Remote control car

Project Description:
This project is a control circuit developed for a JJRC remote control car.
 
Open Source License
: GPL 3.0.
 
Project Functionality:
This project is a control circuit developed for a JJRC remote control car and can be used with the remote control on my homepage. This control circuit uses the MX1919 for motor control. It can control one motor output. PWM is used to control two servo motors: one for steering and one for gear shifting. (The car in this project has high and low speeds). It also has image transmission capabilities.
 
Project Attributes:
This project is being publicly disclosed for the first time and is my original work. This project has not won any awards in other competitions.
 
Project Progress
: The PCB design is complete. This project has three PCBs.
The 3D model is complete.
The software program for remote control is complete.
The CNC bumper is complete.
Project Completion.
 
Design Principles :
This project integrates the HeZoo Air780E4G module, enabling 4G remote control. This circuit uses the ESP32C3 as the lower-level machine. The NanoPIduo2 acts as the upper-level machine and image transmission, and is responsible for communication with external devices.

This project uses four 18650 batteries connected in two parallel and two series configurations as the power source. A power management module handles charging, discharging, and voltage transformation.
An ESP32C3 microcontroller controls an MX1919 motor via PWM signals on pins IO18 and IO19 to achieve forward and reverse speed regulation. Two servo motors are connected to pins IO6 and IO11 for steering and gear shifting. An ultrasonic ranging module is connected to pins IO7 and IO10 for obstacle avoidance, and an MPU6050 gyroscope is connected via IIC for automatic angle calibration. Pins IO2 and IO3 are used as an ADC to collect and monitor battery voltage. Serial port 1 of the ESP32C3 communicates with a NanoPiduo2 microcontroller for data uploading and command sending.
This control circuit has two control modes: 4G control and ESP-Now control, selectable via a switch. In 4G control, the NanoPiduo2 receives data and uploads video; in ESP-Now control, the NanoPiduo2 is turned off, and the AIR780E stops supplying power. Data is received and uploaded via ESP32C3.

 
Software Description:
Currently, in 4G mode, there is no server available, so there is no suitable solution for the program.
The ESP-Now program
is shown in the attached physical demonstration:
Figure 1 shows the vehicle's exterior;
Figure 2 shows the vehicle's internal structure; Figure 3 shows
the upper part of the control circuit;
Figure 4 shows the lower part of the control circuit .
Design Notes:
    Due to my lack of experience, there are many shortcomings in the hardware design and circuitry, such as an unsuitable lithium battery protection chip selection leading to easy overcurrent protection, and inaccurate 3D model openings. Although it is usable, this project is generally considered a failure. Therefore, I hope this project will primarily provide a framework for improvement, and I will continue to refine it. Suggestions are welcome.