android-esp32-ble

This serves as a project template for a bluetooth le connection between an ESP32 and an android app.

features:

• ESP32 BLE uart server
  • easy usage with sendMessage(String message) and messageHandler(String message) functions
• Android App template
  • checking for permissions before start and requesting them with dialog
  • scans for nearby devices
  • connect to BLE devices
  • easy usage with writeCharacteristic(message: String) and messageHandler: (String) -> Unit functions

components

ESP32

The ESP32 acts as BLE server and provides a services with two characteristics. In the messageHandler the code to handle incomming messages has to be inserted:

void  messageHandler(String  message)
{
    // ADD YOUR CODE HERE
    Serial.println(message);
}

To send a message void sendMessage(String message) can be called. Then the characteristic will be updated and the android app will be notified.

Android

The android app scans for bluetooth devices. After connection to the ESP32 incoming messages can be handled with a messageHandler function:

	private fun messageHandler(message: String) {
		// ADD MESSAGE HANDLER HERE
		println("Message handler: " + message)
	}

To send a message writeCharacteristic(message: String) can be called.

credits

Based on ESP_UART by https://wiki.hackerspace-bremen.de/sonstiges/tutorials/esp32/bluetooth_le_-_uart