nobikes:
The issue is defiantly not impatient students, i try to do it with their boards and i get the same error. My money is on Wandersons conclusion of electrical noise. The question is what can be done to stop the electrical noise? and what pins would most likely cause the com port in use problem if they were exposed to the electrical noise?Motor shield files
If your using a usb connection there are only four pins (2 data and power). The electrical noise generated by motors affects everything in the circuit.... The best solution is to isolate the motor shield in particular isolate the motors power supply. A separate regularltor works best but lc filters can help as well.