AUTOMATIC DOOR OPENER CONTROLLED THROUGH SLACK

We have to send the signal programmatically and for that we preferred to use NodeJS.

Installing nodejs

Install required packages. Write the commands below on RPi SSH Session, this will take some time.

wget http://node-arm.herokuapp.com/node_latest_armhf.deb

sudo dpkg -i node_latest_armhf.deb

Now we have NodeJS installed on our RPi.

pi-gpio pi-gpio is a NodeJS library to access GPIO ports on RPi. Install it with following commands.

git clone git://github.com/quick2wire/quick2wire-gpio-admin.git<br>cd quick2wire-gpio-admin

make

sudo make install

sudo adduser $USER gpio

Great! Now we can control our GPIO ports on RPi, which means we are able to set a port to have 5V. We choose the GPIO port that we've connected our relay to – thanks to that we will be able to send the signal(because signal for relay means giving 5V to R1/R2 on relay board).

Trying relay control

Let's try to control our relay programmatically. Create a directory and inside it install pi-gpio's required packages

npm install pi-gpio

Now open node console by typing this.

node
var gpio = require("pi-gpio");
var pin = 11;
gpio.close(pin);

gpio.open(pin, "output", function(err) {     // Open pin 16 for output
    gpio.write(pin, 1, function() {});
});
gpio.write(pin, 0, function() {
  gpio.write(pin, 1, function() {});
});

You should hear a click sound coming from your relay. If you don't hear it, please check the connections, and pin configuration.

Step 4: Slack

Now it's time to invoke our openDoor function from Slack.

function openDoor(){
  console.log('open called');
  gpio.write(pin, 0, function() {});
  setTimeout(function() {
    gpio.write(pin, 1, function() {});
  }, (1 * 1000));
}

Connecting our device to Slack is very good, because it is a chat application and has user statuses. By using this we will able to track our device status – whether it is working or it has failed due to some problems. Heartbeat is really good option for IoT devices.

Let's create an application that connects to Slack. First you have to create a bot for your door opener. Then install required packages

npm install slack-client

Create a js file, and put the following code inside it. Do not forget to change the token that you've gathered from your bot. Then run “node app.js” – you should see ‘Welcome to Slack' message, and you also should see your bot on Slack

var Slack = require('slack-client');
var token = 'SLACK_TOKEN', // Add a bot at  https://my.slack.com/services/new/bot and copy the token here.
    autoReconnect = true,
    autoMark = true;
var slack = new Slack(token, autoReconnect, autoMark);
slack.on('open', function() {
  var unreads = slack.getUnreadCount();
  console.log('Welcome to Slack. You are @%s of %s', slack.self.name, slack.team.name);
});

slack.on('error', function(error) {
  console.error('Error: %s', error);
});

slack.login();

Now when open message arrives, call openDoor function.

slack.on('message', function(message) {
      var type = message.type,
      channel = slack.getChannelGroupOrDMByID(message.channel),
      user = slack.getUserByID(message.user),
      time = message.ts,
      text = message.text,
      response = '';

  if (user === undefined){
    /* skip channel messages(skip the messages which are not sent to sesame directly) */
    return true;
  }
  console.log('Received: %s %s @%s %s "%s"', type, (channel.is_channel ? '#' : '') + channel.name, user.name, time, text);

  if (type === 'message') {
    if (text === 'open'){
      openDoor(doorTimeout);
      response = 'ok';
      channel.send(response);
      console.log('@%s responded with "%s"', slack.self.name, response);
    }
  }
});

Step 5: Complete code

var gpio = require("pi-gpio");

var pin = 11;

var Slack = require('slack-client');
var token = 'SLACK_TOKEN', // Add a bot at https://my.slack.com/services/new/bot and copy the token here.
    autoReconnect = true,
    autoMark = true;
var slack = new Slack(token, autoReconnect, autoMark);
slack.on('open', function() {
  var unreads = slack.getUnreadCount();
  console.log('Welcome to Slack. You are @%s of %s', slack.self.name, slack.team.name);
});

/* gpio */
gpio.close(pin);                     // Close pin 16

gpio.open(pin, "output", function(err) {

 // Open pin 16 for output
    gpio.write(pin, 1, function() {});
});

/* Slack */
slack.on('message', function(message) {
  var type = message.type,
      channel = slack.getChannelGroupOrDMByID(message.channel),
      user = slack.getUserByID(message.use

r),
      time = message.ts,
      text = message.text,
      response = '';

  if (user === undefined){
    /* skip channel messages(skip the messages which are not sent to sesame directly) */
    return true;
  }
  console.log('Received: %s %s @%s %s "%s"', type, (channel.is_channel ? '#' : '') + channel.name, user.name, time, text);

  if (type === 'message') {

    if (text === 'open'){
      openDoor(doorTimeout);
      response = 'ok';
      channel.send(response);
      console.log('@%s responded with "%s"', slack.self.name, response);
    }
  }
});

slack.on('error', function(error) {
  console.error('Error: %s', error);
});

slack.login();
/* /slack */

function openDoor(){
  console.log('open called');
  gpio.write(pin, 0, function() {});
  setTimeout(function() {
    gpio.write(pin, 1, function() {});
  }, (1 * 1000));
}

Step 6: Last step: Wiring

sudo npm -g install forever

### BEGIN INIT INFO<br># Provides:             sesame
# Required-Start:
# Required-Stop:
# Default-Start:        2 3 4 5
# Default-Stop:         0 1 6
# Short-Description:    Sesame
### END INIT INFO

case "$1" in
  start)
    su pi -c 'forever start -p /home/pi/.forever /home/pi/sesame/app.js'
    ;;
  stop)
    su pi -c 'forever stopall'
    ;;
  *)

  echo "Usage: /etc/init.d/sesame {start|stop}"
  exit 1
  ;;
esac
exit 0

sudo cp sesame /etc/init.d
sudo chmod 755 /etc/init.d/sesame
sudo update-rc.d sesame defaults