I was experimenting with hooking up my Roomba to an Arduino the other day, but discovered that I didn’t have the proper cable for the Roomba’s serial port. Most of the tutorials I’ve seen require cutting up a mini din cable and hooking the individual wires inside to the appropriate part of your Arduino circuit. I had a similar cable that wouldn’t quite work for this, so I took it apart to see how the wiring worked. Turns out (unsurpisingly), each pin on the cable is attached to it’s own wire. The only weird thing is that the metal ring surrounding the pins is conductive as well, and is also connected to a wire.
Anyways, I decided to try sticking the jumper wires right into the corresponding pin holes in the Roomba’s serial port, and it actually worked perfectly. This set up isn’t ideal because whenever I want to disconnect the Arduino from the Roomba I have to remember where each wire was connected in the serial port, but it’s a decent solution if you want to get something up and running and don’t have the right cable laying around.