Problem: Me or the board?

[k-maub]

I'm trying to use the interface board to measure resistivity (using analog in).  It seems that no matter what I do, I either get 5 V or a random reading (if 5 V is not connected).

I think this should be a good test:
5 V -- 10 K ohm -- AnIn -- 10 K ohm -- 0 V

I would think this would turn 2.5 V (or 512 raw value).  Right?  No?  But all I read out is ~5 V.  If I connect the analog in to ground, I would think I'd read raw = 0, but no dice.

Please enlighten me to what I am missing.  Unfortunately, there is no circuit diagram in the wiki for this like there is for a digital input...

Help is appreciated!

Thanks.

[jason]

Your voltage divider circuit looks correct.  Make sure you have the channel set for I/O mode.  How are you checking the value, via a widget or the module settings page?

[k-maub]

Ok, thank you for the timely reply.  You gave me the impetus to go back with a multimeter, and sure enough, I am the problem.

It turns out that the wire to ground had been bent back and forth too many times, and had broken, BUT the insulation had held, hiding the fact.

I figured it out, but I appreciate your help in confirming that my understanding of the circuit was correct.

Back to goofing off with it!