#include "Arduino.h"

constexpr int eocPin        = 3;  // pin from ADC EOC to UNO//output for ADC0808, but input from Arduino
constexpr int startPin      = 2;  // pin from UNO to ADC START//input for ADC0808, but output from Arduino

void setup() {
  Serial.begin(9600);

  // Changed from INPUT to INPUT_PULLUP for Wokwi
  // The slide switches have been "modified" in diagram.json not to bounce!
  pinMode(13, INPUT_PULLUP);
  pinMode(12, INPUT_PULLUP);
  pinMode(11, INPUT_PULLUP);
  pinMode(10, INPUT_PULLUP);

  pinMode(startPin, OUTPUT);
  pinMode(eocPin, INPUT);

  // Interrupt routine that just reports that data are available
  attachInterrupt(digitalPinToInterrupt(eocPin), setDataAvailable, RISING); 
}

boolean dataAvailable = false;

void loop() {
  startADCCycle();
  handleData();
}

void startADCCycle() {
    digitalWrite(startPin, HIGH);  // set START Pin to High
    delayMicroseconds(100);
    digitalWrite(startPin, LOW);  // set START Pin to LOW again
    delayMicroseconds(100);
    digitalWrite(startPin, HIGH);  // set START Pin to High
}

void handleData() {
  if (dataAvailable) {
    dataAvailable = false;
    printData();
  }
}

void setDataAvailable() {
  dataAvailable = true;
}



void printData() {
  int pin13State = 0;
  int pin12State = 0;
  int pin11State = 0;
  int pin10State = 0;
  static int lastpin13State = 1;
  static int lastpin12State = 1;
  static int lastpin11State = 1;
  static int lastpin10State = 1;

  pin13State = digitalRead(13);
  pin12State = digitalRead(12);
  pin11State = digitalRead(11);
  pin10State = digitalRead(10);
  if (pin13State != lastpin13State || pin12State != lastpin12State || pin11State != lastpin11State || pin10State != lastpin10State)
  {
    String out = "";
    out =  (pin13State == HIGH)  ? "1" : "0";
    out += (pin12State == HIGH)  ? "1" : "0";
    out += (pin11State == HIGH)  ? "1" : "0";
    out += (pin10State == HIGH)  ? "1" : "0";
    Serial.println(out);
    lastpin13State = pin13State;
    lastpin12State = pin12State;
    lastpin11State = pin11State;
    lastpin10State = pin10State;
  }
}