Proof of Concept: multiple signal input processing

First, we did single signal input processing. You know, to get the hang of it.

• connect electronic test cables from computer's signal out put to Arduino (see image 1)
• two cables to Arduino, one in A0 and one in ground
• set up signal on easy scope 

• connect Arduino to computer and set up sampling rate
•  remember to install the drivers!
• Put in the following code

 

• Start the signal generator on easy scope
• the signal looked weird. It only looked weird when we plugged it into the Arduino. The solution was to plug the ground into the breadboard. EDIT don't do that.
• 300, 14400, 28800 didn't work.EDIT  these still don't work after later edit/solution.  The rest worked until anything past 19200 froze the computer:( 
• we think this is because the serial monitor couldn't handle those speeds, so we researched alternatives to the serial monitor (standard with the Arduino program.)
• We discovered this in addition to an Arduino graphing library. Why aren't we using this (the graphing library) already? I guess we'll find out! 


• The graphing library would allow us to either graph from serial (not helpful) or 
• EDIT the solution is to print on new lines, the serial monitor doesn't handle horizontal scrolling well 
• The highest sampling speed (115200) works! We copied a bunch of the data and graphed it in MatLab but it looked like a wandering sine wave (sad).



Sad wandering sine wave










• Upon re evaluating what we did before we realized they hall had to be in the same ground.






• Additionally, we noticed that our signals would get cut off at 700 , so, we changed our peak to peak voltage output from 5 to 2 and it all fit so we had a full signal! This would be disturbing (in case we needed a larger peak to peak voltage output) but since it worked from a lower ppv, we attributed it to the arduino's Ato D converter, and since we will be using a different one, we let it go...for now...
• Then we changed the sampling delay from 2ms to .2ms to give us a cleaner signal
• Finally, we raised the frequency to 54 Hz (which is what we needed to be clinically applicable) and it worked! check it out :D
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