I try to drive WS2812B LEDs with the STM32F100 chip. I read a lot of sources and stopped on the following thing.

I have a repository with latest version of code: https://bitbucket.org/ruslanpopov/stm32-ws2812b-dma/commits/branch/armka

I did debug print to USART and saw that everything is OK there.

I connected a Saleae-like analyzer and different version of reality that also is proved by the LED's behaviour.

Enter image description here

I sent RGB=0x550000. The PWM buffer has the right values. But the analyzer takes RGB=0x660000. I don't understand how 0b01010101 becomes 0b01100110. What is the reason?


1 Answer 1


The root of problem was in 'dma_source' variable. Renaming it to '_dma_src' solves problems. Video on VK.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.