Allow WiFi credentials to be set at runtime

Store ssid/pwd in NodePrefs and set them with 'set wifi.ssid' /
'set wifi.pwd' over USB serial; build-time WIFI_SSID/WIFI_PWD stay as
the fallback. Headless WiFi builds get the config CLI on Serial, which
is otherwise unused there.

examples/companion_radio/MyMesh.cpp

@@ -932,6 +932,7 @@ MyMesh::MyMesh(mesh::Radio &radio, mesh::RNG &rng, mesh::RTCClock &rtc, SimpleMe
       _serial(NULL), telemetry(MAX_PACKET_PAYLOAD - 4), _store(&store), _ui(ui), _iter(0) {
   _iter_started = false;
   _cli_rescue = false;
+  cli_command[0] = 0;
   offline_queue_len = 0;
   app_target_ver = 0;
   clearPendingReqs();
@@ -2156,6 +2157,35 @@ bool MyMesh::handleCommand(const char* command, uint32_t sender_timestamp, char*
     return true;
   }
 
+#ifdef WIFI_SSID
+  // local console only: these are credentials, and remote admin has no business with them
+  if (sender_timestamp == 0) {
+    if (memcmp(command, "set wifi.ssid ", 14) == 0) {
+      StrHelper::strncpy(_prefs.wifi_ssid, &command[14], sizeof(_prefs.wifi_ssid));
+      savePrefs();
+      sprintf(reply, "> wifi.ssid is now %s (set wifi.pwd too, then reboot)", _prefs.wifi_ssid);
+      return true;
+    }
+    if (memcmp(command, "set wifi.pwd ", 13) == 0) {
+      StrHelper::strncpy(_prefs.wifi_pwd, &command[13], sizeof(_prefs.wifi_pwd));
+      savePrefs();
+      strcpy(reply, "> wifi.pwd updated (reboot to apply)");
+      return true;
+    }
+    if (strcmp(command, "set wifi.clear") == 0) {
+      _prefs.wifi_ssid[0] = 0;
+      _prefs.wifi_pwd[0] = 0;
+      savePrefs();
+      strcpy(reply, "> wifi config cleared, using build-time credentials (reboot to apply)");
+      return true;
+    }
+    if (strcmp(command, "get wifi.ssid") == 0) {   // no 'get wifi.pwd', by design
+      sprintf(reply, "> %s", _prefs.wifi_ssid[0] ? _prefs.wifi_ssid : "(build-time)");
+      return true;
+    }
+  }
+#endif
+
   if (strcmp(command, "board") == 0) {
     strcpy(reply, board.getManufacturerName());
     return true;
@@ -2386,6 +2416,10 @@ void MyMesh::loop() {
     checkCLIRescueCmd();
   } else {
     checkSerialInterface();
+#if defined(WIFI_SSID) && !defined(ENABLE_USB_INTERFACE)
+    // headless WiFi build: USB serial isn't a companion transport, so use it for config
+    checkCLIRescueCmd();
+#endif
   }
 
   // is there are pending dirty contacts write needed?

examples/companion_radio/NodePrefs.h

@@ -44,6 +44,10 @@ public:
   char default_scope_name[31];
   uint8_t default_scope_key[16];
   int8_t tz_offset = 0;
+#ifdef WIFI_SSID
+  char wifi_ssid[33] = {0};   // if empty, the compile-time WIFI_SSID is used
+  char wifi_pwd[64] = {0};
+#endif
 
 private:
   class RadioPrefs : public CommonRadioPrefs {
@@ -160,6 +164,20 @@ private:
 
   DynamicConfigSerializer custom;
 
+#ifdef WIFI_SSID
+  class WiFiPrefs : public ConfigSerializer {
+    NodePrefs* _parent;
+  protected:
+    void structure() override {
+      def("ssid", _parent->wifi_ssid, sizeof(_parent->wifi_ssid));
+      def("pwd", _parent->wifi_pwd, sizeof(_parent->wifi_pwd));
+    }
+  public:
+    WiFiPrefs(NodePrefs* parent) : _parent(parent) { }
+  };
+  WiFiPrefs wifi;
+#endif
+
 protected:
   void structure() override {
     def("name", node_name, sizeof(node_name));
@@ -172,9 +190,16 @@ protected:
     def("repeat", repeat);
     def("comp", companion);
     def("custom", custom);
+#ifdef WIFI_SSID
+    def("wifi", wifi);
+#endif
   }
 public:
-  NodePrefs() : radio(this), gps(this), companion(this), custom(&radio) {
+  NodePrefs() : radio(this), gps(this), companion(this), custom(&radio)
+#ifdef WIFI_SSID
+    , wifi(this)
+#endif
+  {
     node_name[0] = 0;
     default_scope_name[0] = 0;
     memset(default_scope_key, 0, sizeof(default_scope_key));

examples/companion_radio/main.cpp

@@ -110,6 +110,8 @@ void halt() {
 #ifdef WIFI_SSID
   bool wifi_needs_reconnect = false;
   unsigned long last_wifi_reconnect_attempt = 0;
+  const char* wifi_ssid = WIFI_SSID;   // replaced by stored prefs, if set
+  const char* wifi_pwd = WIFI_PWD;
 #endif
 
 void setup() {
@@ -206,7 +208,14 @@ void setup() {
   });
 #endif
 
-  WiFi.begin(WIFI_SSID, WIFI_PWD);
+  // stored credentials win over the build-time ones ('set wifi.ssid <x>' over USB serial)
+  if (the_mesh.getNodePrefs()->wifi_ssid[0]) {
+    wifi_ssid = the_mesh.getNodePrefs()->wifi_ssid;
+    wifi_pwd = the_mesh.getNodePrefs()->wifi_pwd;
+  }
+  WIFI_DEBUG_PRINTLN("connecting to %s", wifi_ssid);
+
+  WiFi.begin(wifi_ssid, wifi_pwd);
   wifi_interface.begin(TCP_PORT);
   interface_manager.addInterface(InterfaceType::WiFi, &wifi_interface);
 #endif
@@ -273,7 +282,7 @@ void loop() {
   if (wifi_needs_reconnect && (millis() - last_wifi_reconnect_attempt > 10000)) {
     WIFI_DEBUG_PRINTLN("Attempting manual WiFi reconnect...");
     #if defined(RP2040_PLATFORM)
-      WiFi.begin(WIFI_SSID, WIFI_PWD);   // no reconnect() on this platform
+      WiFi.begin(wifi_ssid, wifi_pwd);   // no reconnect() on this platform
     #else
       WiFi.disconnect();
       WiFi.reconnect();