PIXELIX

Full RGB LED matrix, based on an ESP32 and WS2812B LEDs.

• Motivation
• Introduction
• Features
• Original Setup
• Attention
• Supported Development Boards
  • Recommendation
  • Special Variants
• Installation
• Very First Startup
  • Variant 1: Configure wifi station SSID and passphrase with the browser
  • Variant 2: Configure wifi station SSID and passphrase with the terminal
  • PIXELIX Is Ready
• User Interface
• Details
• FAQ
  • Where to change panel topology of the LED matrix?
  • How to change text properties?
  • The display only shows a error code, like "E4". What does that mean?
  • How can I use animated icons?
  • How do I know that my sensor is recognized?
  • Why do I see sometimes values from the LDR in the SensorPlugin, although no LDR is installed?
  • How can I use alternative icons?
  • Is it possible to use a font with 8px height?
  • How to configure the date/time format?
  • How to configure my own list of plugins?
• Used Libraries
• Issues, Ideas And Bugs
• License
• Contribution

Motivation

My initial goal was to have a remote display that would show multiple kind of information and run reliably 24/7. Can be connected to the local network via WiFi and controlled via REST API or Websocket. PIXELIX was born! :-)

Introduction

The PIXELIX firmware is for ESP32 boards that controls a RGB LED matrix. It can be used to display text and animations.

Features

• Supports 32x8 LED matrix size out of the box. Its possible to cascade another matrix to have a longer display.
• Can display static or scrolling text, as well as static or animated icons.
• Includes a web interface for configuring and controlling the LED matrix.
• Supports REST API and MQTT for remote control and integration with other systems, like Home Assistant.
• Can be extended with custom effects and animations. See list of plugins.

Please note, that not every feature might be available for all kind of development boards. E.g. for MQTT support you need 8 a development board with 8 MB flash or more. See the config<variant>.ini configuration files in ./config folder.

Some impressions
	...

Original Setup

The original setup for development and the first release was:

• ESP32 DevKitV1
• WS2812B 5050 8x32 RGB Flexible LED Matrix Panel
• Power supply 5 V / 4 A

The following shows the absolute minimal wiring setup e.g. for the ESP32 DevKitV1. It may differ depended on your development board.

Attention

⚠️ If you power the development board and the LED matrix via USB: Be very careful, because it may destroy your ESP32 board if the LED current is too high. Avoid increasing the LED display brightness or filling it complete with white pixels. Please use a external power supply with at least 5V / 4A.

ℹ️ To avoid any damage on your hardware and by the way to your eyes ;-), PIXELIX starts up with a low brightness setting. Additional the max. current is limited by software.

Supported Development Boards

In the meantime several other boards are supported as well. You can find them in the list of boards.

Recommendation

Its recommended to use a development board with 8 MB flash or more. 4 MB flash modules are still supported, but the functionality is limited. Also recommended is to use a esp32 dual core variant, which provides more processing power.

Special Variants

Additional supported variants, which were original not in focus:

• LILYGO® TTGO T-Display ESP32 WiFi and Bluetooth Module Development Board For Arduino 1.14 Inch LCD
• LILYGO® T-Display ESP32-S3 1.9 inch ST7789 LCD Display Touch Screen Development Board

Although PIXELIX was designed to show information, that is pushed or pulled via REST API, the following sensors can be directly connected and evaluated:

• Temperature and humidity sensors DHTx
• Temperature and humidity sensors SHT3x
• Digitial microphone INMP441 for some sound reactive stuff.

Installation

The following steps are necessary for the first time and to get PIXELIX initial running on the target. Once it runs, later on the firmware and filesystem can be updated via the PIXELIX web interface.

1. Setup the toolchain.
2. Build the software and check whether the toolchain works.
3. Upload/Update the software and firmware to the target.
4. Verify that the LED panel topology is correct and you see the "Hello World" on the display.

Note, that the LED panel topology and the display width/height can currently not be changed in the web interface. If its necessary, adapt first in ./lib/HalLedMatrix/Board.h the width and height according your LED matrix. In the ./lib/HalLedMatrix/LedMatrix.h file you have to change the member variable m_topo according to your physical panel topology. Take a look how your pixels are wired on the pcb and use the following page to choose the right one: https://github.com/Makuna/NeoPixelBus/wiki/Layout-objects

Very First Startup

If the device starts the very first time, the wifi station SSID and passphrase settings are empty. They can be configured in two possible ways:

1. Using the browser and set them in the captive portal.
2. Using a terminal connecting via usb.

Variant 1: Configure wifi station SSID and passphrase with the browser

Restart the device and keep the button pressed until it shows the SSID of the wifi access point, spawned by PIXELIX. Search for it with your mobile device and connect.

• SSID: pixelix-<DEVICE-ID>
• Passphrase: Luke, I am your father.

Depended on the type of device you are using for connecting to PIXELIX, you may get a notification that further information is necessary and automatically routed to the captive portal. In any other case enter the URL http://192.168.4.1 in the browser address field.

Use the following default credentials to get access to the PIXELIX web interface:

• User: luke
• Password: skywalker

Variant 2: Configure wifi station SSID and passphrase with the terminal

Connect PIXELIX with your PC via usb and start a terminal. Use the following commands to set the wifi SSID and passphrase of your home wifi network:

• Write wifi passphrase: write wifi passphrase <your-passphrase>
• Write wifi SSID: write wifi ssid <your-ssid>
• Restart PIXELIX: reset

PIXELIX Is Ready

After configuration, restart again and voila, PIXELIX will be available in your wifi network.

For changing whats displayed, go to its web interface. Use the same credentials than for the captive portal in variant 1. In the "Display" page you can change it according to your needs.

User Interface

• The user button provides several features:
  • On short pulse: Activates the next slot.
  • Two short pulses: Activates next fade effect.
  • Five short pulses: IP address is shown.
  • Long pressed: Increases the display brightness until maximum and then decreases until minimum. After that it will again increases it and so on.
• If the display's location is hard to reach, the virtual user button can be used. It is controllable via REST API and perfect for remote buttons like the Shelly Button 1.
• If a ambilight sensor (LDR) is connected, the display brightness is automatically adapted.
• The web interface provides the possibility to install plugins, control their duration in the slots and etc.
• Some plugin's spawn a dedicated REST API, see the web page of the plugin or have a look to the REST API documentation.

Note, the websocket interface is currently only used as a service in the web interface.

Details

For more detailed information, see the documentation.

FAQ

Where to change panel topology of the LED matrix?

First adapt in ./lib/HalLedMatrix/Board.h the width and height according your LED matrix.

In the ./lib/HalLedMatrix/LedMatrix.h file you have to change the member variable m_topo according to your physical panel topology. Take a look how your pixels are wired on the pcb and use the following page to choose the right one: https://github.com/Makuna/NeoPixelBus/wiki/Layout-objects

How to change text properties?

Text properties can be changed using different keywords added to the string to be displayed.
In order to be able to use these keywords, they must be prefixed by a backslash, otherwise they will only be treated as text.

The following keywords are available:

Note

• If theses keywords are used within the sourcecode they have to be prefixed with two backslashes (one additional for escaping).
• If these keywords are used via the REST API all unsafe ASCII characters must be replaced by the respective percent encoding (see also ASCII Encoding Reference).
• The keywords can be combined.

Examples

The display only shows a error code, like "E4". What does that mean?

This is a low level error code. Please have a look into the following table.

How can I use animated icons?

Upload first the bitmap texture image (.bmp) and afterwards the sprite sheet file (.sprite). See the details here. The order is important, because if a bitmap is uploaded, it is assumed that an existing spritesheet is obsolete and will be removed.

How do I know that my sensor is recognized?

1. Check the log output from USB (not via web interface) right after startup (at this point WiFi is not connected yet).
2. Install the SensorPlugin and open the SensorPlugin website. There the sensor should be shown in the drop-down.

Why do I see sometimes values from the LDR in the SensorPlugin, although no LDR is installed?

The LDR pin is configured as input (ADC) and it seems that the pin is floating, because there is the ext. pull-down missing.

How can I use alternative icons?

Find details here.

Is it possible to use a font with 8px height?

There are three font types defined:

• default (6px height)
• normal (6px height)
• large (8px height)

Note, the default font type is "normal".

The font type can be selected per plugin instance in the settings web page.

Example:

{
    "name": "JustTextPlugin",
    "uid": 32690,
    "alias": "",
    "fontType": "large"
}

Not all plugin may support this in case they get conflicts with their layout. If a plugin don't support it, it will use the default font type.

How to configure the date/time format?

The date/time format used by plugins, e.g. the DateTimePlugin or the SunrisePlugin, can be configured in their configuration JSON file. Use the file editor in the web interface to modify it according to your needs. The file can be found in the /configuration folder and the filename is <PLUGIN-UID>.json. The format specifiers following strftime().

Examples:

• %I:%M %p: 02:30 PM
• %H:%M: 14:30
• %m/%d: 11/12
• %d.%m.: 11.12.
• %d - %b: 11 - Nov

You can colorize it by using the text properties.

How to configure my own list of plugins?

The list of plugins which are available depend on the development board you use. Because board with only 4 MB flash don't have enough capacity for all. Or in case of a ESP-S2 (single core) not enough power.

To handle there are several .ini files in the ./config folder:

• configSmall.ini: Used for boards with 4 MB flash.
• configNormal.ini: Used for boards with 8 MB flash or more.
• configSmallNoI2s.ini: Used for boards with 4 MB flash and less mcu power.

Update the one you use for your needs by commenting in or out.

Used Libraries

Issues, Ideas And Bugs

If you have further ideas or you found some bugs, great! Create a issue or if you are able and willing to fix it by yourself, clone the repository and create a pull request. For questions to the community or showing the own Pixelix, the Discord server can be used.

License

The whole source code is published under the MIT license. Consider the different licenses of the used third party libraries too!

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, shall be licensed as above, without any additional terms or conditions.