Projects / Industrial automation and embedded control
Microcontroller driver for a HUB75 RGB LED panel: preloaded images by discrete inputs, several panel types, PC image utility and adaptation notes.
The task was to make an inexpensive and reproducible driver for a small LED display. A universal media controller was excessive: the display had to show a limited set of known images based on input signals from external equipment.
The customer received a controller board, STM32 firmware, an input-to-image mapping table, a PC utility for image preparation and instructions for adapting the device to new LED panels. The important result is that the project can be maintained further without a full device redesign.
Project materials
Engineering context
HUB75 is a standard-like interface, but real panels differ in addressing, timings and internal row organization.
For different panels, the signal sequence has to be selected and checked on real hardware.
The display had to start quickly after power-up and work without an operating system, media player or complex setup.
The customer needed a way to add images and adapt the driver for new panel batches.
Work done
LED-panel driver schematic and PCB.
STM32 firmware for HUB75 control.
Support for several LED-panel types.
Panel type and mode selection through switches.
Mapping table from input signals to images.
Image storage in flash memory.
PC utility for converting images into firmware format.
Production, flashing and panel-adaptation instructions.
Details
The board connects to the LED panel, receives 5 V power, reads discrete inputs and generates HUB75 signals. Images are stored in firmware, and input combinations select the required screen.
For new panels, addressing and timings can be selected using a logic analyzer and test images. This is especially important when a supplier changes the panel model without full documentation.
This kind of solution fits lift, parking, warehouse and service displays where arrows, modes, pictograms or another limited set of states have to be shown.
Contact
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