What ADC channel are you using, external (A0-A7) or internal (>7)?
does the conversion require stable reference voltage (if so, is your
application wiring to AdcReadClientC or Msp430Adc12ClientAutoRVGC()?).
Do you see the same result when you use
tinyos-2.x/tos/chips/msp430/sensors/Msp430InternalVoltageC?

Jan

On Wed, Jun 18, 2008 at 9:09 PM, Michael Schippling <[EMAIL PROTECTED]> wrote:
> One possibility is that the ADC needs a certain
> settling/sampling time prior to each conversion
> and after channel changes. Perhaps the timing is
> off the first time around...
>
> MS
>
> Dimas Abreu Dutra wrote:
>> Eric,
>>
>> I'm not positive it isn't the hardware, but I am POSITIVE I have the
>> voltage that should return around 0x0916 adc counts. I also have run
>> this on two different motes (both invent) and noticed the same thing on
>> adaptations that Urs Hunkeler did of the original tmote invent drivers.
>>
>> It can be some hardware feature (capacitor transients, etc) but if it
>> was, the ADC drivers should start it on the boot sequence, so the first
>> readings would not be erroneous. I can solve this on my own, with a
>> dummy reading just to clear that, but it wouldn't be a very elegant
>> solution and this can be a problem to more people on the future. I did
>> read some of the msp430 datasheet, but there is too much detail and
>> complicated state machines, and the code of the msp adc modules are very
>> complicated too. I can inspect more, but I think that maybe it should be
>> clearer for people who had more hands-on contact with the adc.
>>
>> ~Dimas~
>>
>> On Wed, Jun 18, 2008 at 1:55 PM, Eric Keller <[EMAIL PROTECTED]
>> <mailto:[EMAIL PROTECTED]>> wrote:
>>
>>     Are you positive it isn't hardware?  What version of TinyOS are you
>>     running?
>>     Eric
>>
>>
>>
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