#include <Toggle.h>

const byte but1 = 2;
const byte but2 = 3;
const byte but3 = 4;
const byte but4 = 5;

byte butState = 0;

Toggle b1(but1);
Toggle b2(but2);
Toggle b3(but3);
Toggle b4(but4);

void setup() {
  pinMode(12, OUTPUT);
  b1.begin(but1);
  b2.begin(but2);
  b3.begin(but3);
  b4.begin(but4);
}

void loop() {
  b1.poll();
  b2.poll();
  b3.poll();
  b4.poll();

  if (b1.onPress()) {
    if (butState == 0b00000000) butState |= 0b00000001;
    else clr();
  }
  if (b2.onPress()) {
    if (butState == 0b00000001) butState |= 0b00000010;
    else clr();
  }
  if (b3.onPress()) {
    if (butState == 0b00000011) butState |= 0b00000100;
    else clr();
  }
  if (b4.onPress()) {
    if (butState == 0b00000111) butState |= 0b00001000;
    else clr();
  }
  if (butState == 0b00001111) {
    digitalWrite(12, HIGH);
    butState = 0;
  }
}

void clr() {
  butState = 0;
  digitalWrite(12, LOW);
}