Updated BLE functionality for low power mode in SerialBLEInterface. Updated platformio.ini to enable low power mode and added DC/DC converter support in T1000eBoard for improved power efficiency.

src/helpers/nrf52/SerialBLEInterface.cpp

@@ -25,10 +25,28 @@ void SerialBLEInterface::begin(const char* device_name, uint32_t pin_code) {
   char charpin[20];
   sprintf(charpin, "%d", pin_code);
 
-  Bluefruit.configPrphBandwidth(BANDWIDTH_MAX);
+  Bluefruit.configPrphBandwidth(
-  Bluefruit.configPrphConn(250, BLE_GAP_EVENT_LENGTH_MIN, 16, 16);  // increase MTU
+#ifdef BLE_LOW_POWER
+    BANDWIDTH_NORMAL
+#else
+    BANDWIDTH_MAX
+#endif
+  );
+  Bluefruit.configPrphConn(
+#ifdef BLE_LOW_POWER
+    400, BLE_GAP_EVENT_LENGTH_MIN, 8, 8
+#else
+    250, BLE_GAP_EVENT_LENGTH_MIN, 16, 16  // increase MTU
+#endif
+  );
   Bluefruit.begin();
-  Bluefruit.setTxPower(4);    // Check bluefruit.h for supported values
+  Bluefruit.setTxPower(
+#ifdef BLE_LOW_POWER
+    0
+#else
+    4
+#endif
+  );    // Check bluefruit.h for supported values
   Bluefruit.setName(device_name);
 
   Bluefruit.Security.setMITM(true);
@@ -80,7 +98,13 @@ 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, 244);    // in unit of 0.625 ms
+  Bluefruit.Advertising.setInterval(
+#ifdef BLE_LOW_POWER
+    160, 1600
+#else
+    32, 244
+#endif
+  );    // in unit of 0.625 ms
   Bluefruit.Advertising.setFastTimeout(30);      // number of seconds in fast mode
   Bluefruit.Advertising.start(0);                // 0 = Don't stop advertising after n seconds
 

variants/t1000-e/T1000eBoard.cpp

@@ -11,6 +11,9 @@ void T1000eBoard::begin() {
 
   sd_power_mode_set(NRF_POWER_MODE_LOWPWR);
 
+  // Enable DC/DC converter for improved power efficiency
+  NRF_POWER->DCDCEN = 1;
+
 #ifdef BUTTON_PIN
   pinMode(BATTERY_PIN, INPUT);
   pinMode(BUTTON_PIN, INPUT);

variants/t1000-e/platformio.ini

@@ -100,6 +100,7 @@ build_flags = ${t1000-e.build_flags}
   -D MAX_CONTACTS=100
   -D MAX_GROUP_CHANNELS=8
   -D BLE_PIN_CODE=123456
+  -D BLE_LOW_POWER=1
 ;  -D BLE_DEBUG_LOGGING=1
 ;  -D MESH_PACKET_LOGGING=1
 ;  -D MESH_DEBUG=1