Controlling an LED on an Arduino over HTTP

JavaScript Meets Hardware

2013-02-05 Updated 2025-12-31 · 1f8c246

Prerequisites

Node.js and npm installed with some knowledge of Node
Arduino IDE installed on your machine
Knowledge of getting an LED working on pin 13 of an Arduino

Setting Up the Arduino

Wire an LED to pin 13 on the Arduino and plug the Arduino into your development machine. Then follow the instructions on the johnny-five readme to get your Arduino ready for communication.

Prototype setup

Setting Up the Project

Create a folder for your project and create two files in it, server.js and index.html.

Copy the code from the gist into the respective files and run the following commands in the project folder to install the dependencies:

npm install narf johnny-five

Now run your server:

node server.js

And browse to http://localhost:8079/index.html

Web interface screenshot

If you wish to control the light from another machine you will have to edit the urls in index.html and replace localhost with the IP address of the server.

How It Works

The code is quite simple, I suggest reading through it along with the johnny-five documentation to get a better understanding of what is going on.

Originally posted on Blogspot