[arduino code examples for MT4]-03 Read free GPIO state

Code:
/*

  Made by KinCony IoT: https://www.kincony.com



  Monitor GPIO0, GPIO18, GPIO8

  Print to Serial when state changes

*/



#define PIN_0   0

#define PIN_18  18

#define PIN_8   8



int lastState0;

int lastState18;

int lastState8;



void setup() {

  Serial.begin(115200);



  pinMode(PIN_0, INPUT_PULLUP);

  pinMode(PIN_18, INPUT_PULLUP);

  pinMode(PIN_8, INPUT_PULLUP);



  lastState0  = digitalRead(PIN_0);

  lastState18 = digitalRead(PIN_18);

  lastState8  = digitalRead(PIN_8);



  Serial.println("GPIO Monitor Started");

}



void loop() {



  int state0 = digitalRead(PIN_0);

  if (state0 != lastState0) {

    Serial.print("GPIO0 changed to: ");

    Serial.println(state0);

    lastState0 = state0;

  }



  int state18 = digitalRead(PIN_18);

  if (state18 != lastState18) {

    Serial.print("GPIO18 changed to: ");

    Serial.println(state18);

    lastState18 = state18;

  }



  int state8 = digitalRead(PIN_8);

  if (state8 != lastState8) {

    Serial.print("GPIO8 changed to: ");

    Serial.println(state8);

    lastState8 = state8;

  }



  delay(10);

}