Marc's mybot2.js: LEDs show distance from obstacle and bot turns, reverses or stops depending on obstacle distance

gistfile1.txt

// =======================
// Derived from the work done by @makenai on the
// SumoBot Jr
// =======================

var five = require("johnny-five");
var keypress = require('keypress');
var pixel = require("../../lib/pixel.js");

var RSTOPVAL = 93;
var LSTOPVAL = 93;

var distance = 0;
var opts = {};
var state = 1;
opts.port = process.argv[2] || "";

keypress(process.stdin);

var board = new five.Board(opts);

board.on("ready", function() {

    console.log("Control the bot with the arrow keys, and SPACE to stop.")

    var ping = new five.Ping(8);
    var left_wheel  = new five.Servo({ pin:  9, type: 'continuous' });
    var right_wheel = new five.Servo({ pin: 10, type: 'continuous'  });

    ping.on("change", function( err, value ) {
        console.log('Object is ' + this.cm + ' cm away');
	distance = this.cm;
    });

// ---------------------------------------------------------------

    strip = new pixel.Strip({
        data: 6,
        length: 4,
        board: this
    });

    var pos = 0;
    var colors = ["red", "green", "blue", "yellow", "cyan", "magenta", "white"];
    var current_color = 0;

    var blinker = setInterval(function() {

        strip.color("#000"); // blanks it out

	current_color = parseInt(distance/14);

        for (pos = 0; pos < strip.stripLength(); pos++ ) {
		strip.pixel(pos).color(colors[current_color]);
        }

	if (current_color == 1) { 
            left_wheel.to(LSTOPVAL);
            right_wheel.to(RSTOPVAL);
	}
	else if (current_color > 1 && state == 0) { 
            console.log('Forward');
	    state = 1;
            left_wheel.cw();
            right_wheel.ccw();
	}

	if (current_color == 0) { 
            console.log('Backward');
            left_wheel.ccw();
            right_wheel.cw();      
	    state = -1;
	} else if (state == -1) {
	    state = 0;
            console.log('Left');
            left_wheel.ccw();
            right_wheel.ccw();      
	}

        strip.show();
    }, 1000/2);

// ---------------------------------------------------------------

    process.stdin.resume(); 
    process.stdin.setEncoding('utf8'); 
    process.stdin.setRawMode(true); 

    process.stdin.on('keypress', function (ch, key) {

        if ( !key ) return;

        if ( key.name == 'q' ) {
            console.log('Quitting');
            process.exit();
        } else if ( key.name == 'up' ) {

            console.log('Forward');
            left_wheel.cw();
            right_wheel.ccw();

        } else if ( key.name == 'down' ) {

            console.log('Backward');
            left_wheel.ccw();
            right_wheel.cw();      

        } else if ( key.name == 'left' ) {

            console.log('Left');
            left_wheel.ccw();
            right_wheel.ccw();      

        } else if ( key.name == 'right' ) {

            console.log('Right');
            left_wheel.cw();
            right_wheel.cw();

        } else if ( key.name == 'space' ) {

            console.log('Stopping');
            left_wheel.to(LSTOPVAL);
            right_wheel.to(RSTOPVAL);

        }
    });
});

board.on("error", function(err) {
    console.log(err.message);
    process.exit();
});