node-blink1-async

Programmatically controlling blink(1) USB LED devices is simple using node-blink1-async. Much of the API is asynchronous (i.e., returns Promise that you can await on) and fully documented. This module has been tested on Mac, Windows 10, and Ubuntu Linux on a Raspberry Pi 4.

If you perfer a JS callback style API consider node-blink1.

Prerequisites

• Node (v12+)
• blink(1) USB led device

Ensure your blink(1) is fully functional using the blink(1) utilities.

Install

npm install https://github.com/ros2jsguy/node-blink-async

Linux Users

Your device may need libusb installed:

sudo apt install libusb-1.0-0

See node-hid's instructions for compiling from source You may find the 51-blink1.rules file useful in your device configuration process.

TypeScript Example

import {Blink1, Blink1_LEDN, BlinkRate} from '@ros2jsguy/node-blink1-async';

async function example() {
  // list all blink(1) devices
  console.log('devices; ', Blink1.devices());

  // output the version info of the default blink(1) device
  let blink1: Blink1 = new Blink1();
  console.log("version: " , await blink1.version() );

  console.log('set color: red', await blink1.setRGB(255));
  console.log('read rgb: ', await blink1.rgb(Blink1_LEDN.LEDA));
  await Blink1.delay(2000);

  console.log('Blink green at VERY_FAST rate (100 ms) for 5 seconds');
  await blink1.blink(0, 255, 0, BlinkRate.VERY_FAST);
  await Blink1.delay(5000);
  
  console.log('Blink blue at SLOW rate (1000 ms) for 5 seconds');
  await blink1.blink(0, 0, 255, BlinkRate.SLOW);
  await Blink1.delay(5000);

  console.log('Show solid yellow for 5 seconds');
  await blink1.blink(255, 255, 0);
  await Blink1.delay(5000);

  // turn off the blink(1) output
  await blink1.off();

  // access the display pattern at line-1
  console.log('Color pattern (line-1):', await blink1.readPatternLine(1));

  // clear the memory of all display patterns.
  console.log('Clearing pattern');
  await blink1.clearPattern();

  // confirm that display patterns are cleared
  console.log('Color pattern (line-1):', await blink1.readPatternLine(1));

  // close and release the blink(1) device
  await blink1.close();

  console.log('completed');
}

Developer Notes

I develop mostly in TypeScript and prefer using modern JS features when I have the option. Working directly with the node-blink1 package which has been around for awhile, felt too retro for my liking, e.g., no jsdoc, callback-based api... I mean no disrespect to the node-blink1 author(s) who's priority for backward compatibility supercedes breaking the package just to use a new wizbang language feature. While developing a robot using TypeScript on a Raspi4 I wanted to integrate an old Blink1 led from my kit into the design. That led me to creating this package that makes it easier to to asynchronously control a Blink1 LED from TypeScript.

Credits

This package uses the node-blink1 package to perform the low level control of Blink1 devices