Hello all,
     I breadboarded a 7107 so that I could make some changes as I went=20
along. I have it sitting here and working. Pins 35, 32, and 30 have to=20
be interconnected and hooked to ground. You also need to put a high=20
value resistor from the input connection to the 1 meg resistor that is=20
connected to the IN HIGH pin. In the manner that you said Robert. I=20
checked all three of my chips and they are good. The problem is a=20
mistake on my board. I'm going to quit for the day.
Thanks,
rich!
P.S. Marcel, thanks for the tip on the datasheet but I was already using it=
..
rich!

On 5/4/2014 9:10 PM, Marcel Duchamp wrote:
> You cannot measure "a couple of volts" with this circuit; it is designed
> for +/-200mV fullscale.  It 'probably' won't damage it to try it as
> there is a 1Meg input resistor.  But at anything it thinks is over
> 200mV, it will display + or - 1 with the other digits blank. Your
> circuit will probably show this even if it is working properly if you
> leave the input floating.
>
> To trouble shoot further, get a good datasheet such as the one from
> Intersil. Maxim's is a photo-copy and sux.  Then go to Intersil's
> website and get some of the ap-notes on using it. In particular, get
> from this page:
> http://www.intersil.com/content/intersil/en/products/other-analog/special=
-analog/integrating-display-output-a-d-converters/ICL7107.html
>
> this document:
> http://www.intersil.com/content/dam/Intersil/documents/an05/an052.pdf
>
> which shows a wealth of trouble shooting and debugging info. Read it
> carefully.
>

--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.