Access Protection Authentication

I would have really liked to provide some password protection where the user would need to enter a password on the mobile phone, but somehow this does not fit with what's possible in Bluetooth. Here is a list of what you can do to protect your device somehow:

• You can activate Bluetooth Authentication by calling activate_pin_code(true). This forces the Mobile Phone to generate a pin code and send it to the ESP32. You need to confirm the password by calling confirm_pin_code(). You might want to provide a button to trigger this functionality.

BluetoothA2DPSink a2dp_sink;

void setup() {
  a2dp_sink.activate_pin_code(true);
  a2dp_sink.start("MyMusic", false);  
}

void loop() {
  // add logic which calls confirm_pin_code().
}

Here is a full working example

• You can provide a callback method which decides if a device is valid or not by calling set_address_validator()

BluetoothA2DPSink a2dp_sink;

bool check(esp_bd_addr_t adr){
  // this will prevent all connections
  return false;
}

void setup() {
  a2dp_sink.set_address_validator(check);
  a2dp_sink.start("MyMusic", false);  
}

void loop() {
}

• You can call the method set_discoverability() to prevent that the device can be discovered. This function is however only available with ESP Arduino 2.0.0

a2dp_sink.set_discoverability(ESP_BT_NON_DISCOVERABLE);

Please let me know if you managed to find some better way in the following discussion...