Blocking i2c v1 hangs on stm32f103 when no pullups are used

[DCNick3]

It loops forever here

while self.check_and_clear_error_flags()?.sb() == i2c::vals::Sb::NOSTART {}

Probably because the chip doesn't confirm that it has generated START condition when no pullups are used?

This probably can be handled in a way similar to the way stm32f1xx-hal does it, always having a bound on a busy wait. Maybe even port the implementation :thinking: