don't mark as connected until connection secured

src/helpers/nrf52/SerialBLEInterface.cpp

@@ -4,10 +4,7 @@ static SerialBLEInterface* instance;
 
 void SerialBLEInterface::onConnect(uint16_t connection_handle) {
   BLE_DEBUG_PRINTLN("SerialBLEInterface: connected");
-  if(instance){
-    instance->_isDeviceConnected = true;
-    // no need to stop advertising on connect, as the ble stack does this automatically
-  }
+  // we now set _isDeviceConnected=true in onSecured callback instead
 }
 
 void SerialBLEInterface::onDisconnect(uint16_t connection_handle, uint8_t reason) {
@@ -18,6 +15,14 @@ void SerialBLEInterface::onDisconnect(uint16_t connection_handle, uint8_t reason
   }
 }
 
+void SerialBLEInterface::onSecured(uint16_t connection_handle) {
+  BLE_DEBUG_PRINTLN("SerialBLEInterface: onSecured");
+  if(instance){
+    instance->_isDeviceConnected = true;
+    // no need to stop advertising on connect, as the ble stack does this automatically
+  }
+}
+
 void SerialBLEInterface::begin(const char* device_name, uint32_t pin_code) {
 
   instance = this;
@@ -36,6 +41,7 @@ void SerialBLEInterface::begin(const char* device_name, uint32_t pin_code) {
 
   Bluefruit.Periph.setConnectCallback(onConnect);
   Bluefruit.Periph.setDisconnectCallback(onDisconnect);
+  Bluefruit.Security.setSecuredCallback(onSecured);
 
   // To be consistent OTA DFU should be added first if it exists
   //bledfu.begin();

src/helpers/nrf52/SerialBLEInterface.h

@@ -25,6 +25,7 @@ class SerialBLEInterface : public BaseSerialInterface {
   void clearBuffers() { send_queue_len = 0; }
   static void onConnect(uint16_t connection_handle);
   static void onDisconnect(uint16_t connection_handle, uint8_t reason);
+  static void onSecured(uint16_t connection_handle);
 
 public:
   SerialBLEInterface() {