Posted on May 17, 2011 at 12:58I have a precision 2.500V source connected on Ain6 (pin 16 of STM32F101C8T6).
After I reset, I can read consistently the same value (with 1 or 2 bit fluctuation) for as long as it remains on. Example read value is 3106.
If I turn off/on or reset, then I read consistently a different value. Example read value 3087.
This is happening only for that channel. I have connected the same 2.500V to another input (Ain4 or Ain7), the captured value is consistant after every reset.
I was able to recreate the same thing without resetting by calling ADC_RegularChannelConfig( ADC1, ADC_Channel_17, 10 , ADC_SampleTime_239Cycles5); It actually doesnt matter which ADC channel is selected or which order it is given. After this function is called, the read value can be different by up to 20.
Is anyone aware of a problem with the ADC and that particular channel?
I have tried a second board and the problems is there too. The ADC is configured to do the conversion using DMA.
Thanks
Cosma
[ This message was edited by: cosmapa on 03-01-2009 17:27 ]
