Thanks for getting back to me so quickly Dave!
I just built a cable that simply is a "loop" (3 pin cable where the two outside pins are connected.)
That should ground out the ADC line and return a value of "0."
I tested this with a voltmeter again, to make sure it wasnt a stupid error on my part.
I then plugged it into ADC.7 on the back of the board, the farthest away from the edge that has the power jack.
when I do "i2c-io 0x0b get ADC.7" I STILL get "1023."
Whats going on here??? Do I have to set some register on the ATmega128? I am using a standard SVN copy of i2c-io that I havent modified btw.
>From: Dave Hylands [mailto:firstname.lastname@example.org]
>Sent: Thursday, November 2, 2006 10:22 PM
>To: 'General mailing list for gumstix users.'
>Subject: Re: [Gumstix-users] Fwd: ADC pins on Robostix
>> > > I am working on a project using robostix/gumstix boards as the embedded
>> > controller. I for some reason unknown cannot get the ADC pins on the
>> > robostix to function. Using i2c-io from the gumstix, they always return
>> > "1023" no matter what the actual value is according to a volt meter. Yet,
>> > everything else on the boards functions as normal.
>> > >Is there some register I have to set first, a jumper to set?
>> Hmm. They should work fine. I will double check just to be sure
>> tonight when I get home.
>I verified that everything does in fact work as expected.
>One thing to be aware of is that the ADC pins on the top of the board
>are labels as 1-8, but the signals labelled on the back of the board
>It's the labels on the back of the board that are used by the ATMega
>processor. Being off by a pin has been encountered by several people.
>Also make sure that you've plugged in the the power jack into the
>robostix and not some other poer jack on another board.
>Vancouver, BC, Canada
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