ESP32 Bluetooth classic. Callback. ESP32 CAM

Juan_Antonio · June 19, 2021, 11:11pm

2.- App sends a message to ESP32.

If message contains "Set LED4 ON" then LED4 ON. Return response.
If message contains "Set LED4 OFF" then LED4 OFF. Return response.
If message contains "How are you?" then get status LED4.

#include "BluetoothSerial.h"
#define LED4 4

BluetoothSerial SerialBT;

void setup() {
  Serial.begin(115200);
  initBT();
  pinMode(LED4, OUTPUT);
}

void initBT(){
  if(!SerialBT.begin("ESP32CAM-CLASSIC-BT")){
    Serial.println("An error occurred initializing Bluetooth");
    ESP.restart();
  }else{
    Serial.println("Bluetooth initialized");
  }

  SerialBT.register_callback(btCallback);
  Serial.println("The device started, now you can pair it with bluetooth");
}

void btCallback(esp_spp_cb_event_t event, esp_spp_cb_param_t *param){
  if(event == ESP_SPP_SRV_OPEN_EVT){
    Serial.println("Client Connected!");
  }else if(event == ESP_SPP_DATA_IND_EVT){
    Serial.printf("ESP_SPP_DATA_IND_EVT len=%d, handle=%d\n\n", param->data_ind.len, param->data_ind.handle);
        String received = bluetoothReadLine();
        Serial.println(received);
        if(received.indexOf("Set LED4 ON") != -1){digitalWrite(LED4, HIGH); writeSerialBT("LED 4 is ON.");}
        else if(received.indexOf("Set LED4 OFF") != -1){digitalWrite(LED4, LOW); writeSerialBT("LED 4 is OFF.");}
        else if(received.indexOf("How are you?") != -1){
          if(digitalRead(LED4)){writeSerialBT("LED 4 now is ON.");}
          else {writeSerialBT("LED 4 now is OFF.");}
        }
        else {writeSerialBT("Message received: " + received);}
    }
}

String bluetoothReadLine(){
    String text_received = "";
    while(SerialBT.available())
    {
        byte r = SerialBT.read();
        if(r!=13 && r!=10 && char(r)!='\0')
            text_received = text_received + char(r);
    }
    return text_received;      
}


void writeSerialBT(String respuesta){
  SerialBT.println(respuesta);
  SerialBT.flush();
}


void loop() { }