Oct 11, 2026, 1:06 AM

Ah now with controllable brightness I can take a much better picture of the display with a web cam. Turns out the display wants a 10 kHz PWM signal for good results. (1MHz clock with 100 clock periods => 10 kHz adjustable period waveform) It will go all the way down to 1% PWM, but doesn't "light up" from full dark until you get to 8% PWM.

Picture of an LCD Display on an STM32U5G9-DK2 project board displaying "graph paper" (a sort of quadrule design) at a low enough intensity that the auto-brightness of the Webcam taking the picture can focus and resolve the display clearly.