ms-gpio

Manage Raspberry Pi GPIO pins with node.js & Raspbian (Linux) OS

Setup

Raspbian OS must be preloaded/installed on Raspberry PI device. For installation refer this page

Latest version of node be installed on your Raspberry PI device, follow below steps to update node to latest version:

curl -sLS https://apt.adafruit.com/add | sudo bash
sudo apt-get install node

ms-gpio module can then be installed with npm:

npm install ms-gpio

Usage

In order to work with Raspberry PI GPIOs, node application must run under root access.

Prior to reading or writing a GPIO pin, setup operation/function must be invoked. After this, read and write operation on a pin can be performed.

GPIO pins can be accessed ; either using the Raspberry Pi physical numbering or with BCM/SoC naming scheme . This module supports Raspberry Pi(BOARD) pin scheme, that is board pin number must be passed. Please see this page for more details.

API

Methods

setup(pinNo, direction)

Sets up a pin for read or write. It must be done before the pin can be used for either reading or writing

• pinNo : Reference to the GPIO pin
• direction: Pin direction can be set to INPUT_MODE for read mode or OUTPUT_MODE for write mode. If not passed, it defaults to OUTPUT_MODE

read(pinNo)

Reads the value of a pin, returns boolean value true for high voltage (ON) & false for low voltage (OFF).

• pinNo : Reference to the GPIO pin
• error : Prior to the read operation, setup operation must be performed. Else error is thrown from the method

write(pinNo, value)

Writes the value of a pin.

• pinNo : Reference to the GPIO pin
• value : A boolean value of true for high voltage (ON) & false for low voltage (OFF) must be passed
• error : Prior to the write operation, setup operation must be performed. Else error is thrown from the method

tearDown()

Unexports all the exported pins.

Examples

Setup and read the value of a pin

var gpio = require('ms-gpio');
gpio.setUp(16, gpio.INPUT_MODE);
gpio.read(16);

Setup and write to a pin

var gpio = require('ms-gpio');
gpio.setUp(16, gpio.OUTPUT_MODE);
gpio.write(16,true); //Sets the GPIO to high
gpio.write(16,false); //Sets the GPIO to low

Tear down the exported pin

var gpio = require('ms-gpio');
gpio.tearDown();