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.
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
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
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,