The Actobotics Motor Driver can be purchased pre-assembled or as a kit. (Photo credit: Actobotics)
This tiny board can control two brushed DC motors. At 1.3″ x 3″ it also fits easily into an Actobotics channel or secures to the outside. Assembled, it weights only 0.60 oz.
The has four operating modes: digital speed control (RC), analog speed control, split and servo. Other features include under/overvoltage shutdown, an over voltage clamp, thermal shutdown/protection, cross-conduction protection, as well as current and power limitation.
The unassembled Dual Motor Controller board costs just $89.99.