the serial port protocol mainly transmits real-time data from the electronic speed controller (ESC) to the flight controller, handles ESC firmware updates, and has no other functions.
CAN:
CAN communication transmits real-time data from the electronic speed controller (ESC) to the flight controller. Additionally, the flight controller can control the ESC using CAN throttle. The CAN version of the ESC supports dual redundancy control via both PWM and CAN throttle.
The real-time data includes output input throttle (PWM) control signals, motor speed, ESC voltage, ESC current (input current and phase current), ESC temperature, and ESC capacitor temperature.
