OpenEEG - EEG hardware and software

Hi, I started out with a fully functional 2-channel modeeg, and have written a 
program that displays all 6 channels at once, even the dead ones.

  Now I've assembled 2 more amp boards and soldered the jumpers 3&4 of board #2, and 5&6 of board
#3.  At this point I'm attempting to calibrate the new boards with the u_cal and cal_gnd jumpers
and getting weird results...

  First of all, I only attach one board at a time to the ribbon cable to test its output.  When one
amp board is attached, no other amp boards are attached.  Here's my results:


Board #1 (no calibration jumper wires attached anymore, sorry)
  healthy noise trace on channels 1,2, and (crosstalk?) on 4.
  brushing ribbon cable pins with finger -> some response on all traces.
 

Board #2 
  cal jumpers on channel 3 - no square waves anywhere
  cal jumpers on channel 4 - same as above
  brushing ribbon cable pins with finger -> all traces wiggle except 5 which stays flat no matter
what.

 
Board #3
  cal on channel 5 - inconsistant: no square wave today, yesterday I had a big square wave trace on
two channels, 4 and 6 if I recall.
  cal on channel 6 - no square wave today.
  brush pins with finger -> all traces wiggle except 3 and 6, which are flat.
 

  I looked at the actual numeric values coming out of the channels.  The ones that look flat all
the time are actually varying by only 1 unit, 0 1 0 0 1 1 for example, or 103 102 102 102 103
forexample.

  Am I forgetting to configure or change something for these extra boards?  Do 
they all need to behooked up at once to work?  Are the extra analog inputs on the digital board
tied to some voltage I need to un-tie?

  I should also tell you that the digital board and amp board #1 are modEEG 
version 0.7 while the two new amp boards are version 1.1.  Before I even started though I asked the
group if this should work and the answer was yes.
  
  Thanks if you can help,
  John

Hi,

jcatkeson@... wrote:
> 
> Hi, I started out with a fully functional 2-channel modeeg, and have written
> a program that displays all 6 channels at once, even the dead ones.
> 
> Now I've assembled 2 more amp boards and soldered the jumpers 3&4 of board
> #2, and 5&6 of board #3.  At this point I'm attempting to calibrate the new
> boards with the u_cal and cal_gnd jumpers and getting weird results...
> 
> First of all, I only attach one board at a time

Perhaps this is the problem...

I assume you have followed the instructions to insert IC201 _only_ on the 1st board?

This means that only the 1st amplifier board can work standalone.
The 2nd and 3rd board requires some signals (VGND) generated on the 1st board.

If you want to test the 2nd and 3rd board standalone anyway, you have to 
temporarily insert IC201 and any other omitted parts.


...
> 
> Am I forgetting to configure or change something for these extra boards?  Do
> they all need to be hooked up at once to work? 

Yes.

> Are the extra analog inputs
> on the digital board tied to some voltage I need to un-tie?

No.

> I should also tell you that the digital board and amp board #1 are modEEG
> version 0.7 while the two new amp boards are version 1.1.  Before I even
> started though I asked the group if this should work and the answer was yes.

This should be no problem.

Regards,

	Joerg