juangesino / express-gpio-rest-api

Express server for a RESTful API to access the Raspberry Pi's GPIO pins.

Express GPIO RESTful API

Express server script for a RESTful API to access the Raspberry Pi's GPIO pins.

Turn pins on and off by sending GET requests to the Raspberry Pi.

Installation

First, make sure you have node.js and npm installed.

If you don't, open a terminal and type:

sudo apt-get install nodejs npm node-semver

Now we need to allow your user to access the GPIO pins (can only be done from root by default). We are going to use GPIO Admin for that:

git clone git://github.com/juangesino/quick2wire-gpio-admin.git
cd quick2wire-gpio-admin
make
sudo make install
sudo adduser $USER gpio

Logout and login again (more info).

Now we are ready to clone the server.

git clone https://github.com/juangesino/express-gpio-rest-api.git
cd express-gpio-rest-api
npm install

To run the script:

node app.js

Usage

The server has 3 simple routes:

GET /on/:pin_number
GET /off/:pin_number
GET /blink/:pin_number/:time_in_milliseconds

The first method just sets the pin HIGH.

The second method sets the pin LOW.

The third method sets the pin HIGH, waits the number of milliseconds you requested and then sets the pin LOW.

The server script uses the node.js library pi-gpio. This library uses the physical pin numbering (the 'Pin#' in the image bellow) for the GPIO pins:

For more information about what pins to use please go to the pi-gpio docs.

Examples

The server runs by default on port 3000 (you can change this on the app.js file).

The requests should be done to the Raspberry Pi's IP address (e.g.: 192.168.0.10:3000).

Turn pin 12 on

GET /on/12

Turn pin 12 off

GET /off/12

Turn pin 12 on for 2 seconds, then turn off

GET /blink/12/2000

Contributing

1. Fork it ( https://github.com/juangesino/express-gpio-rest-api/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

TODO

• Read pins.
• Check for bad params.
• GET request should show the pin state and PUT should be used to change state.
• Blink a given number of times.
• Inverse blink (turn off, wait, turn on).
• Write tests.

License

See MIT-LICENSE