Open Robotics PCB

During my time at Open Robotics, I designed and assembled a PCB for the team's SCARA robot project. This PCB had 3 main components, power management, motor control, and I2C communication with AS5600 magnetic encoders. This board was designed to provide power (24V 4A) to 4 stepper motors on the robot, and included a buck converter circuit using the LM2576 IC to provide 5V power to servo motors and all low voltage (3.3V-5V) components when the microcontroller is not powered by USB. Furthermore, this PCB incorporated 3 TMC2209 stepper drivers for controlling NEMA 17 motors, and a TMC5160 for controlling a higher-power NEMA 23 motor used on the robot's linear actuator. These 4 stepper drivers can all be programmed via the microcontroller installed on the board. The SCARA robot incorporated closed loop motors control using AS5600 magnetic encoders, allowing for higher accuracy and repeatability for the robot's movements. These magnetic encoder chips communicate via I2C, however due to their similar address, the TCA9528A I2C multiplexer was used to enable the microcontroller switch between the chips and read each of their registers. Throughout this board, decoupling capacitors were used in parallel with the high voltage input to the stepper drivers to reduce power supply noise, and pull up resistors were used for the I2C circuit connecting the encoders to the TCA9528A. After manufacturing the PCB, I used a hot air station to solder all SMD components, as small as 0402 resistors, and used a soldering iron for soldering the header connectors.