odroid-gpio

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

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