johnny-five/wip/ps3.js

The JavaScript Arduino Programming Framework.

"use strict";

var util = require("util"),
    Emitter = require("events").EventEmitter,
    HID = require("node-hid");

var READ_SPEED = 10,
    JOYSTICK_THRESHOLD = 20;

function scale(x, fromLow, fromHigh, toLow, toHigh) {
  return (x - fromLow) * (toHigh - toLow) /
    (fromHigh - fromLow) + toLow;
}

var path,
    controller;

HID.devices().forEach(function(dev) {
  if (dev.product === "PLAYSTATION(R)3 Controller") {
    path = dev.path;
  }
});

function PS3() {
  Emitter.call(this);

  if (path) {
    controller = new HID.HID(path);
  } else {
    console.log("No PS3 controller found.");
  }

  this.keysDown = {};

  controller.read(function read(error, data) {
    if (error) {
      console.error(error);
    } else {
      [this.keys.triggers.UP, this.keys.triggers.DOWN].forEach(function(key) {
        if (data[key] > 0) {
          if (!this.keysDown[key]) {
            this.keypress(key);
          }
          this.keysDown[key] = true;
        } else {
          this.keysDown[key] = false;
        }
      });

      this.throttle(data[this.keys.triggers.RIGHT_STICK_Y]);

    }


    setTimeout(read.bind(this), READ_SPEED);
  }.bind9this);
}

util.inherits(PS3, Emitter);

PS3.prototype.keypress = function(val) {
  this.emit("keypress", val);
};

PS3.prototype.throttle = function (val) {
  var temp = -(val - 128),
      throttle = 0;

  if (temp < JOYSTICK_THRESHOLD / -2 || temp > JOYSTICK_THRESHOLD / 2) {
    throttle = scale(temp, -128, 128, -20, 20);
    this.emit("throttle", throttle);
  }
};

PS3.prototype.close = function () {
  if (controller) {
    controller.close();
  }
};

PS3.keys = {
  resolution: 256,
  triggers: {
    LEFT_LK: 2,
    RIGHT_LK: 3,
    PS: 4,
    L1: 20,
    L2: 18,
    R1: 21,
    R2: 19,
    UP: 14,
    DOWN: 16,
    LEFT: 17,
    RIGHT: 15,
    TRIANGLE: 22,
    SQUARE: 25,
    CIRCLE: 23,
    CROSS: 24,
    LEFT_STICK_X: 6,
    LEFT_STICK_Y: 7,
    RIGHT_STICK_X: 8,
    RIGHT_STICK_Y: 9,
    AXIS_ROLL: 42,
    AXIS_PITCH: 44,
    WIGGLE: 46
  },
  left: {
    UP: 16,
    DOWN: 64,
    LEFT: 28,
    RIGHT: 32,
    LEFT_STICK: 2,
    RIGHT_STICK: 4,
    SELECT: 1,
    START: 8
  },
  right: {
    L1: 4,
    L2: 1,
    R1: 8,
    R2: 2,
    TRIANGLE: 16,
    SQUARE: 128,
    CIRCLE: 32,
    CROSS: 64
  }
};

module.exports = PS3;