The Arduino arrived. I have no electrodes though. But what are electrodes, just some pieces of metal taped to your skin, right? Let's improvise that:
There are two pieces of aluminum foil taped to my skin, held together with blue medical wrap.
The educational material about electromyographs that I've seen described a chain of hardware elements to process and clean up the signal:
But I thought, let's focus on the MVP. Why not simply hook the electrodes straight to the analog input pins of the Arduino with some alligator clamps? Worked fine. I did minimal signal processing in software though, you can find the source code here.
This video shows the myoelectric signal on Arduino IDE's built-in signal plotter: