node-native-gpio is a sysfs General Purpose Input Output wrapper for node.js. It gives you the ability to control GPIO devices in a simple object orientated manner.
Install node-native-gpio with npm(1):
$ npm install native-gpio
var gpio = require('native-gpio'); var gpio22 = new gpio.GPIO(22); gpio22 .direction(gpio.OUT) .activeLow(gpio.LOW) .value(gpio.HIGH) .value(gpio.LOW) .value(gpio.HIGH) ;
GPIO function prototype is a C++ add-on which abstracts a GPIO device as
instancable object. There are some class constants defined which should be used
for setting values (see below).
Direction constant used to determinate that our GPIO device listens for
incoming signals. While a device is set to
IN we can only read and not write
Direction constant used to determinate that our GPIO device writes outgoing
signals. While a device is set to
OUT we can read and set the current value.
Value constant for off state of a GPIO device.
Value constant for on state of a GPIO device.
var gpio36 = new GPIO(36);
if (gpio36.direction() === GPIO.OUT) gpio36.direction(GPIO.IN);
Returns the current GPIO direction mode if no arguments supplied else it will check if the first argument is a valid constant and then will set this as GPIO direction.
if (gpio36.activeLow() === GPIO.HIGH) gpio36.activeLow(GPIO.LOW);
Some circuits use a GPIO the other way around: This means the GPIO enables the
circuit when it switches to
LOW. In order to keep semantics of value you can
switch the active mode by using
activeLow with either
while (gpio36.value() != GPIO.HIGH) // wait until GPIO value changes to HIGH // use GPIO as output device gpio36.direction(GPIO.OUT).value(GPIO.LOW);
Returns the current GPIO value if no arguments supplied else it will check if the first argument is a valid constant and then will use this as GPIO value.
Copyright © 2013 Bodo Kaiser firstname.lastname@example.org
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.