Introducing a piece of technology into the class canbe a big pain. There are a few ways to do things properly, and lots of ways to head into the non-functional realm of things. Here are a few things that can lead to non-functional:

Serial Connect not Closed. The connection to the manipulators uses a serial connection. Matlab only likes to open it once. If you somehow try to open it up twice, then Matlab will complain and not work. It is a bit troublesome in the GUI. There is a tendency to close the GUI some weird way or to cancel (in the Ctrl-C sense) if somethings seems fishy. All of these prevent the code from properly closing the serial port, so future attempts to communicate with the manipulator fail. Better of hit the “Done” button and to make sure you invoke the shutdown command of the piktul if you are using it in the command line.

Solution: Quit Matlab and run it again.

A Motor Doesn't Work. It might be the case that the servo motor wires got unplugged.

Solution: Check the little microcontroller circuit. Check the underbelly of the manipulator and make sure the extensions are connected.

Motor not Moving. If the motor does not go all the way and you feel that it is getting hot, then something is blocking it and that's not good.

Solution: Try to see what could be causing it and free the physical blockage point. If you are calibrating, and the arm just won't go that far without this issue, then limit the range so that it doesn't get to that point. A workspace limited manipulator is better than an overheating (and eventually broken) one. let me know and I'll try to take a look at it during my free time to fix the issue.