johnny-five/eg/handclaw42.js

Firmata based Arduino Programming Framework.

var five = require("../lib/johnny-five.js"),
    http = require("http"),
    socket = require("socket.io"),
    fs = require("fs"),
    app, board, io;

function handler( req, res ) {
  var path = __dirname;

  if ( req.url === "/" ) {
    path += "/handclaw42.html";
  } else {
    path += req.url;
  }

  fs.readFile( path, function( err, data ) {
    if ( err ) {
      res.writeHead( 500 );
      return res.end( "Error loading " + path );
    }

    res.writeHead( 200 );
    res.end( data );
  });
}

app = http.createServer( handler );
app.listen( 8080 );

io = socket.listen( app );
io.set( "log level", 1 );

board = new five.Board();

board.on("ready", function() {
  var defs, servos;

  // http://www.ranchbots.com/robot_arm/images/arm_diagram.jpg
  defs = [
    // Pivot/Rotator
    { id: "rotator", pin:  6, range: [  10, 170 ], startAt: 90 },
    // Shoulder
    { id: "shoulder", pin:  9, range: [ 20, 150 ], startAt: 90 },
    // Elbow
    { id: "elbow", pin: 10, range: [  10, 120 ], startAt: 90 },
    // Wrist
    { id: "wrist", pin: 11, range: [  10, 170 ], startAt: 40 },
    // Grip
    { id: "claw", pin: 12, range: [  10, 170 ], startAt: 0 }
  ];

  // Reduce the des array into an object of servo instances,
  // where the servo id is the property name
  servos = defs.reduce(function( accum, def ) {
    return (accum[ def.id ] = five.Servo( def )) && accum;
  }, {});

  io.sockets.on( "connection", function( socket ) {
    defs.forEach(function( key ) {
      socket.emit("createServo", {
        id: key.id,
        min: key.range[0],
        max: key.range[1]
      });
    });
    socket.on("range", function( data ) {
      servos[ data.id ].move( data.value );
    });
  });
});