Jolt.js Combination Lock

This is a quick remix of the KeyPad Combination Lock which uses a Jolt.js to drive a motor when the correct combination is entered.

You'll Need

• A Jolt.js
• 2x Qwiic cables
• A [KeyPad](/KeyPad] *+A+Central+Locking Motor
• A Speaker

Wiring Up

Attach the KeyPad as Follows

Note: We can use all the pins on Q2 and Q3 because on those ports every pin is a GPIO. On Q0 and Q1 there are VCC and GND pins to allow more powerful loads to be controlled.

Attach the central locking motor between H2 and H3 on the terminal block. If it moves the wrong way for your use case you can easily adjust in software!

If you want audible feedback, attach a speaker between GND and H0 on the terminal block

Software

Paste the following onto the right hand side of the IDE and click the Upload button:

var code = "1234*";
var digit = 0;

function setLocked(isLocked) {
  // output red or green depending on whether we're locked or not
  digitalWrite([LED1,LED2,LED3], isLocked ? 0b100 : 0b010);
  // then two seconds later turn it off
  setTimeout(function() {
    digitalWrite([LED1,LED2,LED3], 0);
  }, 2000);
  // control our motor!
  if (isLocked == false) {
    // Pull motor one direction for 500ms
    digitalWrite([H2,H3], 2);
    setTimeout(() => digitalRead([H2,H3]), 500);
    // Now push it the other for 500ms
    setTimeout(() => digitalWrite([H2,H3], 1), 2000);
    setTimeout(() => digitalRead([H2,H3]), 2500);
  }
}

function onKey(key) {
  var ch = "123A456B789C*0#D"[key];
  // check against our code
  if (ch == code[digit]) {
    digit++; // go to next digit
    if (digit >= code.length) {
      console.log("We're at the end of the code - unlock!");
      digit = 0; // and go to the begining of the code again
      beep(4000, 1000); // show we're unlocked
      return setLocked(false);
    } else {
      console.log("Digit correct - next digit!");
    }
  } else {
    console.log("Wrong! Go back to the start");
    setLocked(true);
    digit = 0;
  }
  beep(4000);
}

function beep(freq,len) {
  len = len||100;
  H0.pwm(0.5,{freq:freq});
  return new Promise(resolve => setTimeout(() => {
    H0.read();
    resolve();
  }, len));
}

require("KeyPad").connect(
  [Q3.vcc,Q3.gnd,Q3.sda,Q3.scl],
  [Q2.gnd,Q2.vcc,Q2.sda,Q2.scl], onKey);

Now if you enter 1234* the lock will unlock, but any other keycode will have no effect. To change the code, just change code at the top of the program code.