// Master Nano Code
const int pinBtn1 = 8; const int pinBtn2 = 6;
const int pinBtn3 = 4; const int pinBtn4 = 2;
const int pinLed1 = 9; const int pinLed2 = 7;
const int pinLed3 = 5; const int pinLed4 = 3;

bool wisselRecht = true; bool seinRood = true;

void setup() {
  Serial.begin(9600);
  pinMode(pinBtn1, INPUT_PULLUP); pinMode(pinBtn2, INPUT_PULLUP);
  pinMode(pinBtn3, INPUT_PULLUP); pinMode(pinBtn4, INPUT_PULLUP);
  pinMode(pinLed1, OUTPUT); pinMode(pinLed2, OUTPUT);
  pinMode(pinLed3, OUTPUT); pinMode(pinLed4, OUTPUT);
  updateLEDs();
}

void loop() {
  if (digitalRead(pinBtn1) == LOW && !wisselRecht) {
    wisselRecht = true; Serial.println("W1R"); updateLEDs(); delay(200);
  }
  if (digitalRead(pinBtn2) == LOW && wisselRecht) {
    wisselRecht = false; Serial.println("W1A"); updateLEDs(); delay(200);
  }
  if (digitalRead(pinBtn3) == LOW && !seinRood) {
    seinRood = true; Serial.println("S1R"); updateLEDs(); delay(200);
  }
  if (digitalRead(pinBtn4) == LOW && seinRood) {
    seinRood = false; Serial.println("S1G"); updateLEDs(); delay(200);
  }
}

void updateLEDs() {
  digitalWrite(pinLed1, wisselRecht ? HIGH : LOW);
  digitalWrite(pinLed2, wisselRecht ? LOW : HIGH);
  digitalWrite(pinLed3, seinRood ? LOW : HIGH);
  digitalWrite(pinLed4, seinRood ? HIGH : LOW);
}