Arduino for STM32

Thanks, I've tried SoftWire, with the same result. Looks like @ag123 said, I'll have to get oscilloscope or use another stm32 to see what's going on there.

It happens somewhere in ReadPassiveTargetId. The strange thing is, that if I don't provide card, it can work for long time without failing, but if I do, it fails in next 1 up to 4 loop execution.
I use
https://github.com/rogerclarkmelbourne/Arduino_STM32

Looks like I'll have to get ST-link to do ...

I've also tried 3v3 configuration (pn532 power supply + pullups), but with the same effect. As PB6 & 7 are 5V tolerant, i thought that i'd give it a try.

Hi,
I'm playing with pn532 board nad bluepill. For some time, I've tried to make it work, but (almost) without success.
From time to time, bluepill is not able to discover pn532, when it happens, I need to unplug 5V from pn532, and then it starts working.
But not for long. After reading card(one on ...