The four axis control architecture based on microcontrollers. Straight lines are logic lines; dotted lines are analog lines; dot-dot-dash lines are power supply lines. The high-level hand controller (HLHC) is directly connected to the external world both with a RS232 and SPI bus. The HLHC deals with the low-level motor controllers via an additional SPI bus. The LLMCs are directly connected to H bridge drivers (H) delivering current to the DC motors using pulse width modulation (PWM) technique.