STM32F205VB ADC with external reference

[sven]

Posted on October 30, 2014 at 11:17

Hi,

I try to use the ADC with ext ref but it doesn't work...

I use ADC 1 from PA3.

Are there any sample or does have anybody code example?

#whiskey-tango-foxtrot

[Tesla DeLorean]

Posted on October 30, 2014 at 12:49

Ok, from your post I'm not sure exactly what you've got wired up, or what voltage you apply to +VREF, and what in fact is not working. Please describe what you're seeing and what you're expecting.

The Standard Peripheral Library has several ADC code examples, tried those?

[sven]

Posted on October 30, 2014 at 14:52

Hi,

I use a 1,024V Ref at Ref+ and clearyl REF- at vss

But the Values toggle from 0 to 880, nothing between these :(

[Tesla DeLorean]

Posted on October 30, 2014 at 17:46

And the nature of the input signal is what? Please try to present some complete context to your issue, including code, so you stand some chance of get an actual diagnosis of your problem.

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[sven]

Posted on October 30, 2014 at 17:52

There no input source.

If i connect PA3 to GND it seems more often show 0..but not really.

The point of my question is, how  can I switz from internal Reference to external?

I use the Compiler from Microe  and in this ACD Unit is only a internal Ref from VSS to Vdd, And the init Advanced does not work for this µc.

So I need the Information, how can I switch to external Ref