I have an mBot Ranger and also a makeblock bluetooth controller. . From the makeblock website I downloaded the sample program “Official BTC for Ranger”.
After I uploaded to the mBot ranger, the program worked perfectly as long as the ranger was still connect to my PC via USB cable. If I disconnect the USB cable, the buttons to control motion do not work correctly. If I push the ‘forward’ button, instead of moving forward smoothly, it moves forward for a second, stops for a second, moves forward for a second, etc. Same thing for reverse, left turn, and right turn.
I do not understand why being connected to my PC with a USB cable would make the program work different, but that is what happens.