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  / / / __/ / /   / __/ / /   / / / / /_/ / / / / __/  |   /    / / / /
 / / / /___/ /___/ /___/ /___/ /_/ / _, _/ / / / /___ /   |   _/ /_/ /
/_/ /_____/_____/_____/\____/\____/_/ |_| /_/ /_____//_/|_|  /___/___/

A rewrite of the Telecortex project in NodeJS which controls APA102/SK9822 LED strips over OPC

Gifs

Video of Steamed Hams on a previous version of TeleCortex

Coverage

Performance

Our Balena image running on a Raspberry Pi 3 can control 4 channels of 300 SK9822 pixels pixels with UDP over on-board WiFi at about 200 FPS.

Setup

Option 1: Balena Cloud (Recommended)

We've created a docker image that sets up your Raspberry Pi 3B+ as an Open Pixel Control server with 4 SPI ports. The docker image is designed to run on BalenaOS. This is the recommended way of using TeleCortex if you don't need to do development on the server. Otherwise, there's a lot of messing around required.

Sign up for BalenaCloud (it's free!) and set up an application. Use its wizard to make an image with your network details.

Or you can download and configure your own image as long as it runs docker. Head over to https://www.balena.io/os/#download and get yourself a BalenaOS image.

Once the Pi(s) is running you can push an image to it by following the instructions below

Option 2: Download and run directly on Raspbian / Dietpi

With a fresh install of raspbian lite, get your raspberry pi configured with the correct locale using raspi-config. Optionally, while you're there you may wish to enable SSH, set the correct WiFi country, change the root password, and set a unique hostname.

Enable all 4 SPI ports on raspberry pi

(this can be done by editing the file on the SD card, or while the pi is on) As root, add the lines

dtparam=spi=on # this one is not necessary if you've already enabled it in raspi-config
dtoverlay=spi1-2cs

to /boot/config.txt and reboot. For more options (e.g. 5 SPI devices) and pinouts see /boot/overlays/README.

To test, ls /dev | grep spidev should show

spidev0.0
spidev0.1
spidev1.0
spidev1.1

Requirements

# Fresh pi needs update
sudo apt-get update && sudo apt-get upgrade
# Install essential tools
sudo apt-get install vim git zip python

Install Node v10 or later

Different versions of Node support different CPU architectures.

• v10 is LTS until 2020 and supports arm64, armv6l and armv7l
• v11 went EOL in 2019 and supports arm64, armv6l and armv7l
• v12 and above only supports arm64 and armv7l

This means that the version of node you should install depends on your architecture and whether you need security patches.

Option A: Package manager

Some versions of raspbian / dietpi for your pi's architecture will install node v10+ out of the box, some won't. The way to find out is

apt info nodejs | grep 'Version'

We need this version to be greater than or equal to 10. If it's not, you'll need to use option B or C, depending on your architecture, if it is, you can just install it with

sudo apt install nodejs -y

Note: sometimes, package managers will link the node binary to nodejs, not node, you could do something like

ln -s /usr/bin/node $(which nodejs)

Option B: via nodejs dist

You can determine your CPU architecture with:

uname -m

If if your architecture is armv7 or later (RPi Model >2), you want to install v12 or later

If if your architecture is armv6 (RPi Model 1, Zero), you want to install v10.

This script will install the latest node for a particular version.

NODE_VERSION='v10' # or whatever
ARCH=$(uname -m)
NODE=$(curl https://nodejs.org/dist/index.tab | grep v10 | grep linux-${ARCH} | cut -d $'\t' -f 1 | head -n 1)
curl "https://nodejs.org/dist/${NODE}/node-${NODE}-linux-${ARCH}.tar.gz" -o "node-${NODE}.tar.gz"
tar -C /usr/local -zxf "node-${NODE}.tar.gz"

Option C: via nodesource package repository (if all else fails)

You may need these build tools.

sudo apt-get install gcc g++ make cmake

This will add the nodesource repository to apt

# install node 11
curl -sL https://deb.nodesource.com/setup_11.x | sudo -E bash -
sudo apt-get install -y nodejs

check that Node works with

node -v
npm -v

Clone this repo

git clone https://github.com/Laserphile/JS-Telecortex-2-Server
cd JS-Telecortex-2-Server

Install SerialPort NodeJS Library

See: these instructions

Install, build, link

npm install
npm run build
npm link

OSX setup

This will only work as a PBX server on OSX. You need /dev/spidev... for pi-spi to work.

Balena dev setup

If you want to push to your pi without going through the pipeline. Make sure you also "enable local mode" on BalenaCloud if its a cloud image.

• npm install --global --production --unsafe-perm balena-cli

• Get the hostname of the device you want to push to with sudo balena local scan

• build and push to the device with balena push <hostname>

• Be patient, the output will just stop for about an hour with no loading screen.

• You'll know the push completed when you get to

  [Build]   [main] Successfully tagged local_image_main:latest
  [Info]    Streaming device logs...

To view the output of the main container, you can do

• balena ssh <hostname>
• then inside that session, do balena container ls to get a list of running containers. the app is likely the latest created container which means is necessary for the next step to work
• Attach to the output of the main container with balena attach $(balena container ls -lq)

Usage

Run the server with nodemon (refreshing on change)

npm start:nodemon

Run the server in dev mode (webpack does not uglify)

npm start:dev

Run the server with arguments

get a list of command line options with

npm start -- -h

spi
      --spi-clockSpeed  SPI Clock speed to use for all devices
                                                     [number] [default: 3000000]
      --spi-mode        SPI Data mode to use for all devices
                                                           [number] [default: 0]
      --spi-channels    SPI Channel information (as JSON)
    [string] [default: "{"0": {"bus": 0, "device": 0}, "1": {"bus": 0, "device":
               1}, "2": {"bus": 1, "device": 0}, "3": {"bus": 1, "device": 1}}"]

pbx
      --pbx-ports     PBX Serial port definitions for js-pixelblaze-expander
      [string] [default: "{"0": {"name": "/dev/ttyS0", "options": {"channels": {
   "0": { "capacity": 300 }, "1": { "capacity": 300 }, "2": { "capacity": 300 },
      "3": { "capacity": 300 }, "4": { "capacity": 300 }, "5": { "capacity": 300
                                                                         }}}}}"]
      --pbx-channels  PBX channel definitions for js-pixelblaze-expander
        [string] [default: "{"0": { "port": 0, "channel": 0 }, "1": { "port": 0,
  "channel": 1 }, "2": { "port": 0, "channel": 2 }, "3": { "port": 0, "channel":
      3 }, "4": { "port": 0, "channel": 4 }, "5": { "port": 0, "channel": 5 }}"]

Options:
      --version             Show version number                        [boolean]
  -d, --devType             Type of device used
                                        [choices: "PBX", "SPI"] [default: "SPI"]
  -p, --port                port used to listen for OPC commands
                                                       [number] [default: 42069]
  -b, --brightness          global brightness value (from 0.0 to 1.0)
                                                           [number] [default: 1]
  -t, --transportProtocol   OSI Transport Layer protocol with which the server
                            will listen [choices: "TCP", "UDP"] [default: "UDP"]
  -m, --middlewareProtocol  Protocol used to translate colours before sending to
                            device
  [choices: "colours2sk9822", "colours2ws2811", "colours2ws2812", "colours2rgb"]
                                                     [default: "colours2sk9822"]
  -h, --help                Show help                                  [boolean]

so, if you wanted to use a different serial port, devType and middleware, you could do:

npm start -- src/main.js -d PBX -m colours2rgb --pbx-ports '{"0": {"name": "/dev/tty.usbserial-AD025M69", "options": {"channels": { "0": { "capacity": 300 }, "1": { "capacity": 300 }, "2": { "capacity": 300 }, "3": { "capacity": 300 }, "4": { "capacity": 300 }, "5": { "capacity": 300 }}}}}'

If everything is working, you should see something like this:

🛰  UDP Server listening on port: 0.0.0.0:42069

Quick test

Before setting up an OPC client such as JS-Telecortex-2-Client, you can test that everything is working by running this command in a new terminal window on the pi:

printf "\x00\x00\x00\x03\x00\xff\x00" >/dev/udp/127.0.0.1/42069
printf "\x01\x00\x00\x03\x00\xff\x00" >/dev/udp/127.0.0.1/42069
printf "\x02\x00\x00\x03\x00\xff\x00" >/dev/udp/127.0.0.1/42069
printf "\x03\x00\x00\x03\x00\xff\x00" >/dev/udp/127.0.0.1/42069
#       |ch-|cmd|cmd_len|--colors--|
#         ^   ^       ^    ^
# ch: 3   '   |       |    |
# cmd: 0 (8bit RGB)   |    |
# cmd_len (uint16BE): 3B   |
# colours: 1 green pixel  /

This will send a UDP OPC message to localhost port 42069 that sets the first pixel on each channel (0-3) to green. For more info, Check out the OPC protocol details