Arduino R4 & BLE

MIT App Inventor Help
,
1

I connected the Arduino Rev 4 to App inventor , the connection and disconnection works well but the sending of data doesn't work, nothing happens, why?
Thanks

#include <ArduinoBLE.h>

BLEService ledService("19B10000-E8F2-537E-4F6C-D104768A1214"); // create service

// create switch characteristic and allow remote device to read and write
BLEByteCharacteristic switchCharacteristic("19B10001-E8F2-537E-4F6C-D104768A1214", BLERead | BLEWrite);

const int ledPin = LED_BUILTIN; // pin to use for the LED

void setup() {
  Serial.begin(9600);
  while (!Serial);
  
  pinMode(ledPin, OUTPUT); // use the LED pin as an output

  // begin initialization
  if (!BLE.begin()) {
    Serial.println("starting Bluetooth® Low Energy module failed!");

    while (1);
  }

  // set the local name peripheral advertises
  BLE.setLocalName("LEDCallback");
  // set the UUID for the service this peripheral advertises
  BLE.setAdvertisedService(ledService);

  // add the characteristic to the service
  ledService.addCharacteristic(switchCharacteristic);

  // add service
  BLE.addService(ledService);

  // assign event handlers for connected, disconnected to peripheral
  BLE.setEventHandler(BLEConnected, blePeripheralConnectHandler);
  BLE.setEventHandler(BLEDisconnected, blePeripheralDisconnectHandler);

  // assign event handlers for characteristic
  switchCharacteristic.setEventHandler(BLEWritten, switchCharacteristicWritten);
  // set an initial value for the characteristic
  switchCharacteristic.setValue(0);

  // start advertising
  BLE.advertise();

  Serial.println(("Bluetooth® device active, waiting for connections..."));
}

void loop() {
  // poll for Bluetooth® Low Energy events
  BLE.poll();
}

void blePeripheralConnectHandler(BLEDevice central) {
  // central connected event handler
  Serial.print("Connected event, central: ");
  Serial.println(central.address());
}

void blePeripheralDisconnectHandler(BLEDevice central) {
  // central disconnected event handler
  Serial.print("Disconnected event, central: ");
  Serial.println(central.address());
}

void switchCharacteristicWritten(BLEDevice central, BLECharacteristic characteristic) {
  // central wrote new value to characteristic, update LED
  Serial.print("Characteristic event, written: ");

  if (switchCharacteristic.value()) {
    Serial.println("LED on");
    digitalWrite(ledPin, HIGH);
  } else {
    Serial.println("LED off");
    digitalWrite(ledPin, LOW);
  }
  Serial.println(switchCharacteristic.value());
}

BLE
BLE1602×742 231 KB

2

Just a shot in the dark, but try adding | BLENotify to the characteristic declaration. I'm thinking it could be the Arduino isn't triggering the event handler when the app writes new values?

3

Hi,

I added | BLENotify but the same problem remained.