Hi
I bought the simple motor controller 18v15.
I tested it with the Pololu Simple Motor Control Center on WIndows7 using usb connection. I could make my dc motor turns forward and backward.
As I moving the speed cursor along to change the motor speed, an error message box appeared, the controller stops responding and the motor keeps rotating on until the power is disconnected.
Then I tried to reconnect the controller another error message box appeared.
Then I unplug the usb and plug it back to try again the whole process repeated again.
That looks like the type of error that could be caused by electrical noise on the USB line. Is the blue electrolytic capacitor installed on your motor controller? These come installed on the fully assembled version of the board, but you have to solder it on yourself on our basic version. If your USB cable runs alongside any of the motor power supply or motor leads, you might try to route your cables in a way that separates them more. Using a powered USB hub or a USB cable with a ferrite bead can also help with noise on the USB port.
I searched on line for motor noise reduction and found an article “Dealing with Motor Noise”(https://www.pololu.com/docs/0J15/9) on Pololu website. I followed the suggestion and soldered three 0.1uF capacitors between the to leads of the motor and between the 2 leads and the motor case. The problem disappeared.
Thank you for pointing to the cause of the problem that made it a lot easier for me to resolve the problem.
