MATRIX Ecosystem protocol buffers for NodeJS

Package contains a static build of MATRIX protocol buffers via protobufjs 6.x.

Installation

$ npm install matrix-protos

Features

• Removes the need of passing proto paths inside applications
• Improved message API thanks to protobufjs 6.x

IMPORTANT

Please keep in mind that NodeJS protobufjs interface uses camelCase instead of snake_case. This is important if you are using the proto messages as a reference, because fields like rect_detection or delay_between_updates become rectDetection and delayBetweenUpdates respectively.

Docs & Community

• MATRIX documentation / Quickstart
• Community
• Github repo
• Examples
• MOS - A NodeJS framework for MATRIX Creator
• MATRIX-CLI - MOS Command line

Quick Start

NodeJS proto message usage is provided via protobufjs 6.x library, so make sure you check out the documentation.

You can find the code of the following examples in the MATRIX MALOS repo

MATRIX MALOS protocol is an abstraction layer built on top of ZeroMQ that uses protocol buffers as the data exchange format. In a nutshell, MALOS exposes 4 ports for every service: base or driver port, error port, keep alive port and data update port. In the following examples, we will show how to send a config to the driver port and how to obtain data updates on the data update port.

Please refer to the examples for a complete implementation.

Importing ZMQ and matrix-proto modules

var zmq = require('zmq')

// Import MATRIX Proto messages
var matrix_io = require('matrix-protos').matrix_io

Getting data about the available drivers and ports

Go to the full code

var requestSocket = zmq.socket('req')

var creator_ip = process.env.CREATOR_IP || '127.0.0.1';
var creator_info_base_port = 20012

requestSocket.on('message', (buffer) => {
    var msg_inst = matrix_io.malos.v1.driver.MalosDriverInfo.decode(buffer)
    console.log(msg_inst)
    process.exit(0)
});

requestSocket.connect('tcp://' + creator_ip + ':' + creator_info_base_port)
requestSocket.send('');

The output should more or less look like this:

$ node test_driver_info.js
MalosDriverInfo {
  info:
   [ DriverInfo {
       driverName: 'IMU',
       basePort: 20013,
       providesUpdates: true,
       delayBetweenUpdates: 2000,
       needsPings: true,
       timeoutAfterLastPing: 6000,
       notesForHuman: 'Provides yaw/pitch/roll. Check Imu message (protocol buffer)' },
     DriverInfo {
       driverName: 'Humidity',
       basePort: 20017,
       providesUpdates: true,
       delayBetweenUpdates: 2000,
       needsPings: true,
       timeoutAfterLastPing: 6000,
       notesForHuman: 'Provides humidity and temperature. Check Humidity message (protocol buffer)' },
     DriverInfo {
       driverName: 'Everloop',
       basePort: 20021,
       delayBetweenUpdates: 1000,
       timeoutAfterLastPing: 5000,
       notesForHuman: 'Write-only. There are 35 leds. Values range from 0 to 255. Check message EverloopImage (protocol buffer)' },
     DriverInfo {
       driverName: 'Pressure',
       basePort: 20025,
       providesUpdates: true,
       delayBetweenUpdates: 2000,
       needsPings: true,
       timeoutAfterLastPing: 6000,
       notesForHuman: 'Provides barometer/altimeter and temperature. Check Pressure message (protocol buffer)' },
     DriverInfo {
       driverName: 'UV',
       basePort: 20029,
       providesUpdates: true,
       delayBetweenUpdates: 2000,
       needsPings: true,
       timeoutAfterLastPing: 6000,
       notesForHuman: 'Provides UV index. Check UV index message (protocol buffer). Also provides a string with the UV risk according to the OMS. See: https://www.epa.gov/sunsafety/uv-index-scale-0' },
     DriverInfo {
       driverName: 'MicArray_Alsa',
       basePort: 20037,
       delayBetweenUpdates: 1000,
       timeoutAfterLastPing: 6000,
       notesForHuman: 'Simple ALSA Driver for MATRIX Creator Microphone Array' },
     DriverInfo {
       driverName: 'Lirc',
       basePort: 20041,
       delayBetweenUpdates: 1000,
       timeoutAfterLastPing: 5000,
       notesForHuman: 'Write-read. Get list remotes and send commands via IR. In development' },
     DriverInfo {
       driverName: 'Servo',
       basePort: 20045,
       delayBetweenUpdates: 1000,
       timeoutAfterLastPing: 5000,
       notesForHuman: 'Write-read. Servo handler. In development' },
     DriverInfo {
       driverName: 'Gpio',
       basePort: 20049,
       delayBetweenUpdates: 250,
       timeoutAfterLastPing: 2000,
       notesForHuman: 'Write-read. Gpio handler. In development' } ] }

You can then use the basePort in the examples below.

Configuring and reading the pressure sensor

Go to the full code

# Configure the driver (base port) socket
var configSocket = zmq.socket('push')
configSocket.connect('tcp://' + creator_ip + ':' + creator_pressure_base_port)

// Now prepare valid configuration and send it.
var config = matrix_io.malos.v1.driver.DriverConfig.create({
  delayBetweenUpdates: 2.0,  // 2 seconds between updates.
  timeoutAfterLastPing: 6.0, // Stop sending updates 6 seconds after pings.
})

configSocket.send(matrix_io.malos.v1.driver.DriverConfig.encode(config).finish())

# Configure the data update port socket
var updateSocket = zmq.socket('sub')
updateSocket.connect('tcp://' + creator_ip + ':' + (creator_pressure_base_port + 3))
updateSocket.subscribe('')

updateSocket.on('message', (buffer) => {
  var data = matrix_io.malos.v1.sense.Pressure.decode(buffer)
  console.log(data)
});

Configuring and reading the humidity sensor

Go to the full code

# Configure the driver (base port) socket
var configSocket = zmq.socket('push')
configSocket.connect('tcp://' + creator_ip + ':' + creator_humidity_base_port)

// Now prepare valid configuration and send it.
var config = matrix_io.malos.v1.driver.DriverConfig.create({
  humidity: matrix_io.malos.v1.sense.HumidityParams.create({
    currentTemperature: 23   // Real current temperature [Celsius] for calibration
  })
})

configSocket.send(matrix_io.malos.v1.driver.DriverConfig.encode(config).finish())

# Configure the data update port socket
var updateSocket = zmq.socket('sub')
updateSocket.connect('tcp://' + creator_ip + ':' + (creator_humidity_base_port + 3))
updateSocket.subscribe('')

updateSocket.on('message', (buffer) => {
  var data = matrix_io.malos.v1.sense.Humidity.decode(buffer)
  console.log(data)
});

Configuring and reading the IMU (Inertial Measurement Unit)

Go to the full code

# Configure the driver (base port) socket
var configSocket = zmq.socket('push')
configSocket.connect('tcp://' + creator_ip + ':' + creator_imu_base_port)

// Now prepare a valid configuration message and send it. The extra args in this
// example:  
//  * delayBetweenUpdates: different delay between data updates
//  * timeoutAfterLastPing: Stop sending data updates after 6 secs of the last ping
var config = matrix_io.malos.v1.driver.DriverConfig.create({
  delayBetweenUpdates: 5.0,  
  timeoutAfterLastPing: 6.0 
})

configSocket.send(matrix_io.malos.v1.driver.DriverConfig.encode(config).finish())

# Configure the data update port socket
var updateSocket = zmq.socket('sub')
updateSocket.connect('tcp://' + creator_ip + ':' + (creator_imu_base_port + 3))
updateSocket.subscribe('')

updateSocket.on('message', (imu_buffer) => {
  var imuData = matrix_io.malos.v1.sense.Imu.decode(imu_buffer)
  console.log(imuData)
});

Setting the Everloop LED intensity

Go to the full code

# Configure the driver (base port) socket
var configSocket = zmq.socket('push')
configSocket.connect('tcp://' + creator_ip + ':' + creator_everloop_base_port /* config */)

var max_intensity = 50
var intensity_value = max_intensity

function setEverloop(ledValues) {
    var image = matrix_io.malos.v1.io.EverloopImage.create()
    for (var j = 0; j < 35; ++j) {
      var ledValue = matrix_io.malos.v1.io.LedValue.create(ledValues);
      image.led.push(ledValue)
    }
    var config = matrix_io.malos.v1.driver.DriverConfig.create({
      image: image
    })
    configSocket.send(matrix_io.malos.v1.driver.DriverConfig.encode(config).finish());
}

setInterval(() => {
  intensity_value -= 1
  if (intensity_value < 0)
    intensity_value = max_intensity
  setEverloop({
    red: 0,
    green: intensity_value,
    blue: 0,
    white: 0
  })
}, 50);

Using the GPIO

Go to the full code

# Configure the driver (base port) socket
var configSocket = zmq.socket('push')
configSocket.connect('tcp://' + creator_ip + ':' + creator_gpio_base_port /* config */)

// Set GPIO 0 to output mode
var gpio_cfg_cmd = matrix_io.malos.v1.io.GpioParams.create({
  pin: 0,
  mode: matrix_io.malos.v1.io.GpioParams.EnumMode.OUTPUT
})

// For demo: toggle function for output value
process.nextTick(() => { toggle =! toggle });
console.log('==> pin 0 set to:', toggle)
if (toggle) gpio_cfg_cmd.value = 1;
else gpio_cfg_cmd.value = 0;

// build and sending proto
var config = matrix_io.malos.v1.driver.DriverConfig.create({
  gpio: gpio_cfg_cmd
})
configSocket.send(matrix_io.malos.v1.driver.DriverConfig.encode(config).finish())


// Set GPIO 1 to input mode
var config = matrix_io.malos.v1.driver.DriverConfig.create({
  delayBetweenUpdates: 0.250, // 250 miliseconds between updates.
  timeoutAfterLastPing: 2.0,  // Stop sending updates 2 seconds after pings.
  gpio: matrix_io.malos.v1.io.GpioParams.create({
    pin: 1, // GPIO params: set pin 1 to input mode
    mode: matrix_io.malos.v1.io.GpioParams.EnumMode.INPUT
  })
})
configSocket.send(matrix_io.malos.v1.driver.DriverConfig.encode(config).finish())

# Configure the data update port socket
var updateSocket = zmq.socket('sub')
updateSocket.connect('tcp://' + creator_ip + ':' + (creator_gpio_base_port + 3))
updateSocket.subscribe('')

updateSocket.on('message', (gpio_buffer) => {
  var gpioData = matrix_io.malos.v1.io.GpioParams.decode(gpio_buffer)
  // output in binary format all 15 pins of GPIO
  console.log('<== GPIO pins register: ', dec2bin(gpioData.values))
});