {
+    _prefs->cad_enabled = memcmp(&config[4], "on", 2) == 0;
+    savePrefs();
+    strcpy(reply, "OK");
   } else if (memcmp(config, "agc.reset.interval ", 19) == 0) {
     _prefs->agc_reset_interval = atoi(&config[19]) / 4;
     savePrefs();
@@ -801,6 +808,8 @@ void CommonCLI::handleGetCmd(uint32_t sender_timestamp, char* command, char* rep
     sprintf(reply, "> %s", StrHelper::ftoa(_prefs->airtime_factor));
   } else if (memcmp(config, "int.thresh", 10) == 0) {
     sprintf(reply, "> %d", (uint32_t) _prefs->interference_threshold);
+  } else if (memcmp(config, "cad", 3) == 0) {
+    sprintf(reply, "> %s", _prefs->cad_enabled ? "on" : "off");
   } else if (memcmp(config, "agc.reset.interval", 18) == 0) {
     sprintf(reply, "> %d", ((uint32_t) _prefs->agc_reset_interval) * 4);
   } else if (memcmp(config, "multi.acks", 10) == 0) {
diff --git a/src/helpers/CommonCLI.h b/src/helpers/CommonCLI.h
index ffeadc5b..10cb00c7 100644
--- a/src/helpers/CommonCLI.h
+++ b/src/helpers/CommonCLI.h
@@ -64,6 +64,7 @@ struct NodePrefs { // persisted to file
   uint8_t radio_fem_rxgain; // LoRa FEM RX gain setting
   uint8_t path_hash_mode;   // which path mode to use when sending
   uint8_t loop_detect;
+  uint8_t cad_enabled;      // hardware Channel Activity Detection before TX (boolean)
 };
 
 class CommonCLICallbacks {
diff --git a/src/helpers/radiolib/RadioLibWrappers.cpp b/src/helpers/radiolib/RadioLibWrappers.cpp
index 5d68d7e9..5e72336c 100644
--- a/src/helpers/radiolib/RadioLibWrappers.cpp
+++ b/src/helpers/radiolib/RadioLibWrappers.cpp
@@ -36,6 +36,7 @@ void RadioLibWrapper::begin() {
 
   _noise_floor = 0;
   _threshold = 0;
+  _cad_enabled = false;
 
   // start average out some samples
   _num_floor_samples = 0;
@@ -183,15 +184,21 @@ int16_t RadioLibWrapper::performChannelScan() {
 }
 
 bool RadioLibWrapper::isChannelActive() {
-  if (_threshold == 0) return false;    // interference check is disabled
+  // int.thresh: RSSI-based interference detection (relative to noise floor)
+  if (_threshold != 0 && getCurrentRSSI() > _noise_floor + _threshold) return true;
 
-  int16_t result = performChannelScan();
-  // scanChannel() triggers DIO interrupt (CAD done) which sets STATE_INT_READY
-  // via setFlag() ISR. Clear it before restarting RX so recvRaw() doesn't
-  // try to read a non-existent packet and count a spurious recv error.
-  state = STATE_IDLE;
-  startRecv();
-  return result != RADIOLIB_CHANNEL_FREE;
+  // cad: hardware channel activity detection
+  if (_cad_enabled) {
+    int16_t result = performChannelScan();
+    // scanChannel() triggers DIO interrupt (CAD done) which sets STATE_INT_READY
+    // via setFlag() ISR. Clear it before restarting RX so recvRaw() doesn't
+    // try to read a non-existent packet and count a spurious recv error.
+    state = STATE_IDLE;
+    startRecv();
+    if (result != RADIOLIB_CHANNEL_FREE) return true;
+  }
+
+  return false;
 }
 
 float RadioLibWrapper::getLastRSSI() const {
diff --git a/src/helpers/radiolib/RadioLibWrappers.h b/src/helpers/radiolib/RadioLibWrappers.h
index c1ece644..9943bcab 100644
--- a/src/helpers/radiolib/RadioLibWrappers.h
+++ b/src/helpers/radiolib/RadioLibWrappers.h
@@ -9,6 +9,7 @@ protected:
   mesh::MainBoard* _board;
   uint32_t n_recv, n_sent, n_recv_errors;
   int16_t _noise_floor, _threshold;
+  bool _cad_enabled;
   uint16_t _num_floor_samples;
   int32_t _floor_sample_sum;
   uint8_t _preamble_sf;
@@ -50,6 +51,7 @@ public:
 
   int getNoiseFloor() const override { return _noise_floor; }
   void triggerNoiseFloorCalibrate(int threshold) override;
+  void setCADEnabled(bool enable) override { _cad_enabled = enable; }
   void resetAGC() override;
 
   void loop() override;