LED Matrix Monitoring

LED Matrix Monitoring (led_matrix_monitoring) is a system metrics visualization service for the Framework Laptop 16 LED Matrix Input Module, developed by community member Igor (GitHub: night-crawler). Written in Rust, it collects system metrics — CPU usage, memory, disk I/O, network, temperature, and battery — renders them as PNG images, and sends them to the companion LED Matrix Daemon for display on the 9x34 LED matrix¹.

The project consists of two components: the monitoring service (led_matrix_monitoring) that collects and renders metrics, and the daemon (led_matrix_daemon) that manages serial communication with the LED matrix hardware and accepts images via Unix socket or TCP¹².

Features

Metric Collectors

Metric	Description
CPU usage	Per-core and average CPU utilization
Memory usage	Percentage of RAM used
Disk I/O	Disk read/write activity
Network	Network throughput
CPU Temperature	Processor temperature readings
Battery Level	Current battery charge percentage

Widgets

The monitoring service renders several widget types onto the 9x34 pixel LED matrix¹:

Widget	Description
CPU bar	Per-core usage bar with average
Memory bar	RAM usage as a horizontal bar
Network/disk plot	Time-series plot of network and disk activity
Temperature bar	CPU temperature as a bar graph
Battery bar	Battery charge level indicator

Widget layout is fully configurable — position, size, and scaling factor (k) can be set per-widget for each side (left and right matrix)¹.

Daemon Features

The LED Matrix Daemon provides²:

• Background daemon service with systemd integration
• Unix socket and TCP listeners for receiving images
• Dual-port support (left and right LED matrix) with automatic even/odd distribution
• Persistent serial port connection with configurable timeout and retry on failure
• Base64-encoded and multipart form data endpoints
• Port swap configuration for correct left/right mapping

Architecture

The system uses a two-process architecture: the monitoring service collects metrics at a configurable interval (default 170ms), renders them into a 9x34 pixel grayscale PNG, and transmits the image to the daemon via Unix socket. The daemon then sends the image data over serial to the LED Matrix module(s)¹².

System Metrics → led_matrix_monitoring → PNG image → Unix socket → led_matrix_daemon → Serial (ttyACM) → LED Matrix

Installation

Arch Linux (AUR)

Both packages are available in the AUR, maintained by the author¹³:

yay -S led_matrix_daemon
yay -S led_matrix_monitoring

Enable the services:

sudo systemctl enable --now led_matrix_daemon.socket led_matrix_daemon.service
sudo systemctl enable --now led_matrix_monitoring.service

Daemon configuration is located at /etc/led_matrix/daemon.toml².

NixOS

Both projects provide NixOS flakes with dedicated modules¹²:

{
  inputs.led-matrix-daemon.url = "github:night-crawler/led_matrix_daemon";
  inputs.led-matrix-monitoring.url = "github:night-crawler/led_matrix_monitoring";

  outputs = { self, nixpkgs, led-matrix-daemon, led-matrix-monitoring, ... }: {
    nixosConfigurations.your-hostname = nixpkgs.lib.nixosSystem {
      modules = [
        led-matrix-daemon.nixosModules.default
        led-matrix-monitoring.nixosModules.default
        {
          services.led-matrix-daemon.enable = true;
          services.led-matrix-monitoring = {
            enable = true;
            settings = {
              collector.max_history_samples = 20;
              collector.sample_interval = "200ms";
            };
          };
        }
      ];
    };
  };
}

The socket path is automatically configured when both NixOS modules are enabled¹.

From Source

git clone https://github.com/night-crawler/led_matrix_daemon.git
cd led_matrix_daemon && cargo build --release

git clone https://github.com/night-crawler/led_matrix_monitoring.git
cd led_matrix_monitoring && cargo build --release

Configuration

The monitoring service uses a TOML configuration file. Key settings include¹:

Setting	Description	Default
socket	Path to daemon Unix socket	/run/led-matrix/led-matrix.sock
collector.max_history_samples	Number of samples for time-series plots	10
collector.sample_interval	Metric collection interval	170ms
collector.disk_names	Disk devices to monitor (filter by name)	nvme0n1
collector.network_interfaces	Network interfaces to monitor	wlp1s0
collector.temperatures	Temperature sensors (filter by prefix)	k10temp
render.max_brightness	Maximum LED brightness (0–255)	255

Widget positions are defined per-matrix side (left/right) with configurable mid_point, max_height, start_x, start_y, end_x, end_y, and scaling factor k¹.

The daemon configuration specifies serial port paths, baud rate (115200), timeouts, and listen addresses²:

listen_address = "127.0.0.1:45935"
unix_socket = "/tmp/led-matrix.sock"
max_queue_size = 10
num_http_workers = 4

[left_port]
path = "/dev/ttyACM0"
baud_rate = 115200
timeout = "2s"
keep_open = true

Technical Details

Monitoring Service

Detail	Value
Language	Rust (2021 edition)
License	MIT
Latest version	0.3.1 (January 2025)
Total tags	5
Contributors	1 (night-crawler)
Key dependencies	sysinfo, procfs, image, imageproc, battery
Config format	TOML
Image output	9x34 grayscale PNG

Daemon

Detail	Value
Language	Rust (2021 edition)
License	MIT
Latest version	0.2.2 (January 2025)
Total tags	4
Contributors	1 (night-crawler)
Key dependencies	actix-web, serialport, tokio, kanal
Endpoints	Multipart form, Base64-encoded

Related Projects

Project	Description
inputmodule-rs	Official Framework input module tools and LED Matrix control library4
fw16-ledvu	Audio visualizer for FW16 LED Matrix (PipeWire + CAVA)
framework16-led-matrix-manager	C++/Qt GUI for controlling FW16 LED Matrix
led-matrix-controllers	Cross-firmware controllers for FW16 LED Matrix
framework-led-matrix-daemon	Go-based alternative daemon for system stats on LED Matrix
led-matrix	Python-based system monitor for FW16 LED Matrix

Footnotes

1. night-crawler/led_matrix_monitoring — GitHub ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰

2. night-crawler/led_matrix_daemon — GitHub ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶

3. AUR package: led_matrix_monitoring — Arch Linux User Repository ↩

4. FrameworkComputer/inputmodule-rs — GitHub ↩