Thanks for your help!
I actually switched from using just Serial to SerialUSB because of the faster transmission rate but maybe that isn't being handled well by my computer. Would it be better to use the timer as you've suggested to make the transmission rate more manageable or to switch back to using Serial instead of SerialUSB and increase the baud rate/decrease the data transmitted?
I read about making Serial faster and ideally I would like to keep a sampling rate somewhere near or above 4 samples/millisecond to get a nice plot (I'm observing something that occurs in about 6-8 milliseconds), but that might not be possible... Are there any other solutions out there that might help keep a sampling rate that high? Or should I look into the computer side of things since it seems to manage it at some times and not at others?
Thanks again!
Edit: I was also looking at other ways of storing the data on my computer if that might speed it up (i.e. if the hold up was Processing), and I was wondering what might be the fastest way to store all of the values I'm getting in a way I could use with Excel?