ultra Posted November 26, 2009 Report Share Posted November 26, 2009 here's a question i haven't been able to find documented anywhere: what is the ain resolution for the core32? thanks, ultra Quote Link to comment Share on other sites More sharing options...
nILS Posted November 26, 2009 Report Share Posted November 26, 2009 12bits Quote Link to comment Share on other sites More sharing options...
baptistou Posted November 26, 2009 Report Share Posted November 26, 2009 I think it's 12 bits but I haven't tried it yet, I should do that by the end of the week. I think also that as the Core32 is powered by 3.3V the AIN range is from 0 to 3.3v can anybody confirm? Then I heard somewhere that its easy to get jitter (12 bits resolution on a 3.3V range means 0,8 millivolts steps) and to avoid this it's better to uses shielded cables between the pots and the AINs, and between the AIN and the core, or to reduce at maximum the wire distances. Baptistou Quote Link to comment Share on other sites More sharing options...
baptistou Posted November 26, 2009 Report Share Posted November 26, 2009 (edited) nILS you are quicker than me for pressing post! :thumbsup: Edited November 26, 2009 by baptistou Quote Link to comment Share on other sites More sharing options...
philetaylor Posted November 26, 2009 Report Share Posted November 26, 2009 I have had quite a few jitter problems using USB power and unshielded cables so yes I would definately recommend using shielded cable and external power. If you are using an AINX4 then I believe that the range is 0-5V but don't quote me on that! The latest updates that TK has done have helped to reduce jitter by setting an idle threshold. Cheers Phil Quote Link to comment Share on other sites More sharing options...
seppoman Posted November 27, 2009 Report Share Posted November 27, 2009 If you are using an AINX4 then I believe that the range is 0-5V but don't quote me on that! I think that's not right, the AIN uses analog multiplexers that only do routing but don't change the voltage levels. The STM32 runs at 3.3V and usually an ADC can't make sense on voltages that are beyond its supply rails. Probably you can't damage anything by applying 5V but everything above 3.3V will read as max value. S Quote Link to comment Share on other sites More sharing options...
philetaylor Posted November 27, 2009 Report Share Posted November 27, 2009 You qre quite right.... From the core_stm32 page: ADCs cannot be supplied at 5V, 3.3V is the limit. This increases the signal/noise ratioCheers Phil Quote Link to comment Share on other sites More sharing options...
bilderbuchi Posted November 27, 2009 Report Share Posted November 27, 2009 (edited) shouldn't this _decrease_ the SN ratio? i.e. noise gets stronger? :yes: Edited November 27, 2009 by bilderbuchi Quote Link to comment Share on other sites More sharing options...
TK. Posted November 27, 2009 Report Share Posted November 27, 2009 shouldn't this _decrease_ the SN ratio? i.e. noise gets stronger? :yes: Of course! Thanks! :) Best Regards, Thorsten. Quote Link to comment Share on other sites More sharing options...
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