ESP32 Bluetooth SPP Control Relay Board

Purpose:

“ESP32 uses BT SPP Profile to connect with mobile phones or PCs and transmit strings through BT function to perform specific functional actions for functional strings to switch relay board.”

Circuit:

Demo:

YouTube:

ESP32 code:

#include <BluetoothSerial.h>

BluetoothSerial BT;

void setup()

{

  Serial.begin(9600);

  BT.begin("BT_winson");// BTName為藍芽廣播名稱

  Serial.println(F("init"));

/**

  #ifdef ENABLE_LEDTASK

  initledTask();

  #endif

  #ifdef ENABLE_UARTTASK

  inituartTask();

  #endif

**/

}

void loop()

{

  while (BT.available())

  {

    String BTdata = BT.readString();

    BTprocessCommand(BTdata); // do something with the command

  }//while (BT.available())

}

//------------------------------------------------------------------------------

void BTprocessCommand(String data)

{

  if (data == "LED_OFF")

  {

    Serial.println(F("LED_OFF"));

    vTaskSuspend(hled);

  }

  if (data == "LED_ON")

  {

    Serial.println(F("LED_ON"));

    vTaskResume(hled);

  }

  if (data == "RELAY1_ON")

  {

    pinMode(32, OUTPUT);

    digitalWrite(32, LOW);

    Serial.println(F("RELAY1_ON"));

  }

  if (data == "RELAY1_OFF")

  {

    pinMode(32, OUTPUT);

    digitalWrite(32, HIGH);

    Serial.println(F("RELAY1_OFF"));

  }

  if (data == "RELAY2_ON")

  {

    pinMode(33, OUTPUT);

    digitalWrite(33, LOW);

    Serial.println(F("RELAY2_ON"));

  }

  if (data == "RELAY2_OFF")

  {

    pinMode(33, OUTPUT);

    digitalWrite(33, HIGH);

    Serial.println(F("RELAY2_OFF"));

  }

  if (data == "RELAY3_ON")

  {

    pinMode(25, OUTPUT);

    digitalWrite(25, LOW);

    Serial.println(F("RELAY3_ON"));

  }

  if (data == "RELAY3_OFF")

  {

    pinMode(25, OUTPUT);

    digitalWrite(25, HIGH);

    Serial.println(F("RELAY3_OFF"));

  }

  if (data == "RELAY4_ON")

  {

    pinMode(26, OUTPUT);

    digitalWrite(26, LOW);

    Serial.println(F("RELAY4_ON"));

  }

  if (data == "RELAY4_OFF")

  {

    pinMode(26, OUTPUT);

    digitalWrite(26, HIGH);

    Serial.println(F("RELAY4_OFF"));

  }

}