I have a project with a DC gear motor, and some limit switches, all of which are fed to my arduino with a 6 conductor cable about 6 feet long. The DC motor opens & closes a door, which triggers the microswitches. I'm having trouble with false detection on the limit switches. My arduino is using internal pull ups on the pins monitoring the limit switches, but the motor running must be causing some kind of noise, and the 6 foot length of cable which feeds the little motor, and the limit switches is not twisted pairs. I put a 0.1uF cap on the motor itself which greatly helped, but I still get misfires on the limit switch. I'm going to swap out my cable to a cat5 cable with twisted pairs, which I hope will fix the problem.
Incuded is a photo are my setup.
My main question: I have a pocket DS203 scope, and would like to learn more about using it. I would think that I could measure the noise by connecting it to the motor terminals? I'm kinda at a loss to know how to set it's settings. I've googled for tutorials on such, but am coming up short. The DC motor is a 12 volt motor. If anyone has a DS203 and could advise on some basic settings to test this out I'd really appreciate it.