garageWithButtonInput.js

/* -----------------------------                                                
  AUTHOR:  @SEYAM
  seyam.bd.net@gmail.com
------------------------------ */


var mraa = require('mraa');
console.log('MRAA Version: ' + mraa.getVersion());

var led = new mraa.Gpio(13);
var button = new mraa.Gpio(2);


led.dir(mraa.DIR_OUT);
button.dir(mraa.DIR_IN);


 


const mqtt = require('mqtt');
const broker = mqtt.connect('mqtt://broker.hivemq.com');
var oldbutton = 0;
var state = 'closed';
var cstate =0;




// function checkState(){

//     var reading = button.read();
//     console.log('Button state= '+reading);

//     if(reading == 1 && prevState == 0){
//         led.write(1);
//         prevState = 1;
                    
//     }
//     else{
//         led.write(0);
//     }

    
//     setTimeout(checkState, 250);
// }

checkState();

function checkState(){

  var reading = button.read();
  console.log('Button state= '+reading);

    if(reading && !oldbutton) // same as if(button == high && oldbutton == low)
      {
        //we have a new button press
        if(cstate == 0) // if the state is off, turn it on
        {
          led.write(1);
          cstate = 1;
          sendStateUpdate()
        }
        else // if the state is on, turn it off
        {
          led.write(0);
          cstate = 0;
          sendStateUpdate()
        }
        oldbutton = 1;
      }
      else if(!reading && oldbutton) // same as if(button == low && oldbutton == high)
      {
        // the button was released
        oldbutton = 0;
      }
      setTimeout(checkState, 250);
}








/**
 * The state of the garage, defaults to closed
 * Possible states : closed, opening, open, closing
 */
//var state = 'closed'

broker.on('connect', () => {  
  broker.subscribe('garage/open')
  broker.subscribe('garage/close')

  // Inform controllers that garage is connected
  broker.publish('garage/connected', 'true')
  sendStateUpdate()
})

broker.on('message', (topic, message) => {  
  console.log('received message %s %s', topic, message)
  switch (topic) {
    case 'garage/open':
      return handleOpenRequest(message)
    case 'garage/close':
      return handleCloseRequest(message)
  }
})

function sendStateUpdate () {  
  console.log('sending state %s', state)
  broker.publish('garage/state', state)
}

function handleOpenRequest (message) {  
  if (state !== 'open' && state !== 'opening') {

    led.write(1);

    console.log('opening garage door')
    state = 'opening'
    sendStateUpdate()

    // simulate door open after 5 seconds (would be listening to hardware)
    setTimeout(() => {
      state = 'open'
      sendStateUpdate()
    }, 5000)
  }
}

function handleCloseRequest (message) {  
  if (state !== 'closed' && state !== 'closing') {

    led.write(0);

    state = 'closing'
    sendStateUpdate()

    // simulate door closed after 5 seconds (would be listening to hardware)
    setTimeout(() => {
      state = 'closed'
      sendStateUpdate()
    }, 5000)
  }
}










/**
 * Want to notify controller that garage is disconnected before shutting down
 */
// function handleAppExit (options, err) {  
//   if (err) {
//     console.log(err.stack)
//   }

//   if (options.cleanup) {
//     broker.publish('garage/connected', 'false')
//   }

//   if (options.exit) {
//     process.exit()
//   }
// }

/**
 * Handle the different ways an application can shutdown
 */
// process.on('exit', handleAppExit.bind(null, {  
//   cleanup: true
// }))
// process.on('SIGINT', handleAppExit.bind(null, {  
//   exit: true
// }))
// process.on('uncaughtException', handleAppExit.bind(null, {  
//   exit: true
// }))