johnny-five/lib/ir.js

The JavaScript Arduino Programming Framework.

var Board = require("../lib/board.js"),
  events = require("events"),
  util = require("util"),
  __ = require("../lib/fn.js");


var priv = new Map(),
  Devices;

Devices = {
  /**
   * Sharp GP2Y0D805Z0F IR Sensor
   * 0×20, 0×22, 0×24, 0×26
   *
   * http://osepp.com/products/sensors-arduino-compatible/osepp-ir-proximity-sensor-module/
   *
   *
   * http://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp2y0d805z_e.pdf
   *
   */

  "GP2Y0D805Z0F": {
    type: "proximity",
    address: 0x26,
    bytes: 1,
    delay: 250,

    // read request data handler
    data: function(read, data) {
      var state = priv.get(this).state,
        value = data[0],
        timestamp = new Date(),
        err = null;

      if (value !== state && value === 1) {
        this.emit("motionstart", err, timestamp);
      }

      if (state === 1 && value === 3) {
        this.emit("motionend", err, timestamp);
      }

      priv.set(this, {
        state: value
      });
    },

    // These are added to the property descriptors defined
    // within the constructor
    descriptor: {
      value: {
        get: function() {
          return priv.get(this).state;
        }
      }
    },
    setup: [
      // CRA
      [0x3, 0xFE]
    ],
    preread: [
      [0x0]
    ]
  },

  "QRE1113GR": {
    // http://www.pololu.com/file/0J117/QRE1113GR.pdf
    type: "reflect",
    address: 0x4B,
    bytes: 2,
    delay: 100,

    // read request data handler
    data: function(data) {
      var temp = {
        left: data[0],
        right: data[1]
      };

      // if ( temp.left < 200 ) {
      //   this.emit( "left", err, timestamp );
      // }

      // if ( temp.right < 200 ) {
      //   this.emit( "right", err, timestamp );
      // }


      priv.set(this, temp);
    },

    descriptor: {
      left: {
        get: function() {
          return priv.get(this).left;
        }
      },
      right: {
        get: function() {
          return priv.get(this).right;
        }
      }
    },

    setup: [
      // Reset the ADC (analog-to-digital converter)
      // NXP PCA969
      [0x0, 0x0]
    ],
    preread: [
      // left, right
      [0x0, 0x1]
    ]
  }
};



function IR(opts) {

  if (!(this instanceof IR)) {
    return new IR(opts);
  }

  var address, bytes, data, device, delay, descriptor,
    last, properties, preread, read, setup;

  // Initialize a Device instance on a Board
  Board.Device.call(
    this, opts = Board.Options(opts)
  );

  device = Devices[opts.device];

  address = opts.address || device.address;
  bytes = device.bytes;
  data = device.data;
  delay = device.delay;
  setup = device.setup;
  descriptor = device.descriptor;
  preread = device.preread;

  // Read event throttling
  this.freq = opts.freq || 500;

  // Make private data entry
  priv.set(this, {
    state: 0
  });

  // Set up I2C data connection
  this.io.sendI2CConfig();

  // Enumerate and write each set of setup instructions
  setup.forEach(function(byteArray) {
    this.io.sendI2CWriteRequest(address, byteArray);
  }, this);

  // Read Request Loop
  setInterval(function() {
    // Set pointer to X most signficant byte/register
    this.io.sendI2CWriteRequest(address, preread);

    // Read from register
    this.io.sendI2CReadRequest(address, bytes, data.bind(this));

  }.bind(this), delay);

  // Continuously throttled "read" event
  setInterval(function() {
    // @DEPRECATE
    this.emit("read");
    // The "read" event has been deprecated in
    // favor of a "data" event.
    this.emit("data");
  }.bind(this), this.freq);

  if (descriptor) {
    Object.defineProperties(this, descriptor);
  }
}

util.inherits(IR, events.EventEmitter);

module.exports = IR;