Latest Zetta

app.js

var zetta = require('zetta');
var Arduino = require('./arduino');

var app = zetta();

app.name('i-heard-that'); // give the empress a name

app.expose('*'); // explore other arguments

app.load(Arduino); // load that scout in

app.observe('sound', function(microphone) {
  app.observe('lcd', function(lcd) {
    var soundStream = microphone.getStream('sound'); // .stream or .getStream?

    soundStream.on('data', function(value) {
      if (value > 160) {
        lcd.call('update', 'I heard that!');
      }
    });

    // ^^ :D :D
  });
});

app.listen(process.env.PORT || 3000);

arduino_scout.js

var util = require('util');
var Scout = require('zetta').Scout;
var SerialPort = require('serialport').SerialPort;
var Sound = require('./sound');
 
var ArduinoScout = module.exports = function(runtime) {
  Scout.call(this);
 
  this.runtime = runtime;
  this.portName = '/dev/tty.usbserial';
};
util.inherits(ArduinoScout, Scout);
 
ArduinoScout.prototype.init = function(cb){
  var self = this;
  this.runtime.implode();
 
  var port = new SerialPort(portName, function(err) {
    if(err) {
      return cb(err);
    }
 
    self.discover(Sound, port);
  });
};

sound_driver.js

//Driver is an event emitter
var Driver = require('zetta').Driver;
var util = require('util');

var Sound = module.exports = function(port){
  Driver.call(this);
  this._port = port;
};
//UUID is given to us by the Driver constructor
util.inherits(Sound, Driver);

//We added state, name, and type as functions to be called by config
//Setting up the state machine in two different places is strange
Sound.prototype.init = function(config) {
  config
    .state('ready')
    .name('Matt\'s Sound Sensor')
    .type('sound')
    //We use set to save user based stuff in the registry
    .set('Key', 'Value')
    .stream('sound', this.streamSound, { binary: true });

    var Value = this.get('Key');

    //Update the registry
    this.save();
}

Sound.prototype.streamSound = function(stream) {
  //stream passed into this function is a writable stream
  this._port.on('data', function(d) {
    stream.write(Number(d.toString()));
  });

  // or

  this._port.pipe(stream);

};

Newer app.js

var zetta = require('zetta');
var Arduino = require('./arduino');

var app = zetta();

app.name('i-heard-that');
app.expose('*');
app.load(Arduino);

app.observe(['sound', 'lcd'], function(sound, lcd) {
  var stream = sound.getStream('amplitude');

  stream.on('data', function(value) {
    if (value > 160) {
      lcd.call('update', 'I heard that!');
    }
  });
});

app.listen(process.env.PORT || 3000);

var Driver = require('zetta').Driver;
var util = require('util');

var Sound = module.exports = function(port){
  Driver.call(this);
  this._port = port;
};
util.inherits(Sound, Driver);

Sound.prototype.init = function(config) {
  config
    .state('ready')
    .name('Matt\'s Sound Sensor')
    .type('sound')
    .stream('amplitude', this.streamAmplitude);
}

Sound.prototype.streamAmplitude = function(stream) {
  var self = this;
  this._port.on('data', function(d) {
    var data = Number(d.toString());
    self.set('amplitude', data);
    stream.write(data);
  });
};