rpi-ws281x-node

Node API wrapper for the rpi_ws281x library.

Compilation

This project can be compiled using node-gyp.

$ npm install -g node-gyp
$ git clone https://github.com/dsyomichev/rpi-ws281x-node.git && cd rpi-ws281x-node
$ node-gyp configure && node-gyp build

However, it is recommended to install through npm.

Installation

You can add this package to your own project using npm.

$ npm install rpi-ws281x-node

Then load it into your own project. This project includes type declarations for Typescript.

const driver = require('rpi-ws281x-node');

Notes

• This project is intended to be compiled on a Raspberry Pi device. On unsupported platforms, an empty interface is returned.

• Root priveledges are required to acces PWM channels. Start the process as sudo.

Usage

The purpose of this project is to provide an interface between a node process and the rpi_ws281x driver. The configuration of this interface matches that of the parent library. Each property is provided via getter and/or setter, with the exception of the leds property of ws2811_channel.

driver.freq = 800000; // uint32_t;
driver.dmanum = 10; // int32_t

driver.channel[0].gpionum = 18; // int32_t
driver.channel[0].invert = 0; // int32_t
driver.channel[0].count = 100; // int32_t
driver.channel[0].strip_type = 0x00081000; // int32_t
driver.channel[0].brightness = 255; // uint8_t

driver.init();

These values will be checked through the setter to verify their validity for that particular parameter.

LEDs can be modified through the leds property. When the render method is called, the underlying buffers are copied to the driver.

driver.channel[0].leds = new UInt32Array(driver.channel[0].count).fill(0xffffff);
driver.channel[0].leds[0] = 0x000000;

driver.render();

The leds property will be checked for validity when the render method is called. It will throw an ERR_INVALID_ARG error if the property is not a Uint32Array or if the size does not match.

For more information on the structure of the driver, see index.d.ts and the usage section of the rpi_ws281x README.

Tested Devices

• Raspberry Pi 3b v1.2

License

This project is licensed under the MIT License - see the LICENSE.md file for details.