Pots not working properly

Testing/Troubleshooting
1

Thanks for all the previous help.  Now, I have another problem.  I was able ground my AIN properly so random MIDI data jitter no longer occurs.  I have 8 pots connected.  My problem is that when any one pot is turned left a little, it emits the following data very quickly:

Tick     BO  ST D1 D2 CH Event

014ffd00 000 ffb2 5b 7e 03 CC(91)

014ffe00 000 ffb2 5b 7f 03 CC(91)

01500100 000 ffb2 5b 7d 03 CC(91)

01500180 000 ffb2 5b 7e 03 CC(91)

01500180 001 ffb2 5b 7f 03 CC(91)

01500380 000 ffb2 5b 7e 03 CC(91)

01500480 000 ffb2 5b 7f 03 CC(91)

01500700 000 ffb2 5b 7e 03 CC(91)

01500780 000 ffb2 5b 7f 03 CC(91)

I noticed that the channel number above corresponds to the pot I turned.  The CC(91) is the same for whatever I turn.  D1 is one less than the channel number, so it changes for each pot.  D2 is always 5b.

By the way, I’m using MIDIbox64 application.

When I return the pot to the right all the way, the MIDI is silent again.  

I should actually make something a little more clear.  I’m actually using CV expression pedal, not plain pots.  Also, I’m not sure what its rating is.  Does the rating matter?  Can I test for rating somehow (I have a multimeter)?  If they are the wrong rating, is there some way for me to fix my setup or the pedals so everything’s compliant?  Or did I just set things up wrong to begin with?

2

Do you have 3 wires going to the pedal?, or just two? You need 3 one for groud one for +5v and then the one that goes to the AIN.

Justin

3

yeah, I have 3 wires.  

Doing a conituity test with combinations of the three wires, I get the following results (pardon my terminology).

Pedal down:

+5 and PIC= closed

+5 and ground= open

PIC and ground= open

Pedal up:

+5 and PIC= open

+5 and ground= open

PIC and ground= closed

HMMM…

Checking some contacts I think I found a hole in the ground path.  Gotta heat up the old iron.

4

That was it.  Just one ground contact.  My expression pedals express.  This is very cool.  MIDIbox rules!  Thanks, Justin.  YOur comment pointed me in the right direction.

5

Glad to help. I forgot to tell you:

Can I test for rating somehow (I have a multimeter)?

To test the rating of a pot, you measure the resistance between the middle lug and one of the other lugs. The highest resistance you get is the rating. So if you get 9.9k ohms, you have a 10k pot.

Justin