I am trying to convert a RC car into autonomous car using Arduino Pro Mini 5v 16 Mhz. I have done this with UNO and Adafruit motor shield 1.0 with 4 gear motors and one micro servo for mounting range finder sensor. That worked fine.
Need to mention here that originally the RC car was using 5 AA cells for 2 motors and its RC reciever which looks like a customized motor shield as well.
I tried to move everything to Arduino Pro Mini 5v, and motor shield v1 to reduce space. Now how I wired everything.
- Uses 8 AA cells to power the motor shield on EXT-PWR input.
- From EXT-PWR in motor shield one wire goes to RAW in Pro mini.
- From Pro Mini, VCC connected to +5v on motor shield.
- One micro servo having range sensor getting its current from motor shield.
- Motor shield has to run two motors, 1 for rear wheels and 1 for turning front wheels. (they are small motors look like 3v)
Now when I turn on the power the motor sometimes run and sometimes sound like bee and no movement. That also cause the L293d chip on motor shield becomes very hot and I think I have burnt one yesterday and replaced it from another motor shield. Same for servo it sometimes move or not move but sounds like hmmmmmmmm. The Arduino power light on and red. But sometimes it flickers and other light is also on and off.
At this point I have no idea whats wrong here. I changed the input voltage to lower but no progress. Tried to disconnect the 5v input from Pro Mini to motor shield and give 9v input to motor shield but nothing works. Please suggest best or correct power distribution in this case.