Few adjustments after testing.

src/helpers/nrf52/SerialBLEInterface.cpp

@@ -25,28 +25,14 @@ void SerialBLEInterface::begin(const char* device_name, uint32_t pin_code) {
   char charpin[20];
   sprintf(charpin, "%d", pin_code);
 
-  Bluefruit.configPrphBandwidth(
+  Bluefruit.configPrphBandwidth(BANDWIDTH_MAX);
+  Bluefruit.configPrphConn(250, BLE_GAP_EVENT_LENGTH_MIN, 16, 16);  // increase MTU
 #ifdef BLE_LOW_POWER
-    BANDWIDTH_NORMAL
+  Bluefruit.setTxPower(0);
 #else
-    BANDWIDTH_MAX
+  Bluefruit.setTxPower(4);
 #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(
-#ifdef BLE_LOW_POWER
-    0
-#else
-    4
-#endif
-  );    // Check bluefruit.h for supported values
   Bluefruit.setName(device_name);
 
   Bluefruit.Security.setMITM(true);
@@ -98,13 +84,7 @@ 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(
+  Bluefruit.Advertising.setInterval(32, 1600);
-#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