Refresh nRF52 Companion BLE name without reboot

examples/companion_radio/MyMesh.cpp

@@ -6663,11 +6663,19 @@ bool MyMesh::applyAndSaveBluetoothName(const char* value, char* reply,
 
   if (use_default) {
     snprintf(reply, reply_size,
+#if defined(NRF52_PLATFORM)
+             "OK - Bluetooth name follows %s<node name>; advertising refreshes after disconnect",
+#else
              "OK - Bluetooth name follows %s<node name>; reboot required",
+#endif
              BLE_NAME_PREFIX);
   } else {
     snprintf(reply, reply_size,
+#if defined(NRF52_PLATFORM)
+             "OK - Bluetooth name saved as '%s'; advertising refreshes after disconnect", value);
+#else
              "OK - Bluetooth name saved as '%s'; reboot required", value);
+#endif
   }
   return true;
 }

examples/companion_radio/main.cpp

@@ -2323,6 +2323,24 @@ void halt() {
     startCompanionBluetooth();
   }
 
+#if defined(NRF52_PLATFORM)
+  static void serviceCompanionBluetoothName() {
+    if (!companion_bluetooth_initialized) return;
+    static uint32_t last_check = 0;
+    const uint32_t now = millis();
+    if ((uint32_t)(now - last_check) < 250) return;
+    last_check = now;
+
+    const CompanionNodePrefs* prefs = the_mesh.getNodePrefs();
+    if (prefs == nullptr) return;
+    const bool custom =
+        mesh::companion::hasCustomBluetoothName(prefs->bluetooth_name);
+    bluetooth_interface.refreshName(custom ? "" : BLE_NAME_PREFIX,
+                                    custom ? prefs->bluetooth_name
+                                           : prefs->node_name);
+  }
+#endif
+
   static void serviceCompanionBluetoothIdentity() {
     if (!companion_bluetooth_initialized) return;
 
@@ -3472,5 +3490,8 @@ void loop() {
 #endif
   serviceCompanionBluetoothIdentity();
   serviceCompanionBluetoothControl();
+#if defined(NRF52_PLATFORM)
+  serviceCompanionBluetoothName();
+#endif
 #endif
 }

src/helpers/nrf52/SerialBLEInterface.cpp

@@ -30,6 +30,27 @@
 
 static SerialBLEInterface* instance = nullptr;
 
+static bool formatDeviceName(char* dest, size_t capacity,
+                             const char* prefix, const char* name) {
+  if (dest == nullptr || capacity == 0 || prefix == nullptr || name == nullptr) {
+    return false;
+  }
+  char resolved_name[32];
+  const char* suffix = name;
+  if (strcmp(name, "@@MAC") == 0) {
+    ble_gap_addr_t addr;
+    if (sd_ble_gap_addr_get(&addr) == NRF_SUCCESS) {
+      snprintf(resolved_name, sizeof(resolved_name),
+               "%02X%02X%02X%02X%02X%02X",
+               addr.addr[5], addr.addr[4], addr.addr[3], addr.addr[2],
+               addr.addr[1], addr.addr[0]);
+      suffix = resolved_name;
+    }
+  }
+  const int length = snprintf(dest, capacity, "%s%s", prefix, suffix);
+  return length >= 0 && length < (int)capacity;
+}
+
 #if defined(COMPANION_RADIO_FULL) && COMPANION_RADIO_FULL
 // Bluefruit's bonded CCCD flash write resets some nRF52 Full Companions.
 // Retain the small SoftDevice system-attribute image in RAM for reconnects
@@ -616,22 +637,8 @@ bool SerialBLEInterface::begin(const char* prefix, const char* name,
     }
   }
  
-  char resolved_name[32];
-  const char* suffix = name;
-  if (strcmp(name, "@@MAC") == 0) {
-    ble_gap_addr_t addr;
-    if (sd_ble_gap_addr_get(&addr) == NRF_SUCCESS) {
-      snprintf(resolved_name, sizeof(resolved_name),
-               "%02X%02X%02X%02X%02X%02X",
-               addr.addr[5], addr.addr[4], addr.addr[3], addr.addr[2],
-               addr.addr[1], addr.addr[0]);
-      suffix = resolved_name;
-    }
-  }
-  char dev_name[32+16];
-  const int dev_name_len = snprintf(dev_name, sizeof(dev_name), "%s%s",
-                                    prefix, suffix);
-  if (dev_name_len < 0 || dev_name_len >= (int)sizeof(dev_name)) {
+  char dev_name[sizeof(_active_name)];
+  if (!formatDeviceName(dev_name, sizeof(dev_name), prefix, name)) {
     strncpy(_begin_failure, "Bluetooth device name is too long",
             sizeof(_begin_failure) - 1);
     _begin_failure[sizeof(_begin_failure) - 1] = 0;
@@ -660,6 +667,7 @@ bool SerialBLEInterface::begin(const char* prefix, const char* name,
   
   Bluefruit.setTxPower(BLE_TX_POWER);
   Bluefruit.setName(dev_name);
+  memcpy(_active_name, dev_name, strlen(dev_name) + 1);
 
   Bluefruit.Security.setMITM(true);
   Bluefruit.Security.setPIN(charpin);
@@ -752,6 +760,35 @@ bool SerialBLEInterface::begin(const char* prefix, const char* name,
   return true;
 }
 
+bool SerialBLEInterface::refreshName(const char* prefix, const char* name) {
+  if (!_begin_ready || _conn_handle != BLE_CONN_HANDLE_INVALID) return false;
+
+  char desired[sizeof(_active_name)];
+  if (!formatDeviceName(desired, sizeof(desired), prefix, name)) return false;
+  if (strcmp(desired, _active_name) == 0) return true;
+
+  const bool was_advertising = isAdvertising();
+  if (was_advertising && !Bluefruit.Advertising.stop()) return false;
+
+  Bluefruit.setName(desired);
+  char actual[sizeof(_active_name)];
+  const size_t actual_len = Bluefruit.getName(actual, sizeof(actual));
+  if (actual_len != strlen(desired)
+      || memcmp(actual, desired, actual_len) != 0) {
+    if (was_advertising) startAdvertising("advertising failed after name refresh");
+    return false;
+  }
+
+  // Directed bonded-only advertisements have no payload to refresh.
+  if (!_bonded_only) {
+    Bluefruit.ScanResponse.clearData();
+    Bluefruit.ScanResponse.addName();
+  }
+  memcpy(_active_name, desired, strlen(desired) + 1);
+  if (was_advertising) startAdvertising("advertising failed after name refresh");
+  return true;
+}
+
 bool SerialBLEInterface::takeSuccessfulConnection(
     mesh::companion::BluetoothPeerIdentity* peer) {
   if (!_successfulConnectionPending.load(std::memory_order_acquire)) {

src/helpers/nrf52/SerialBLEInterface.h

@@ -65,6 +65,7 @@ class SerialBLEInterface : public BaseSerialInterface {
   bool _begin_attempted = false;
   bool _begin_ready = false;
   char _begin_failure[96] = {};
+  char _active_name[48] = {};
   bool _isDeviceConnected;
   uint16_t _conn_handle;
   unsigned long _last_health_check;
@@ -166,6 +167,9 @@ public:
              bool clear_bonds = false, bool stealth_pair_once = false,
              const mesh::companion::BluetoothPeerIdentity*
                  bonded_only_peer = nullptr);
+  // Refresh the GAP and scan-response name after a saved node/Bluetooth name
+  // changes. A connected phone is left alone; the next idle pass applies it.
+  bool refreshName(const char* prefix, const char* name);
   // Kept after a failed begin so a normal Companion terminal can report the
   // cause even when early USB logging was not available.
   const char* beginFailure() const { return _begin_failure; }