This is a tiny Elixir/AtomVM demo for the Seeed XIAO-ESP32S3 featuring:
- A 480×320 ILI9488 LCD driven over SPI
- FAT-formatted SD card support with automatic image loading
- A lightweight HH:MM:SS clock overlay
- Resistive touch input via XPT2046/ADS7846 (with a small on-screen cursor +
x:yreadout)
This project uses a custom breakout board designed for the XIAO-ESP32S3, with connectors for:
- ILI9488 LCD
- XPT2046/ADS7846 touch controller
- SD card (shared SPI bus)
Two board revisions are supported:
- v1.5 or lower — original wiring
- v1.6 or higher — same board, except LCD-CS and SD-CS are swapped
These are the boards shown in the photos below.
Base wiring for v1.5 (and lower):
| Function | XIAO-ESP32S3 pin | ESP32-S3 GPIO |
|---|---|---|
| SCLK | D8 | 7 |
| MISO | D9 | 8 |
| MOSI | D10 | 9 |
| LCD CS | — | 43 |
| Touch CS | — | 44 |
| LCD D/C | D2 | 3 |
| LCD RST | D1 | 2 |
| SD CS | D3 | 4 |
For v1.6 (and higher), these two swap:
- LCD CS → GPIO4
- SD CS → GPIO43
# 1. Install dependencies
mix deps.get
# 2. Select board version (default: v1.6)
export PIYOPIYO_BOARD=v1.5
# or
export PIYOPIYO_BOARD=v1.6
# 3. Build the AVM image
# NOTE: Run `mix clean` whenever you change PIYOPIYO_BOARD.
mix clean
mix atomvm.packbeam # outputs _build/atomvm/main.avm
# 4. Flash to the ESP32-S3
mix atomvm.esp32.flash --port /dev/ttyACM0 --baud 115200- Raw RGB888 (no header), top-left origin
- Exact size: 480 × 320 × 3 = 460,800 bytes
- Place the files at the SD card root; a fallback
priv/default.rgbis used if none are found