odroid-gpio

odroid-gpio is a simple node.js based library to help access the GPIO of the Odroid C1 and Odroid C2.

var gpio = require("odroid-gpio");

gpio.open(16, "output", function(err) {		// Open pin 16 for output
	gpio.write(16, 1, function() {			// Set pin 16 high (1)
		gpio.close(16);						// Close pin 16
	});
});

Pin configuration

You can use the physical numbering:

Requirement: gpio-admin

The GPIO pins require you to be root to access them. That's totally unsafe for several reasons. To get around this problem, you should use the excellent gpio-admin.

Do the following on your raspberry pi:

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

replaceing $USER your username.

After this, you will need to logout and log back in.

Usage

.open(pinNumber, [options], [callback])

Aliased to .export

Makes pinNumber available for use.

pinNumber: The pin number to make available. Remember, pinNumber is the physical pin number on the Pi.
options: (Optional) Should be a string, such as input or input pullup. You can specify whether the pin direction should be input or output (or in or out). You can additionally set the internal pullup / pulldown resistor by sepcifying pullup or pulldown (or up or down). If options isn't provided, it defaults to output. If a direction (input or output) is not specified (eg. only up), then the direction defaults to output.
callback: (Optional) Will be called when the pin is available for use. May receive an error as the first argument if something went wrong.

.close(pinNumber, [callback])

Aliased to .unexport

Closes pinNumber.

pinNumber: The pin number to close. Again, pinNumber is the physical pin number on the Pi.
callback: (Optional) Will be called when the pin is closed. Again, may receive an error as the first argument.

.setDirection(pinNumber, direction, [callback])

Changes the direction from input to output or vice-versa.

pinNumber: As usual.
direction: Either input or in or output or out.
callback: Will be called when direction change is complete. May receive an error as usual.

.getDirection(pinNumber, [callback])

Gets the direction of the pin. Acts like a getter for the method above.

pinNumber: As usual
callback: Will be called when the direction is received. The first argument could be an error. The second argument will either be in or out.

.read(pinNumber, [callback])

Reads the current value of the pin. Most useful if the pin is in the input direction.

pinNumber: As usual.
callback: Will receive a possible error object as the first argument, and the value of the pin as the second argument. The value will be either 0 or 1 (numeric).

Example:

gpio.read(16, function(err, value) {
	if(err) throw err;
	console.log(value);	// The current state of the pin
});

.write(pinNumber, value, [callback])

Writes value to pinNumber. Will obviously fail if the pin is not in the output direction.

pinNumber: As usual.
value: Should be either a numeric 0 or 1. Any value that isn't 0 or 1 will be coerced to be boolean, and then converted to 0 (false) or 1 (true). Just stick to sending a numeric 0 or 1, will you? ;)
callback: Will be called when the value is set. Again, might receive an error.

Misc

To run tests: npm install && npm test where you've got the checkout.
This module was created, git push'ed and npm publish'ed all from the Raspberry Pi! The Pi rocks!

Inspiration

This lib is inspired by pi-gpio.

MIT License

legionaryu / odroid-gpio