We demonstrate a coherent polarization beam combination of two-channel picosecond pulses based on a microcontroller-based phase-locking method. This simple and low-cost technique enables easy programming and automatic relocking of the relative phases between two fiber amplifiers. The total average power of the combined laser is 30.4 W, corresponding to a combining efficiency of 91%. The microcontroller-based phase-locking method provides a competitive solution for robust and programmable control of phases in the active coherent polarization beam combining system.