This ESP32 Arduino library for an RGB LED (HUB 75 type) Matrix Panel, utilises the DMA functionality provided by the ESP32's I2S 'LCD Mode' which basically means that pixel data can be sent straight from memory, via the DMA controller, to the relevant LED Matrix GPIO pins with little CPU overhead.
You need to install [Adafruit_GFX_Library](https://github.com/adafruit/Adafruit-GFX-Library) from the "Library > Manage Libraries" menu.
## Patching GPIO to avoid eratta of ESP32
You should patch the `tools/sdk/ld/esp32.peripherals.ld` to avoid random pixel noise on the display as following:
```
/* PROVIDE ( GPIO = 0x3ff44000 ); */
PROVIDE ( GPIO = 0x60004000 );
```
Please refer section 3.3. in https://www.espressif.com/sites/default/files/documentation/eco_and_workarounds_for_bugs_in_esp32_en.pdf for more details.
The panel must be powered by 5V AC adapter with enough current capacity. (Current varies due to how many LED are turned on at the same time. To drive all the LEDs, you need 5V4A adapter.)
A [typical RGB panel available for purchase](https://www.aliexpress.com/item/256-128mm-64-32-pixels-1-16-Scan-Indoor-3in1-SMD2121-RGB-full-color-P4-led/32810362851.html). This is of the larger P4 (4mm spacing between pixels) type.
Refer to the excellent PxMatrix based library for how to wire one of these panels up (in fact, it's probably best to first get your panel working with this library first to be sure): https://github.com/2dom/PxMatrix
You'll need to adjust the pin configuration in this library of course.