search

openwch / arduino_core_ch32

Core library for CH32duino
252 stars 42 forks source link

micros() is flawed on CH32X035 (and other targets too probably) overflow management issue #148

Open 0x0fe opened 5 hours ago

0x0fe commented 5 hours ago

micros() has a seriosu problem on CH32X035, rendring it unusable, this affects any functions that reliles in this function, bascially it contantly overflows or the overflow is not handled correctly, as a result when used to get short timings intervals (less than a millisecond) with a time stamp and substracting the current value to the time stamp a few hunders us before we will often get totally wrong and even negative values. That is, it will randomly return a timestamp inferior to the timestamp taken few hundred microsecond before. Obviously that is not how it is supposed to work, micros can overflow after a while, but it should be 70 minutes, not few milliseconds or even less. And even then, the overflow should be handled in the micros function so that it never appears to the function user.

maxint-rd commented 2 hours ago

Could this be related to #65 where @Khalinda found some sort of solution? Also related to #114?

0x0fe commented 1 hour ago

@maxint-rd possibly, i did not notice it was counting down as in the first issue though. It counts up, except randomly the new value is lower than the previous value (with few hundred us interval).