Posted on May 17, 2011 at 13:47There's at least 100mV uncertainty from the hysterisis alone and I doubt that the thresholds are well defined. Use an external comparator. If you are not fussy about switching levels you could use a CMOS 555 timer powered from the +3.3V STM32 supply. Just tie pins 2 and 6 together and use the output on pin 3.
