A challenging smart car

Introduction to the car:
It uses HC-SR04 ultrasonic distance measurement and obstacle avoidance. It
uses Uxin’s Bluetooth module to remotely
control the car’s walking speed and more gears through Uxin’s Bluetooth module
. There are two white LED lights in front of the car, which can better match the image of the car
. The expansion board has two independent buttons, KEYS and KEYM, which are used to start and switch between sports modes. The KEYS button has an LEDS indicator light, and the KEYM button has an LEDM indicator light. Pressing the button can switch the status of the light.
 
Motor drive module: Four RZ7889 chips are used to control each wheel. The motor is an N20 reduction motor, and the model is 6v 60 rpm.
Core board pins:
Buzzer schematic: Equipped with a buzzer, which can be used to sound when encountering obstacles. alarm.
Power circuit:
PCB board front and back: