The Pleasure of Building: Rasp Pi RGB Led Web Driver

Hi, finally I have time to post program ... :)

For this first phase I made a simple program with NodeJS language that listen on local port 8000 and drive RGB led strip by simple http request with string parameters. For drive the RGB led I made simple circuit that you can read in previous post.

In my last video below, you can see final build of raspberry prototype shield that it drive a 10W RGB led lamp.

Istruction:

Install nodejs application, there are many guide on internet,
on recent raspberry OS you can install it by apt
Install with npm express and gpio library
npm install express
npm install gpio
Copy and paste the script below into a file rgbweb.js
on terminal execute <prompt>$ node rgbweb,js
Now open web browser and insert this url
"http://<IP_raspberry>:8000/Lamp/1/0/1/0/1/0"
See what happen :)

In this other video you can see how command string work

This is my first js script and I thinked that now is easy add static html page with button to send specific string command. I'm working for this but before I want look how work socket.io library ;)

Below the program server.

============ rgbweb.js ==============

//Controllo remoto via http x striscia led RGB
//Raspberry Pi2 by SgaboLab 09/2016 www.sgabolab.com

var express = require('express');
var webserver = express();
var Gpio = require('onoff').Gpio,
ledR = new Gpio(16, 'out'),
ledG = new Gpio(20, 'out'),
ledB = new Gpio(21, 'out');
var timerR, timerG, timerB

// Reset iniziale led
ledR.writeSync(Number(0));
ledG.writeSync(Number(0));
ledB.writeSync(Number(0));

webserver.get('/Lamp/:R/:G/:B/:LR/:LG/:LB', function(req, res){
// chiamata get: /Lamp/0/0/0/0/0/0 0 spento 1 acceso/lampeggiante

    if (req.params.LR == 1){
        clearInterval(timerR);
        timerR = setInterval(blinkR, 1000);
    } else {
        clearInterval(timerR);
        ledR.writeSync(Number(req.params.R));
    }

    if (req.params.LG == 1){
        clearInterval(timerG);
        timerG = setInterval(blinkG, 1000);
    } else {
        clearInterval(timerG);
        ledG.writeSync(Number(req.params.G));
    }

    if (req.params.LB == 1){
        clearInterval(timerB);
        timerB = setInterval(blinkB, 1000);
    } else {
        clearInterval(timerB);
        ledB.writeSync(Number(req.params.B));
    }

    res.send('Ricevuto');
});

// funzioni timer per colore
function blinkR() {
        var state = ledR.readSync();
        ledR.writeSync(Number(!state));
}

function blinkG() {
        var state = ledG.readSync();
        ledG.writeSync(Number(!state));
}

function blinkB() {
        var state = ledB.readSync();
        ledB.writeSync(Number(!state));
}

webserver.listen(8000);
console.log("Server running at http://127.0.0.1:8000/");

========== END rgbweb.js =============

Rasp Pi RGB Led Web Driver - Node js Script