I am using a 28BYJ-48 (5V) with a A3967 driver. I have loaded the slave board firmware on to an Arduino Uno. Per this instruction, is it absolutely necessary to cut the red line? If so why? Can I just leave it disconnected? Also, I have connected the slave board and my config looks like this:
G4 RPM_Eng1 s=3
Observing the TX and RX leds on the uno, I don't see any data being transmitted over the serial bus. Am I missing a step?