2022-11-24 01:28 PM
I have found the address of VREFINT_CAL for other processors. THE STM32F205 seems to have the vrefint adc channel on ADC1_IN17 but I can't find the address for the factory cal value.
Thanks,
Roger Kelly
ROM Communications
2022-11-24 11:37 PM
Welcome, @RKell.6, to the community!
This calibration feature for the ADC was only introduced on the STM32F3, the STM32F1 and STM32F2 do not have it yet.
Does it answer your question?
Regards
/Peter
2022-11-25 12:41 AM
Hi Peter,
Interesting, didn't know about this. I'll add it to my collection of gotchas... :)
However, one remark, the 'F40x/41x does have VREFIN_CAL (as well as TS_CALx), and it predates 'F3. In fact, I'd chalk this one up as one of the rather few 'F2/'F4 differences (in addition to the obvious one, the processor core).
It also means that it's not present in 'L1 either, doesn't it.
Jan
2022-11-25 01:55 AM
OK, yes, the STM32F3 came after the STM32F4, both of which already have the calibration value, just like the STM32L1, F0, etc. by the way. But from today's perspective, only those who witnessed the early days and the gold rush of the time probably know that, right?
Presumably, historically, the reason for measuring such a calibration value and storing it in ROM was that you really only need something like that for absolute ADC measurements, whereas with the first families STM32F1/F2 the measurements were intended to be done mainly ratiometric, to eliminate the error influence of the supply voltage.
/Peter
2022-11-25 01:09 PM
Thanks for the answers! No wonder I couldn't find the info in the data sheet. It isn't there ;-):>