XPT2046 fix

Your clone chip is being disarmed.

On cheap SPI touch panels, the kernel driver echoes one byte back at probe. A genuine chip ignores it. A clone reads it as a command and switches its pen interrupt off.

GitHub

Panels: waveshare35a · MHS35 · tft35a · piscreen
Stack: Shell
License: MIT

start bit

Genuine reply011111110x7F

Clone reply111111110xFF

The driver echoes this byte back. With the start bit set, the clone reads it as a command: PD=11, pen interrupt off.

Fig. 01Captured with SPI tracepoints. Pi 5, kernel 6.18.34.

Install

git clone https://github.com/Robinbinu/xpt2046-clone-touch-fix.git
cd xpt2046-clone-touch-fix && sudo ./install.sh