【LiChuang Development Board】Xun Yun's smart car

 
1. Functional Introduction
This project comes from the winter vacation training camp. It uses GD32F470ZGT6 as the core of a four-wheel drive smart car, with tracking, ultrasonic obstacle avoidance, Bluetooth remote control, OLED display of power and other information. It is powered by two 18650 lithium batteries. The electromagnetic relay and servo drive serial port pins are reserved for the completion of advanced functions in the future: aiming at the target and launching the load electromagnetic gun, etc. The front
of the car is equipped with two LED bulbs as lights for lighting.
An ultrasonic obstacle avoidance module is installed in the center of the front of the car.
Five infrared photoelectric sensors are installed on the chassis of the car to detect black and white tracking lines.
Independent motor drive, through the RZ7899 driver chip, PWM signal output is used to control the movement of a single tire.
Using a Bluetooth serial communication module, the car is remotely controlled by using an APP through interconnection with a mobile phone.
Two 18650 lithium batteries are external, with strong power.
An OLED display is used to display various information indicators of the car in real time.
A. The main control
has the following changes due to the conflict between the basic function module and the expansion interface pins:
B. Motor drive:
The N20 DC motor driven by the RZ7899 circuit in the above figure has stable performance. Its driving logic value is as follows:
Just write it in the program accordingly.
C. Power management circuit
Power input circuit:
Two 18650 lithium batteries are used as external power input power supply, with a total voltage of 7.4V, and the power input switch is controlled by the slide switch. The external power supply outputs a stable 5V voltage through a linear regulator to drive the overall circuit.
D. Infrared tracking circuit
This circuit has a total of 5 identical modules, each of which is composed of an infrared photoelectric sensor, an adjustable resistor and a green LED as the core component, which is used to identify the black guide line on the white road.
E. The buzzer circuit
uses a PNP transistor to conduct. After checking, the 5V power supply will cause the transistor to be always on, so it is solved by changing the signal circuit resistance and reducing the signal current.
F. The ADC power detection circuit
detects the voltage and provides a power signal to the OLED screen display.
G. Interfaces of each expansion module
Ultrasonic wave:
 HC-SR04 module with 4 pins is used for obstacle avoidance, 4 pins:
   Pin 1: VCC (3V~5V) Pin 2: Connected to the Trig end of the external circuit, inputting a high level of more than 10us to this pin can trigger the module to measure the distance Pin 3: Connected to the Echo end of the external circuit, when the distance measurement is over, this pin will output a high level, and the level width is the sum of the ultrasonic round trip time Pin 4: GND
   Distance = (high level time * sound speed (340M/S))/2
II. Physical display
III. Summary
The design of this car is completed. Watch the demonstration video (some program functions are not yet perfect, and I will improve them after my final exam)