No, use the Arduino serial monitor to watch what the program is putting out. I have changed the output to be readable by a human.
What I wanted to test was if the right MIDI messages are being sent at the right times based on the changes in the two sensors.
So do CTRL-SHIFT-M after you upload the program to open the monitor window. Check that the speed (bottom right) matches what I put in the program - I think I made it 9600. Then try operating the sensors.