/* 
*** CD74HC4067 16 Channel Multiplexer ***
*/

const int buttonPin = 13;  // the number of the pushbutton pin
const int led3 = 12;    // the number of the LED pin
const int led2 = 11;
const int led1 = 10;
const int led0 = 9;
//const int pwmPin = 3;

const int S0 = A0;
const int S1 = A1;
const int S2 = A2;
const int S3 = A3;

int buttonState = 0;  // variable for reading the pushbutton status
int counter=0;
//int fadeValue=0;

void setup() {
  pinMode(led3, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led1, OUTPUT);
  pinMode(led0, OUTPUT);
  pinMode(S3, OUTPUT);
  pinMode(S2, OUTPUT);
  pinMode(S1, OUTPUT);
  pinMode(S0, OUTPUT);

  pinMode(buttonPin, INPUT);
  //pinMode(pwmPin, OUTPUT);

  digitalWrite(S3,0);
  digitalWrite(S2,0);
  digitalWrite(S1,0);
  digitalWrite(S0,0);

  Serial.begin(9600); 
}

void loop() {
  // read the state of the pushbutton value:

   buttonState = digitalRead(buttonPin);

  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
  if (buttonState == HIGH) {
    // turn LED on:
    moveNext();  // ********
    delay(400);
  }
 
}

void moveNext(){
    
  if (counter < 15) counter +=  1; else counter=0;                    

  bool a = bitRead(counter, 0);   // **********************
  bool b = bitRead(counter, 1);
  bool c = bitRead(counter, 2);
  bool d = bitRead(counter, 3);

  digitalWrite(S0, a);   
  digitalWrite(S1, b);    
  digitalWrite(S2, c);
  digitalWrite(S3, d);

  digitalWrite(led0, a);   // 9     
  digitalWrite(led1, b);   // 10
  digitalWrite(led2, c);   // 11
  digitalWrite(led3, d);   // 12

  Serial.print(counter);  Serial.print(" = ");
  Serial.print(a);
  Serial.print(b);
  Serial.print(c);
  Serial.println(d);

} //////////////////////////////////////////////////////////////
















// https://drive.google.com/file/d/1PM90YH8QxyUyIX0b23-MMU2vMCeEzWcp/view