Fun tip: You see how zig zaggy my video's baseline signal is?
It is supposed to be a flat when you do not move.
Here are some reasons why you may have noise in your signal.
1) Don't wear headphones or any other electronics when you are taking your ECG or EMG. (In the video I was wearing headphones)
2) Unplug your laptop charger.
3) Wait at least 30 seconds and see if your signal levels out.
Here is an example of what it may look like if you just need to wait.
It may take time to level out. (like 20 seconds)
Setting the Threshold Value
Everyone's muscles are different and your electrical signal will be different than mine. So, you need to find your own Threshold.
I set my threshold to 260 because my when I did not move, my graph's line is at about 255. My twitch caused it to go to a little above 260. Your threshold needs to be above your flat not moving line but below your twitch peak line.
You will have to set your own thresholds for the high and low values based on your muscle signal.
You will have to set your own thresholds for the high and low values based on your muscle signal. I picked 400 for high because when I moved my arm up the numbers always went above that and I picked 200 for low because moving my arm down always made numbers below that.
Tip: You need to power a lot of items with this activity but the Arduino board only has so many GND and Voltage holes.
When you need to power many electrical components, plug all the red + wires into the positive breadboard rail and all of the - black wires into the - blue breadboard rail.
Do not forget to power the rail by connecting the Arduino's GND pin with a black wire to the blue - rail and a red wire from the Arduino's 5V pin to the red + rail.