nebrius/raspi-led

Control of the on-board LED from Node.js

Raspi LED

Raspi LED is part of the Raspi.js suite that provides access to the onboard status LED.

If you have a bug report, feature request, or wish to contribute code, please be sure to check out the Raspi IO Contributing Guide.

System Requirements

• Raspberry Pi Model B Rev 1 or newer (sorry Model A users)
• Raspbian Jessie or newer
  • Node-RED works, but can be finicky and difficult to debug.
  • See nebrius/raspi-io#24 for more info about support for other OSes
• Node 4.0.0 or newer

Detailed instructions for getting a Raspberry Pi ready for NodeBots, including how to install Node.js, can be found in the wiki

Installation

First, be sure that you have installed raspi.

Install with npm:

npm install raspi-led

Note: this project is written in TypeScript and includes type definitions in the package.json file. This means that if you want to use it from TypeScript, you don't need to install a separate @types module.

Example Usage

In TypeScript/ES6:

import { init } from 'raspi';
import { LED, ON, OFF } from 'raspi-led';

init(() => {
  const statusLed = new LED();

  // Flash the LED twice a second
  setInterval(() => {
    if (statusLed.read() == ON) {
      statusLed.write(OFF); // Turn off the status LED
    } else {
      statusLed.write(ON); // Turn on the status LED
    }
  }, 500);
});

In JavaScript:

const raspi = require('raspi');
const led = require('raspi-led');

raspi.init(() => {
  const statusLed = new led.LED();

  // Flash the LED twice a second
  setInterval(() => {
    if (statusLed.read() == led.ON) {
      statusLed.write(led.OFF); // Turn off the status LED
    } else {
      statusLed.write(led.ON); // Turn on the status LED
    }
  }, 500);
});

API

Module Constants

Constant	Description
OFF	Status value indicating the LED is off, one of the two possible return values from reads and arguments to writes
ON	Status value indicating the LED is on, one of the two possible return values from reads and arguments to writes
module	An easily consumable object for indirectly passing this module around. Intended specifically for use by Core IO (details coming soon)
	Function Property Type Description createLED() Pass through for the LED constructor

new LED()

Instantiates a new status LED instance.

Arguments: None

Instance Methods

hasLed()

Returns whether or not a supported built-in LED was found

Arguments: None

Returns: boolean

read()

Reads the current status of the LED.

Arguments: None

Returns: ON or OFF

write(value)

Turns the LED on or off.

Arguments:

Argument	Type	Description
value	ON | OFF	The LED status to set

Returns: None

License

The MIT License (MIT)

Copyright (c) Bryan Hughes bryan@nebri.us

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.