MATRIX-Lite-JS

MATRIX Lite JS is an npm package that allows users of varying skill levels to easily program their MATRIX Device.

Roadmap

• Leds
• Sensors
  • IMU
  • Humidity
  • Pressure
  • UV
• GPIO
• Device Info
• Microphones
  • Hal Mics
  • Alsa Mics
• NFC (separate library)

Installation

Ensure you have a Raspberry Pi, attached with a MATRIX device, that's flashed with Raspbian.

1. Install MATRIX HAL

https://matrix-io.github.io/matrix-documentation/matrix-hal/getting-started/installation-package/

2. Install Node.js & Create A Project

Download and install the latest version of Node.js, using nvm (Node Version Manager)

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh | bash
. ~/.bashrc
nvm install node

mkdir myApp
cd myApp
npm init -y

3. Install matrix-lite-js

npm install @matrix-io/matrix-lite --save

Usage

Everloop

var matrix = require("@matrix-io/matrix-lite");

// Get LED count
console.log("This device has " + matrix.led.length + ' LEDs');

// A single string or object sets all LEDs
// Below are different ways of expressing a color (number values are from 0-255)
matrix.led.set('blue');
matrix.led.set('rgb(0,0,255)');
matrix.led.set('#0000ff');
matrix.led.set({r:0, g:0, b:255, w:0}); // objects can set white

// LEDs off
matrix.led.set('black');
matrix.led.set([]);
matrix.led.set();
matrix.led.set({});

// Arrays set individual LEDs
matrix.led.set(['red', 'gold', 'purple', {}, 'black', '#6F41C1', 'blue', {g:255}]);

// Arrays can simulate motion
everloop = new Array(matrix.led.length).fill({});
everloop[0] = {b:100};

setInterval(function(){
  var lastColor = everloop.shift();
  everloop.push(lastColor);
  matrix.led.set(everloop);
},50);

Sensors

var matrix = require('@matrix-io/matrix-lite');

// Sensors will update with each .read() call
var imu, uv, humidity, pressure;
setInterval(function(){
  imu = matrix.imu.read();
  uv = matrix.uv.read();
  humidity = matrix.humidity.read();
  pressure = matrix.pressure.read();
  
  console.log(imu, uv, humidity, pressure);
},50);

GPIO

var matrix = require('@matrix-io/matrix-lite');

// Read GPIO pin 0 (digital)
matrix.gpio.setFunction(0, 'DIGITAL');
matrix.gpio.setMode(0, 'input');
console.log(matrix.gpio.getDigital(0));

// Set GPIO pin 1 (digital)
matrix.gpio.setFunction(1, 'DIGITAL');
matrix.gpio.setMode(1, 'output');
matrix.gpio.setDigital(1, 'ON')

// Set GPIO pin 2 (PWM)
matrix.gpio.setFunction(2, 'PWM');
matrix.gpio.setMode(2, 'output');
matrix.gpio.setPWM({
  pin: 2,
  percentage: 25,
  frequency: 50 // min 36
});

// Set Servo Angle pin 3
matrix.gpio.setFunction(3, 'PWM');
matrix.gpio.setMode(3, 'output');
matrix.gpio.setServoAngle({
  pin: 3,
  angle: 90,
  // minimum pulse width for a PWM wave (in milliseconds)
  min_pulse_ms: 0.8
});

Info

var matrix = require("@matrix-io/matrix-lite");

// A string of the MATRIX device currently attached
console.log("The " + matrix.info.deviceType + " is attached to the pi");

// A boolean that's true, if the kernel modules are not installed
console.log("Are the Kernel Modules installed? " + matrix.info.isDirectBus);

Alsa

Microphone

npm mic is used grab our microphone data from alsa.

// Record mic input to file
var matrix = require("@matrix-io/matrix-lite");
var fs = require('fs');

var mic = matrix.alsa.mic();// use default settings
var mic = matrix.alsa.mic({ // or configure settings
  rate: '16000',
  debug: true,
  exitOnSilence: 6,
  // up to 8 channels
  channels: '1'
});

// Pipe mic data to file
var micStream = mic.getAudioStream();
var file = fs.WriteStream('output.raw');
micStream.pipe(file);

micStream.on('startComplete', function() {
  setTimeout(mic.stop, 5000);
});

mic.start();

Building Locally For Development

If you want to contribute to matrix-lite-js, below are the steps to build locally. Each step should take place on your Raspberry Pi.

Have MATRIX HAL installed

https://matrix-io.github.io/matrix-documentation/matrix-hal/getting-started/installation-package/

Download the matrix-lite-js repository

git clone https://github.com/matrix-io/matrix-lite-js

Install Node.js

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh | bash
. ~/.bashrc
nvm install 11.0.0

Install Node.js dependencies

npm install

From this point, you can treat the repository as a normal module. Any Node.js script can include it.

var matrix = require('PATH_TO_FOLDER/matrix-lite-js')

If you need to edit any C++ files in the hal-wrapper folder, use the following to compile your changes.

npm run build