Implement BLE OTA

source/ble_config.cpp

@@ -133,6 +133,9 @@ void onCommandWrite(uint16_t h, BLECharacteristic* c, uint8_t* d, uint16_t l) {
   if (l < 1) return;
   if (d[0] == 0x01) pendingCal   = true;
   if (d[0] == 0xFF) pendingReset = true;
+  #ifdef FEATURE_OTA
+    if (d[0] == 0x02) pendingOTA = true;
+  #endif
 }
 
 #ifdef FEATURE_IMU_STREAM
@@ -153,7 +156,7 @@ void setupConfigService() {
   cfgBlob.begin();
   pushConfigBlob();
 
-  cfgCommand.setProperties(CHR_PROPS_WRITE);
+  cfgCommand.setProperties(CHR_PROPS_WRITE | CHR_PROPS_WRITE_WO_RESP);
   cfgCommand.setPermission(SECMODE_OPEN, SECMODE_OPEN);
   cfgCommand.setFixedLen(1);
   cfgCommand.setWriteCallback(onCommandWrite);

source/config.h

@@ -11,6 +11,7 @@
 #define FEATURE_BATTERY_MONITOR
 #define FEATURE_BOOT_LOOP_DETECT
 #define FEATURE_PHYSICAL_BUTTONS
+#define FEATURE_OTA
 
 // Debug 
 // #define DEBUG
@@ -205,6 +206,9 @@ extern float cachedTempC;
 
 extern bool pendingCal;
 extern bool pendingReset;
+#ifdef FEATURE_OTA
+  extern bool pendingOTA;
+#endif
 extern ChargeStatus lastChargeStatus;
 extern int           idleFrames;
 extern unsigned long idleStartMs;

source/main.cpp

@@ -117,6 +117,9 @@ float cachedTempC = 25.0f;
 uint32_t loopStalls = 0;          // loop iterations where dt > 20ms (behind schedule)
 bool pendingCal   = false;
 bool pendingReset = false;
+#ifdef FEATURE_OTA
+  bool pendingOTA = false;
+#endif
 
 // Jerk-based shock detection - freeze cursor during tap impacts, doesn't work well yet!
 unsigned long shockFreezeUntil = 0;
@@ -299,10 +302,28 @@ void loop() {
     char cmd = Serial.read();
     if (cmd == 'c') { Serial.println("[SERIAL] Calibrate"); pendingCal   = true; }
     if (cmd == 'r') { Serial.println("[SERIAL] Reset");     pendingReset = true; }
+    #ifdef FEATURE_OTA
+      if (cmd == 'o') { Serial.println("[SERIAL] OTA DFU"); pendingOTA = true; }
+    #endif
   }
 
   if (pendingCal)   { pendingCal = false; calibrateGyroBias(); prevAx = imu.readFloatAccelX(); prevAy = imu.readFloatAccelY(); prevAz = imu.readFloatAccelZ(); }
   if (pendingReset) { pendingReset = false; factoryReset(); }
+  #ifdef FEATURE_OTA
+    if (pendingOTA) {
+      pendingOTA = false;
+      Serial.println("[OTA] Disconnecting BLE and entering bootloader DFU mode...");
+      Serial.flush();
+      // Gracefully close the BLE connection first so the host can detect the
+      // disconnect and be ready to see DfuTarg advertise after the reboot.
+      if (Bluefruit.connected()) {
+        Bluefruit.disconnect(0);
+        delay(300);
+      }
+      delay(200);
+      enterOTADfu();  // Adafruit nRF52 core: sets GPREGRET correctly and resets into bootloader OTA mode
+    }
+  #endif
 
   // Heartbeat LED
   if (now - lastHeartbeat >= HEARTBEAT_MS) {