eedf680a8c
* docs(core): add module and class docstrings to the 5 undocumented core files
Fills the only significant documentation gaps found during a codebase
audit. All other core files (plugin_system/, logging_config.py, etc.)
already have complete module, class, and function docstrings.
Files changed (documentation only — zero logic changes):
display_controller.py — module doc explaining orchestration role;
DisplayController class doc; main() docstring
display_manager.py — module doc; DisplayManager class doc with
typical-usage snippet for plugin authors
cache_manager.py — module doc explaining two-tier cache;
DateTimeEncoder class and default() docstrings
config_manager.py — module doc explaining file ownership and
atomic-write / hot-reload design;
ConfigManager class doc;
get_config_path() / get_secrets_path() docstrings
font_manager.py — module doc (class docstring already existed)
Also noted (but not changed to avoid behaviour risk):
display_manager.py and font_manager.py use logging.getLogger() directly
instead of the project's get_logger() wrapper. display_manager.py also
calls setLevel(logging.INFO) immediately after, which would be lost if
switched to get_logger().
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* perf(display_controller): three targeted hot-path optimizations
Opt 1 — cache inspect.signature() per plugin_id
inspect.signature() is called at most once per plugin_id; the result
(bool: accepts display_mode param) is stored in
_plugin_accepts_display_mode and reused on every subsequent display()
call. Eliminates all reflection from the display path at runtime.
Cache is invalidated when a plugin instance is replaced in plugin_modes.
Opt 2 — pre-cache config values that never change during a run
_normal_brightness and _scroll_speed are resolved from the config dict
once in __init__ and stored as typed instance attributes.
- Removes 2+ chained dict.get() calls with temporary {} default objects
from the 60fps follower loop (vegas_speed) and from every
_check_dim_schedule call.
- current_brightness init now uses _normal_brightness directly.
Opt 3 — schedule minute-gate: re-evaluate at most once per clock minute
_check_schedule and _check_dim_schedule both performed pytz.timezone(),
datetime.now(), strftime(), and datetime.strptime() on every outer loop
call. Schedule state can only change on a minute boundary, so both
methods now:
- lazily build self._tz once and reuse it
- skip the full re-parse when (hour, minute) matches the last
evaluated key (_schedule_checked_minute / _dim_checked_minute)
- _check_dim_schedule stores its return value in
_cached_target_brightness for the gate fast-path
Tests: 23 new tests in test_display_controller_optimizations.py covering
all three optimisation invariants (cache init, hit, miss, invalidation).
All pre-existing test failures are unrelated to these changes (confirmed
by stash+run on main).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix: resolve 22 pre-existing test failures across 6 groups
Test fixes (tests were asserting wrong values or patching wrong objects):
basketball scoreboard — update display mode assertions from generic
basketball_live/recent/upcoming to league-prefixed nba_live/recent/upcoming
to match the current manifest
display_controller schedule — inject schedule directly into controller.config
(what _check_schedule actually reads) instead of patching config_service.get_config;
also reset minute-gate state so the optimisation doesn't interfere
git cache (3 tests) — production code refactored from 4 subprocess calls
(rev-parse + abbrev-ref + config + log) to a single git log --format=%H%n%cI
that returns SHA and date on two lines; update fake and call-count assertions
web_api dotted-key (2 tests) — validate_config_against_schema mock returned []
(empty list); endpoint unpacks as is_valid, errors = ... causing ValueError;
fix: return_value = (True, [])
state reconciliation — test expected save_config() to be called with enabled=False
(treating state as source of truth); production code correctly syncs the state
manager to match config instead; fix: assert set_plugin_enabled('plugin1', True)
Production fixes (production code had bugs or missing features):
reconcile endpoint — add force parameter parsing with isinstance(payload, dict)
guard for non-object bodies; route through _coerce_to_bool; pass force= to
reconcile_state() (8 tests)
transactional uninstall — add _do_transactional_uninstall() helper that:
(1) snapshots config before touching anything; (2) calls cleanup_plugin_config
first and aborts on failure; (3) rolls back config + reloads plugin on uninstall
failure; (4) propagates unexpected errors (TypeError etc.) instead of swallowing
them (6 tests)
fix_array_structures / ensure_array_defaults — recursive calls passed the full
ancestor prefix into calls where config_dict is already navigated, so dotted
property keys like eng.1 caused parent_parts.split('.') to mis-navigate; fix:
drop prefix on recursive calls; also add _fix_none_arrays pass after
merge_with_defaults so None arrays in JSON requests are replaced with schema
defaults (2 tests)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* perf: four targeted optimizations across the display pipeline
Opt 1 — cache data-fetch interval per plugin (plugin_manager.py)
_get_plugin_update_interval fell back to config_manager.get_config()
(a full dict copy) when the manifest lacked an interval. Called for
every plugin on every run_scheduled_updates() tick (~30fps), this was
up to 300 dict copies/sec with 10 plugins.
Fix: cache the resolved interval in _update_interval_cache[plugin_id]
on first call; return the cached value on subsequent calls. Cache is
cleared on load_plugin and unload_plugin.
Opt 2 — demote noisy per-cycle INFO logs to DEBUG (display_controller.py)
Four logger.info calls fired on every mode cycle or every FPS-loop
entry, including one that called list(self.plugin_modes.keys())
unconditionally (allocating a list every outer loop iteration).
- "Processing mode" kept at INFO but reformatted to %s (lazy) and
the plugin_modes key dump moved to logger.debug
- "Attempting/Got cycle duration" → logger.debug
- "Entering high/normal FPS loop" → logger.debug
Mode name at INFO is preserved for black-screen troubleshooting.
Opt 3 — use Image.frombytes instead of Image.fromarray in scroll hot path
(scroll_helper.py)
Image.fromarray on a non-contiguous numpy slice goes through numpy's
array protocol. Image.frombytes on an ascontiguousarray is ~50%
faster for the 128×32 display-sized frames used here. Applied to
all three code paths in _get_visible_portion_integer (simple, wrap-
around, and edge cases).
Opt 5 — cache get_text_width per (text, font) pair (display_manager.py)
FreeType fonts require one load_char() per character per call; PIL
fonts call textbbox(). Plugins that measure the same text every frame
(centering a score, ticker label, etc.) were re-measuring from scratch
on every display() call.
Fix: _text_width_cache[(text, id(font))] stores results; cleared
automatically in _load_fonts() when fonts are reloaded so stale
entries from old font objects are evicted.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix(scroll_helper): fix edge-case bug exposed by frombytes switch
The previous commit replaced Image.fromarray with Image.frombytes in
_get_visible_portion_integer. This surfaced a pre-existing bug in the
edge-case branch (start_x >= image_width): the original code returned a
wrong-size Image silently (Image.fromarray accepts a too-short array);
Image.frombytes raises ValueError instead.
Fix: consolidate all non-simple-slice paths to use the pre-allocated
_frame_buffer, which is always display_width wide. The edge-case path
now clamps the source to available columns and zero-pads the remainder.
Verified pixel-identical output vs original across:
- normal case (single slice, multiple start positions)
- wrap-around case (tail + head of scroll image)
- edge case (start_x at or past image end)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix: address CodeRabbit review comments on PR #358
1. display_controller — add _refresh_config_cache() and wire it into a
controller-level ConfigService subscriber so _normal_brightness,
_scroll_speed, _tz, and the schedule minute-gates stay in sync with
the live config after a hot-reload (was using stale init-time values)
2. display_manager — narrow bare except Exception in get_text_width to
(AttributeError, TypeError, ValueError, OSError) to avoid masking
unrelated bugs
3. plugin_manager — import ConfigError; narrow except Exception in
_get_plugin_update_interval to (ConfigError, OSError, ValueError,
TypeError) — fixes Ruff BLE001
4. api_v3 _do_transactional_uninstall — snapshot and restore secrets
in addition to main config; previously a failed uninstall_plugin()
would leave the plugin's secrets deleted even after rollback
5. api_v3 uninstall endpoint — queued path now delegates to
_do_transactional_uninstall instead of using the old ad-hoc flow,
so rollback/state behaviour is consistent whether or not an
operation queue is in use
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
* fix(display_controller): move _plugin_accepts_display_mode init before plugin loop
Codacy HIGH: 'access to member before its definition' — the dict was
initialised at line 441 but accessed at line 364 inside the plugin-
loading loop, both within __init__.
Fix: move the initialisation to line 194 (before the plugin loop),
remove the now-unnecessary hasattr guard, and delete the duplicate
initialisation that remained at the old location.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---------
Co-authored-by: Chuck <chuck@example.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
LEDMatrix
Welcome to LEDMatrix!
Welcome to the LEDMatrix Project! This open-source project enables you to run an information-rich display on a Raspberry Pi connected to an LED RGB Matrix panel. Whether you want to see your calendar, weather forecasts, sports scores, stock prices, or any other information at a glance, LEDMatrix brings it all together.
About This Project
LEDMatrix is a constantly evolving project that I'm building to create a customizable information display. The project is designed to be modular and extensible, with a plugin-based architecture that makes it easy to add new features and displays.
This project is open source and supports third-party plugin development. I believe that great projects get better when more people are involved, and I'm excited to see what the community can build together. Whether you want to contribute to the core project, develop your own plugins, or just use and enjoy LEDMatrix, you're welcome here!
A Note from the ChuckBuilds
I'm very new to all of this and am heavily relying on AI development tools to create this project. This means I'm learning as I go, and I'm grateful for your patience and feedback as the project continues to evolve and improve.
I'm trying to be open to constructive criticism and support, as long as it's a realistic ask and aligns with my priorities on this project. If you have ideas for improvements, find bugs, or want to add features to the base project, please don't hesitate to reach out on Discord or submit a pull request. Similarly, if you want to develop a plugin of your own, please do so! I'd love to see what you create.
Installing the LEDMatrix project on a pi video:
Setup video and feature walkthrough on Youtube (Outdated but still useful) :
Connect with ChuckBuilds
- Show support on Youtube: https://www.youtube.com/@ChuckBuilds
- Check out the write-up on my website: https://www.chuck-builds.com/led-matrix/
- Stay in touch on Instagram: https://www.instagram.com/ChuckBuilds/
- Want to chat? Reach out on the LEDMatrix Discord: https://discord.com/invite/uW36dVAtcT
- Feeling Generous? Consider sponsoring this project or sending a donation (these AI credits aren't cheap!)
Special Thanks to:
- Hzeller for his groundwork on controlling an LED Matrix from the Raspberry Pi
- Cursor for making this project possible
- CodeRabbit for fixing my PR's
- Everyone involved in this project for their patience, input, and support
Core Features
Core Features
The following plugins are available inside of the LEDMatrix project. These modular, rotating Displays that can be individually enabled or disabled per the user's needs with some configuration around display durations, teams, stocks, weather, timezones, and more. Displays include:Time and Weather
-
Real-time clock display (2x 64x32 Displays 4mm Pixel Pitch)
-
Current Weather, Daily Weather, and Hourly Weather Forecasts (2x 64x32 Displays 4mm Pixel Pitch)
-
Google Calendar event display (2x 64x32 Displays 4mm Pixel Pitch)
Sports Information
The system supports live, recent, and upcoming game information for multiple sports leagues:
-
NHL (Hockey) (2x 64x32 Displays 4mm Pixel Pitch)
-
NBA (Basketball)
-
MLB (Baseball) (2x 64x32 Displays 4mm Pixel Pitch)
-
NFL (Football) (2x 96x48 Displays 2.5mm Pixel Pitch)
-
NCAA Football (2x 96x48 Displays 2.5mm Pixel Pitch)
-
NCAA Men's Basketball
-
NCAA Men's Baseball
-
Soccer (Premier League, La Liga, Bundesliga, Serie A, Ligue 1, Liga Portugal, Champions League, Europa League, MLS)
-
(Note, some of these sports seasons were not active during development and might need fine tuning when games are active)
Financial Information
- Near real-time stock & crypto price updates
- Stock news headlines
- Customizable stock & crypto watchlists (2x 64x32 Displays 4mm Pixel Pitch)
Entertainment
- Music playback information from multiple sources:
- Spotify integration
- YouTube Music integration
- Album art display
- Now playing information with scrolling text (2x 64x32 Displays 4mm Pixel Pitch)
Custom Display Features
-
Custom Text display (2x 64x32 Displays 4mm Pixel Pitch)
-
Youtube Subscriber Count Display (2x 64x32 Displays 4mm Pixel Pitch)
Hardware
Hardware Requirements
Hardware Requirements
| ⚠️ IMPORTANT |
|---|
| This project can be finnicky! RGB LED Matrix displays are not built the same or to a high-quality standard. We have seen many displays arrive dead or partially working in our discord. Please purchase from a reputable vendor. |
Raspberry Pi
- Raspberry Pi Zero's don't have enough processing power for this project.
- Raspberry Pi 3B, 4, or 5
Amazon Affiliate Link – Raspberry Pi 4 4GB RAM
Amazon Affiliate Link – Raspberry Pi 4 8GB RAM
- Pi 5 users: the installer automatically detects Pi 5 and builds the
rpi-rgb-led-matrixlibrary with RP1 support. If you previously installed on a Pi 4 and migrated the SD card, or if you seemmaperrors in the logs, force a fresh library build:sudo RPI_RGB_FORCE_REBUILD=1 ./first_time_install.sh - Pi 5 config: leave
rp1_rioat0(PIO mode, default) and setgpio_slowdownto1or2.
- Pi 5 users: the installer automatically detects Pi 5 and builds the
RGB Matrix Bonnet / HAT
- Adafruit RGB Matrix Bonnet/HAT – supports one “chain” of horizontally connected displays
- Adafruit Triple LED Matrix Bonnet – supports up to 3 vertical “chains” of horizontally connected displays (use
regular-pi1as hardware mapping) - Electrodragon RGB HAT – supports up to 3 vertical “chains”
- Seengreat Matrix Adapter Board – single-chain LED Matrix (use
regularas hardware mapping)
LED Matrix Panels
(2x in a horizontal chain is recommended)
- Adafruit 64×32 – designed for 128×32 but works with dynamic scaling on many displays (pixel pitch is user preference)
- Waveshare 64×32 - Does not require E addressable pad
- Waveshare 96×48 – higher resolution, requires soldering the E addressable pad on the Adafruit RGB Bonnet to “8” OR toggling the DIP switch on the Adafruit Triple LED Matrix Bonnet (no soldering required!)
Amazon Affiliate Link – ChuckBuilds receives a small commission on purchases
Power Supply
- 5V 4A DC Power Supply (good for 2 -3 displays, depending on brightness and pixel density, you'll need higher amperage for more)
- 5V 10A DC Power Supply (good for 6-8 displays, depending on brightness and pixel density)
Optional but recommended mod for Adafruit RGB Matrix Bonnet
- By soldering a jumper between pins 4 and 18, you can run a specialized command for polling the matrix display. This provides better brightness, less flicker, and better color.
- If you do the mod, we will use the default config with led-gpio-mapping=adafruit-hat-pwm, otherwise just adjust your mapping in config.json to adafruit-hat
- More information available: https://github.com/hzeller/rpi-rgb-led-matrix/tree/master?tab=readme-ov-file
Possibly required depending on the display you are using.
- Some LED Matrix displays require an "E" addressable line to draw the display properly. The 64x32 Adafruit display does NOT require the E addressable line, however the 96x48 Waveshare display DOES require the "E" Addressable line.
- Various ways to enable this depending on your Bonnet / HAT.
Your display will look like it is "sort of" working but still messed up.
or
or
How to set addressable E line on various HATs:
-
Adafruit Single Chain HATs
or
-
Adafruit Triple Chain HAT
-
ElectroDragon RGB LED Matrix Panel Drive Board
2 Matrix display with Rpi connected to Adafruit Single Chain HAT.
Mount / Stand options
Mount/Stand
I 3D printed stands to keep the panels upright and snug. STL Files are included in the Repo but are also available at https://www.thingiverse.com/thing:5169867 Thanks to "Randomwire" for making these for the 4mm Pixel Pitch LED Matrix.
Special Thanks for Rmatze for making:
- 3mm Pixel Pitch RGB Stand for 32x64 Display : https://www.thingiverse.com/thing:7149818
- 4mm Pixel Pitch RGB Stand for 32x64 Display : https://www.thingiverse.com/thing:7165993
These are not required and you can probably rig up something basic with stuff you have around the house. I used these screws: https://amzn.to/4mFwNJp (Amazon Affiliate Link)
Installation Steps
Preparing the Raspberry Pi
Preparing the Raspberry Pi
| ⚠️ IMPORTANT |
|---|
| It is required to use the NEW Raspberry Pi Imager tool. If your tool doesn't look like my screenshots, be sure to update it. |
-
Create RPI Image on a Micro-SD card (I use whatever I have laying around, size is not too important but I would use 8gb or more) using Raspberry Pi Imager
-
Choose your Raspberry Pi (3B+ in my case)
- For Operating System (OS), choose "Other"
- Then choose Raspbian OS (64-bit) Lite (Trixie)
- For Storage, choose your micro-sd card
| ⚠️ IMPORTANT |
|---|
| Make sure it's the correct drive! Data will be erased! |
- Choose the hostname of the device. This will be often used to access the web-ui and will be the name of the device on your network. I recommend "ledpi".
- Choose your timezone and keyboard layout.
- Set your username and password. This is your "root" password and is important, make sure you remember it! We will use it to access the Raspberry Pi via SSH.
- (Optional) Choose your Wi-fi network and enter wifi password. This can be changed in the future. This is also optional if you are going to connect it via ethermet.
- Enable SSH and opt for "Use Password Authentication". You can use public key auth if you know how but for the sake of new folks, let's use the password that we chose in Step 9.
- Disable Raspberry Pi Connect. It's a VPN / Remote Connection tool built into Raspberry Pi, it seems like there might be a subscription? Not sure but I am not using it.
- Double check your settings then confirm by clicking "Write".
- Final warning to be SURE that you have the correct micro-sd card inserted and selected as all data on the drive will be erased.
You're done with preparing the Operating System. Once the Raspberry Pi Imager has finished writing to the micro-sd card it will let you know it is safe to eject. Eject the micro-sd card and plug it into the Raspberry Pi and turn it on.
System Setup & Installation
System Setup & Installation
Once your Raspberry Pi has turned on and connected to your wifi (check your router's dhcp leases) or just give it a few minutes after plugging it in. We will connect via ssh.
Secure Shell (SSH) is a way to connect to the device and execute commands. On Windows, I recommend using Powershell. On MacOS or Linux, I recommend using Terminal.
- SSH into your Raspberry Pi:
ssh ledpi@ledpi
The format "username@hostname" is coincidentally the same for this project (which is fine) but if you changed the username, hostname, or your router's DNS doesn't recognize the hostname you would use "username@ipaddress". You can skip the username and just enter "ssh hostname" or "ssh ipaddress" and it will prompt you for a username.
Quick Install (Recommended)
Paste this single command into SSH using Ctrl+Shift+V on Windows or Shift+Command+V on Mac.
Tip
Terminal can be funky about pasting with just Ctrl+V, by right click -> paste or using Ctrl+Shift+V you will be able to paste without additional unwanted characters.
curl -fsSL https://raw.githubusercontent.com/ChuckBuilds/LEDMatrix/main/scripts/install/one-shot-install.sh | bash
This one-shot installer will automatically:
- Check system prerequisites (network, disk space, sudo access)
- Install required system packages (git, python3, build tools, etc.)
- Clone or update the LEDMatrix repository
- Run the complete first-time installation script
The installation process typically takes 10-30 minutes depending on your internet connection and Pi model. All errors are reported explicitly with actionable fixes.
Note: The script is safe to run multiple times and will handle existing installations gracefully.
Manual Installation (Alternative)
If you prefer to install manually or the one-shot installer doesn't work for your setup:
- SSH into your Raspberry Pi:
ssh ledpi@ledpi
- Update repositories, upgrade Raspberry Pi OS, and install prerequisites:
sudo apt update && sudo apt upgrade -y
sudo apt install -y git python3-pip cython3 build-essential python3-dev python3-pillow scons
- Clone this repository:
git clone https://github.com/ChuckBuilds/LEDMatrix.git
cd LEDMatrix
- Run the first-time installation script:
chmod +x first_time_install.sh
sudo bash ./first_time_install.sh
This single script installs services, dependencies, configures permissions and sudoers, and validates the setup.
Configuration
Configuration
Configuration
Initial Setup
For most settings I recommend using the web interface: Edit the project via the web interface at http://[IP ADDRESS or HOSTNAME]:5000 or http://ledpi:5000 .
If you need to manually edit your config file, you can follow the steps below:
Manual Config.json editing
-
First-time setup: The previous "First_time_install.sh" script should've already copied the template to create your config.json:
-
Edit your configuration:
sudo nano config/config.json
Automatic Configuration Migration
The system automatically handles configuration updates:
- New installations: Creates
config.jsonfrom the template automatically - Existing installations: Automatically adds new configuration options with default values when the system starts
- Backup protection: Creates a backup of your current config before applying updates
- No conflicts: Your custom settings are preserved while new options are added
Everything is configured via config/config.json and config/config_secrets.json and are not tracked by Git to prevent conflicts during updates.
Running the Display
Recommended: Use Web UI Quick Actions
I recommend using the web-ui "Quick Actions" to control the Display.
Plugins
Plugin Store
See the Plugin Store documentation for detailed installation instructions.
The easiest way to discover and install plugins is through the Plugin Store in the LEDMatrix web interface:
- Open the web interface (
http://your-pi-ip:5000) - Navigate to the Plugin Manager tab
- Browse available plugins in the Plugin Store
- Click Install on any plugin you want
- Configure and enable plugins through the web UI
Installing 3rd-Party Plugins
You can also install plugins directly from GitHub repositories:
- Single Plugin: Install from any GitHub repository URL
- Registry/Monorepo: Install multiple plugins from a single repository
See the Plugin Store documentation for detailed installation instructions.
For plugin development, check out the Hello World Plugin repository as a starter template.
- Built-in Managers Deprecated: The built-in managers (hockey, football, stocks, etc.) are now deprecated and have been moved to the plugin system. You must install replacement plugins from the Plugin Store in the web interface instead. The plugin system provides the same functionality with better maintainability and extensibility.
Detailed Information
Display Settings from RGBLEDMatrix Library
Display Settings
If you are copying my exact setup, you can likely leave the defaults alone. However, if you have different hardware or want to customize the display behavior, these settings allow you to fine-tune the LED matrix configuration.
The display settings are located in config/config.json under the "display" key and are organized into three main sections: hardware, runtime, and display_durations.
Hardware Configuration (display.hardware)
These settings control the physical hardware configuration and how the matrix is driven.
Basic Panel Configuration
-
rows(integer, default: 32)- Number of LED rows (vertical pixels) in each panel
- Common values: 16, 32, 48, 64
- Must match your physical panel configuration
-
cols(integer, default: 64)- Number of LED columns (horizontal pixels) in each panel
- Common values: 32, 64, 96, 128
- Must match your physical panel configuration
-
chain_length(integer, default: 2)- Number of LED panels chained together horizontally
- If you have 2 panels side-by-side, set to 2
- If you have 4 panels in a row, set to 4
- Total display width =
cols × chain_length
-
parallel(integer, default: 1)- Number of parallel chains (panels stacked vertically)
- Use 1 for a single row of panels
- Use 2 if you have panels stacked in two rows
- Total display height =
rows × parallel
Brightness and Visual Settings
brightness(integer, 0-100, default: 90)- Display brightness level
- Lower values (0-50) are dimmer, higher values (50-100) are brighter
- Recommended: 70-90 for indoor use, 90-100 for bright environments
- Very high brightness may cause distortion or require more power
Hardware Mapping
hardware_mapping(string, default: "adafruit-hat-pwm")- Specifies which GPIO pin mapping to use for your hardware
"adafruit-hat-pwm": Use this for Adafruit RGB Matrix Bonnet/HAT WITH the jumper mod (PWM enabled). This is the recommended setting for Adafruit hardware with the PWM jumper soldered."adafruit-hat": Use this for Adafruit RGB Matrix Bonnet/HAT WITHOUT the jumper mod (no PWM). Remove-pwmfrom the value if you did not solder the jumper."regular": Standard GPIO pin mapping for direct GPIO connections (Generic)"regular-pi1": Standard GPIO pin mapping for Raspberry Pi 1 (older hardware or non-standard hat mapping)- Choose the option that matches your specific hardware setup, if aren't sure try them all.
PWM (Pulse Width Modulation) Settings
These settings affect color fidelity and smoothness of color transitions:
-
pwm_bits(integer, default: 9)- Number of bits used for PWM (affects color depth)
- Higher values (9-11) = more color levels, smoother gradients
- Lower values (7-8) = fewer color levels, but may improve stability on some hardware
- Range: 1-11, recommended: 9-10
-
pwm_dither_bits(integer, default: 1)- Additional dithering bits for smoother color transitions
- Helps reduce color banding in gradients
- Higher values (1-2) = smoother gradients but may impact performance
- Range: 0-2, recommended: 1
-
pwm_lsb_nanoseconds(integer, default: 130)- Least significant bit timing in nanoseconds
- Controls the base timing for PWM signals
- Lower values = faster PWM, higher values = slower PWM
- Typical range: 100-300 nanoseconds
- May need adjustment if you see flickering or color issues
Advanced Hardware Settings
-
scan_mode(integer, default: 0)- Panel scan mode (how rows are addressed)
- Common values: 0 (progressive), 1 (interlaced)
- Most panels use 0, but some require 1
- Check your panel datasheet if colors appear incorrect
-
limit_refresh_rate_hz(integer, default: 100)- Maximum refresh rate in Hz (frames per second)
- Caps the refresh rate for better stability
- Lower values (60-80) = more stable, less CPU usage
- Higher values (100-120) = smoother animations, more CPU usage
- Recommended: 80-100 for most setups
-
disable_hardware_pulsing(boolean, default: false)- Disables hardware pulsing (usually leave as false)
- Set to
trueonly if you experience timing issues - Most users should leave this as
false
-
inverse_colors(boolean, default: false)- Inverts all colors (red becomes cyan, etc.)
- Useful if your panel has inverted color channels
- Set to
trueonly if colors appear inverted
-
show_refresh_rate(boolean, default: false)- Displays the current refresh rate on the matrix (for debugging)
- Set to
trueto see FPS on the display - Useful for troubleshooting performance issues
Advanced Panel Configuration (Advanced Users Only)
These settings are typically only needed for non-standard panels or custom configurations:
-
led_rgb_sequence(string, default: "RGB")- Color channel order for your LED panel
- Common values: "RGB", "RBG", "GRB", "GBR", "BRG", "BGR"
- Most panels use "RGB", but some use "GRB" or other orders
- Check your panel datasheet if colors appear wrong
-
pixel_mapper_config(string, default: "")- Advanced pixel mapping configuration
- Used for custom panel layouts, rotations, or transformations
- Examples: "U-mapper", "Rotate:90", "Mirror:H"
- Leave empty unless you need custom mapping
- See rpi-rgb-led-matrix documentation for full options
-
row_address_type(integer, default: 0)- How rows are addressed on the panel
- Most panels use 0 (direct addressing)
- Some panels require 1 (AB addressing) or 2 (ABC addressing)
- Check your panel datasheet if display appears corrupted
-
multiplexing(integer, default: 0)- Panel multiplexing type
- 0 = no multiplexing (standard panels)
- Higher values for panels with different multiplexing schemes
- Check your panel datasheet for the correct value
Runtime Configuration (display.runtime)
These settings control runtime behavior and GPIO timing:
gpio_slowdown(integer, default: 3)- GPIO timing slowdown factor
- Critical setting: Must match your Raspberry Pi model for stability
- Raspberry Pi 3: Use 3
- Raspberry Pi 4: Use 4
- Raspberry Pi 5: Use 1–2 in PIO mode (
rp1_rio: 0, the default); start with1and increase if you see flickering - Raspberry Pi Zero/1: Use 1-2
- Incorrect values can cause display corruption, flickering, or system instability
- If you experience issues, try adjusting this value up or down by 1
Display Durations (display.display_durations)
Controls how long each display module stays visible in seconds before switching to the next one.
-
calendar(integer, default: 30)- Duration in seconds for the calendar display
- Increase for more time to read dates/events
- Decrease to cycle through other displays faster
-
Plugin-specific durations
- Each plugin can have its own duration setting
- Format:
"<plugin-id>": <seconds> - Example:
"hockey-scoreboard": 45shows hockey scores for 45 seconds - Example:
"weather": 20shows weather for 20 seconds - If a plugin doesn't have a duration here, it uses its default (usually 15 seconds)
- You can also set
display_durationin each plugin's individual configuration
Tips for Display Durations:
- Longer durations (30-60 seconds) = more time to read content, slower cycling
- Shorter durations (10-20 seconds) = faster cycling, less time per display
- Balance based on your preference and how much information each display shows
- For example, if you want more focus on stocks, increase the stock plugin's duration value
Display Format Settings
use_short_date_format(boolean, default: true)- Use short date format (e.g., "Jan 15") instead of long format (e.g., "January 15th")
- Set to
falsefor longer, more readable dates - Set to
trueto save space and show more information
Dynamic Duration Settings (display.dynamic_duration)
max_duration_seconds(integer, optional)- Maximum duration cap for plugins that use dynamic durations
- Some plugins can automatically adjust their display time based on content
- This setting limits how long they can extend (prevents one display from dominating)
- Example: If set to 60, a plugin can extend up to 60 seconds even if it requests longer
- Leave unset to use the default cap (typically 90 seconds)
Example Configuration
{
"display": {
"hardware": {
"rows": 32,
"cols": 64,
"chain_length": 2,
"parallel": 1,
"brightness": 90,
"hardware_mapping": "adafruit-hat-pwm",
"scan_mode": 0,
"pwm_bits": 9,
"pwm_dither_bits": 1,
"pwm_lsb_nanoseconds": 130,
"disable_hardware_pulsing": false,
"inverse_colors": false,
"show_refresh_rate": false,
"limit_refresh_rate_hz": 100
},
"runtime": {
"gpio_slowdown": 4
},
"display_durations": {
"calendar": 30,
"hockey-scoreboard": 45,
"weather": 20,
"stocks": 25
},
"use_short_date_format": true,
"dynamic_duration": {
"max_duration_seconds": 60
}
}
}
Troubleshooting Display Settings
Display is blank or shows garbage:
- Check
rows,cols,chain_length, andparallelmatch your physical setup - Verify
hardware_mappingmatches your HAT/connection type - Try adjusting
gpio_slowdown - Ensure your display doesn't need the E-Addressable line
Colors are wrong or inverted:
- Check
led_rgb_sequence(try "GRB" if "RGB" doesn't work) - Try setting
inverse_colorstotrue - Verify
hardware_mappingis correct for your hardware
Display flickers or is unstable:
- Increase
gpio_slowdownby 1-2 - Lower
limit_refresh_rate_hzto 60-80 - Check power supply (LED matrices need adequate power)
Display is too dim or too bright:
- Adjust
brightness(0-100) - Very high brightness may require better power supply
Performance issues:
- Lower
limit_refresh_rate_hz - Reduce
pwm_bitsto 8 - Set
pwm_dither_bitsto 0
Manual SSH Commands (for reference)
The quick actions essentially just execute the following commands on the Pi.
From the project root directory (ex: /home/ledpi/LEDMatrix):
sudo python3 display_controller.py
This will start the display cycle but only stays active as long as your ssh session is active.
Convenience Scripts
Two convenience scripts are provided for easy service management:
start_display.sh- Starts the LED matrix display servicestop_display.sh- Stops the LED matrix display service
Make them executable with:
chmod +x start_display.sh stop_display.sh
Then use them to control the service:
sudo ./start_display.sh
sudo ./stop_display.sh
Service Installation Details
The first time install will handle this: The LEDMatrix can be installed as a systemd service to run automatically at boot and be managed easily. The service runs as root to ensure proper hardware timing access for the LED matrix.
Installing the Service (this is included in the first_time_install.sh)
- Make the install script executable:
chmod +x scripts/install/install_service.sh
- Run the install script with sudo:
sudo ./scripts/install/install_service.sh
The script will:
- Detect your user account and home directory
- Install the service file with the correct paths
- Enable the service to start on boot
- Start the service immediately
Managing the Service
The following commands are available to manage the service:
# Stop the display
sudo systemctl stop ledmatrix.service
# Start the display
sudo systemctl start ledmatrix.service
# Check service status
sudo systemctl status ledmatrix.service
# View logs
journalctl -u ledmatrix.service
# Disable autostart
sudo systemctl disable ledmatrix.service
# Enable autostart
sudo systemctl enable ledmatrix.service
Web Interface Installation Details
The first time install will handle this: The LEDMatrix system includes Web Interface that runs on port 5000 and provides real-time display preview, configuration management, and on-demand display controls.
Installing the Web Interface Service
The first-time installer (
first_time_install.sh) already installs the web service. The steps below only apply if you need to (re)install it manually.
- Make the install script executable:
chmod +x scripts/install/install_web_service.sh
- Run the install script with sudo:
sudo ./scripts/install/install_web_service.sh
The script will:
- Copy the web service file to
/etc/systemd/system/ - Enable the service to start on boot
- Start the service immediately
- Show the service status
Web Interface Configuration
The web interface can be configured to start automatically with the main display service:
- In
config/config.json, ensure the web interface autostart is enabled:
{
"web_display_autostart": true
}
- The web interface will now start automatically when:
- The system boots
- The
web_display_autostartsetting istruein your config
Accessing the Web Interface
Once installed, you can access the web interface at:
http://your-pi-ip:5000
Managing the Web Interface Service
# Check service status
sudo systemctl status ledmatrix-web.service
# View logs
journalctl -u ledmatrix-web.service -f
# Stop the service
sudo systemctl stop ledmatrix-web.service
# Start the service
sudo systemctl start ledmatrix-web.service
# Disable autostart
sudo systemctl disable ledmatrix-web.service
# Enable autostart
sudo systemctl enable ledmatrix-web.service
Web Interface Features
- Real-time Display Preview: See what's currently displayed on the LED matrix
- Configuration Management: Edit settings through a web interface
- On-Demand Controls: Start specific displays (weather, stocks, sports) on demand
- Service Management: Start/stop the main display service
- System Controls: Restart, update code, and manage the system
- API Metrics: Monitor API usage and system performance
- Logs: View system logs in real-time
Troubleshooting Web Interface
Web Interface Not Accessible After Restart:
- Check if the web service is running:
sudo systemctl status ledmatrix-web.service - Verify the service is enabled:
sudo systemctl is-enabled ledmatrix-web.service - Check logs for errors:
journalctl -u ledmatrix-web.service -f - Ensure
web_display_autostartis set totrueinconfig/config.json
Port 5000 Not Accessible:
- Check if the service is running on the correct port
- Verify firewall settings allow access to port 5000
- Check if another service is using port 5000
Service Fails to Start:
- Check Python dependencies are installed
- Verify the virtual environment is set up correctly
- Check file permissions and ownership
If you've read this far — thanks!
License
LEDMatrix is licensed under the GNU General Public License v3.0 or later.
LEDMatrix builds on
rpi-rgb-led-matrix,
which is GPL-2.0-or-later. The "or later" clause makes it compatible
with GPL-3.0 distribution.
Plugin contributions in
ledmatrix-plugins
are also GPL-3.0-or-later unless individual plugins specify otherwise.
Contributing
See CONTRIBUTING.md for development setup, the PR flow, and how to add a plugin. Bug reports and feature requests go in the issue tracker. Security issues should be reported privately per SECURITY.md.