By Renpeng Zhang
For the chassis eagle schematic, I choose to use two PCA9685 I2C expanders because one doesn’t have enough PWM pins for all our needs. We also used six VNH2SP30 motor driver for our motors. We use the PWM input from the I2C to the PWM pin in the motor driver. We left the shaft encoder pins on the second expander for the reading of the values for the RPM of the motor. We have left the pins for the current sensing on each of the motor driver so that they will be connected to the analog input of the Arduino to get the current of each motor.