A simple idotmatrix client in Node.js

About The Project

This repository is a library for communicating with an iDotMatrix device.
These devices feature either a 32x32 or 64x64 RGB LED matrix.

You can buy these devices on the AliExpress shopping website and find the Android app here: iDotMatrix.
This library was built on the work of the idotmatrix repo to reverse engineer the Bluetooth protocol. So no app is ever needed. Also this excellent Python example python3-idotmatrix-client provided inspiration.

To display images and GIFs, you must have ffmpeg in your system PATH.

Built With

• Node.js
• Noble
• Jimp

Getting Started

1. Clone the repo

git clone https://github.com/bviksoe/idotmatrix-bvi.git

2. cd to it

cd idotmatrix-bvi

3. Install packages using Node.js npm tool

npm install

4. Perform a test run...

node index.mjs auto clock --style frame

5. Install ffmpeg video utility to process displayed images and animated GIFs. Make sure the utility is available in your system path.

ffmpeg -version

Usage

Once installed, you can begin to execute commands on the iDotMatrix device. You can perform single commands, as well as running a script with multiple actions.

The syntax for running a single command is:

node index.mjs <DEVICE> <YOUR_COMMAND_LINE_ARGUMENTS>

To discover your device, it must be turned on and ready for Bluetooth pairing. Use the following <DEVICE> values to detect it.

 "auto" - This will automatically try to discover a device
 <name> - Use the full display name of the device
 <mac>  - Use a MAC address in format: 11:22:33:44:55:66:77:88

So, for just starting a regular effect on the command line, do this:

node index.mjs auto scrolltext --style marquee --text "This is a test"

While most examples shown here are single commands executed on the command line, you have the possibility to load a command file that contains multiple commands.

node index.mjs <DEVICE> @<FILENAME>

The @filename syntax will load the file and execute lines one-by-one.
Any line beginning with the # character is treated as a comment.

You can try to run the sample test file:

node index.mjs auto @scripts/test001.txt

Supported Commands

An iDotMatrix device supports a range of effects and management commands, allowing you to display images, animated GIFs and draw on the LED display like a canvas.

Command Syntax

Below is the full syntax for a command.
Remember to prefix each command with node index.mjs auto when using the command line utility.

Commands are given in kebab-case format, such as:

clear-screen
draw-pixel

Each command will take a range of options to customize the effect.

draw-pixel --pos (5,5) --color blue
scrolltext --text "This is a text" --style scrollup --speed 90

All Available Commands

The complete command list with parameters can be found here: All Commands.

Command	Description
clear-screen	Clears the screen.
draw-pixel	Draw a pixel on the screen.
draw-pixels	Draw several pixels (same color).
clock	Show the clockface effect.
scrolltext	Marquee scrolling text effect.
image	Show a static image.
gif	Show an animated GIF image.
effect	Show some built-in pixel effects.
scoreboard	Show the Scoreboard effect.
chronograph	Show the Chronograph effect.
countdown	Show the Countdown effect.
set-time	Set the system time on the device.
set-eco-mode	Enable eco friendly mode.
set-draw-mode	Set drawing mode.
test-connection	Test availablility of device.
reset-device-hard	Delete data and reset device.
screen-freeze	Freeze the screen.
screen-off	Turn the screen off.
screen-on	Turn the screen on.
set-brightness	Set the screen brightness.
flip-screen	Flip the screen up-side down.
sleep	Pause a bit (scripting).
set-var	Set a variable (scripting).
run-script	Run a JavaScript plugin (scripting).

Useful Hints

Some useful hints on scripting commands:

# Shortcut possible on default option (no --duration needed)
sleep 5

# Alternate command style (no kebab-case)
clearScreen red

# Script will loop forever
set-var loop-forever --expr 1

# Remember to quote/escape complex variable assignments
set-var my_complex_var --expr "other_var + \"more_text\""

# Use export. All commands now see hours24 option.
# Next Clock effect will be happy.
set-var hours24 --expr 1 --export

# Variables can be used as option values
set-var xyz --expr 3
sleep --duration $XYZ$

With the run-script command, you can write complex routines in a JavaScript file to control the device.
Here is an example:

await execute('clear-screen', { color: 'black' });
for (let i = 0; i < 5; i++)
  await execute('draw-pixel', { color: 'white', pos: `(${i},${i})` });
await execute('sleep', { duration: 10 });

In the script, Node.js modules fs and path, image libraries jimp and gifwrap, and objects device, options and vars are available.

Troubleshooting

Some hints in case of troubles:

• Use the latest version of Node.js (>= v22)
• Allow Node.js to build the Bluetooth library support using the pre-gyp build tool. If you opted out of pre-gyp, reinstall both Node.js and npm.
• Your PC must be equipped with a Bluetooth v4 adapter or better.
• Code was tested on Windows. Let me know of LINUX troubles.