I'm sure you know this, and perhaps it's way too late, but still: the STM32s can certainly use DMA to write to GPIO pins. See for instance [1] (not my project,

I'm sure you know this, and perhaps it's way too late, but still: the STM32s can certainly use DMA to write to GPIO pins. See for instance [1] (not my project, just a random search hit that seemed nice). [1]: https://github.com/mnemocron/STM32_PatternDriver https://github.com/mnemocron/STM32_PatternDriver