serialed.ino

int ledPin = 13;
char incoming;
bool checked  = true;
int id = 1;
bool ledState = false;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  delay(500);

  pinMode(ledPin, OUTPUT);
  state();
}

void loop() {
  // put your main code here, to run repeatedly:
  if (Serial.available() > 0) {
    incoming = Serial.read();
    checked = false;
    //Serial.println("incomgin data");
    //Serial.println(incoming);
  }
  check();
}

void check() {
  if (checked) {
    return;
  }
  if (incoming == '0') {
    off();
    state();
  }
  
  if (incoming == '1') {
    on();
    state();
  }
  
  if (incoming == '2') {
    toggle();
    state();
  }
  
  if (incoming == '3') {
    state();
  }
  
  checked = true;
}

void on() {
  digitalWrite(ledPin, HIGH);
  ledState = true;
}

void off() {
  digitalWrite(ledPin, LOW);
  ledState = false;
}

void toggle() {
  if (ledState == true) {
    off();
    return;
  }
  on();
}


void state() {
  String msg = (String) id;
  msg = "{\"id\":"+msg + ",\"state\":" + ledState + "}";
  Serial.println(msg);
}