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Delays
09/16/2014 at 15:10 • 0 commentsDue to a medical issue in my family I haven't had time to work on this for a couple months. But that's about to change! Now I just need to run to frys to get assorted resistors/caps and we'll be in progress again.
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The Output works
06/28/2014 at 02:42 • 0 commentsWell, that was fast. I got a nice pretty sine wave output from the board at a selectable frequency. Don't have a scope, but plugged it into some speakers and sure enough it sounds like a clean tone. Of course, I'm not sure it matters for this application. It makes the most sense to pump the same signal to 2 electrodes (the same ones used to detect eye movement) and use a 3rd as a reference, since I don't really have a simple way to supply true alternating current in a regulated matter. I'm pretty sure the brain has a frequency following response at least for a little while (long enough to "wake" the necessary functions), so true alternating current shouldn't be necessary. Waiting for an extra set of lm317s to come in so I can test to see if current regulation wrecks the signal. I also just ordered the instrumentation amplifiers, but those won't come for almost a month (cheap from china, expensive and still slow from everywhere else).