【LiChuang Development Board】A vehicle with Bluetooth function

## Project Description

###### This project is based on the Bluetooth module HC-05, the motor driver chip MX1508 and the LiChuang Liangshanpai development board, and is a Bluetooth remote control car powered by a 7.4V lithium battery. It can realize functions such as USB 5V charging for 7.4V lithium battery, and mobile phone APP control of car lights and travel direction.

## Schematic Design Description

###### The LiChuang Liangshanpai development board is a domestically produced open source development board based on GD32F450ZGT6, with rich resource interfaces (as shown in the figure), and is equipped with complete supporting video tutorials, document tutorials, and experimental cases.

![image.png]
###### In this project, 2X20P motherboard is used to connect Liangshanpai and the functional baseboard;

###### Because the main power supply uses 7.4V, which is higher than the power supply voltage required by the development board, AMS1117-5.0V is used to reduce the power supply voltage from 7.4V to 5V:

![image.png]
######

###### In order to charge the on-board lithium battery, INJOINIC's IP2325 chip is used. IP2325 is a boost charging management IC that supports dual-series lithium batteries/lithium-ion batteries. Integrated power MOS and synchronous switch architecture require only a few peripheral devices when applied, and effectively reduce the size of the overall solution to reduce BOM costs, making it very suitable for use in this project.

![image.png]
###### The motor driver chip uses MX1508. This chip integrates two channels of H-bridge driver circuits designed with N-channel and P-channel power MOSFETs. It has a wide operating voltage range (from 2V to 9.6V), and the maximum continuous output current of the drive motor reaches 0.8A, the maximum peak output current reaches 1.5A, and only a few peripheral devices are required:

![image.png]
## PCB Design Description

###### This project uses many chips and modules that do not require complex peripheral devices, which greatly reduces the difficulty of PCB design and wiring; it should be noted that the motor part needs to pass a relatively high current, and the trace width should be increased to prevent heating.

###### The connection part with the Bluetooth module needs to be paid attention to. Because the serial port connection is used, the TX and RX of Liangshan School need to be cross-connected to the RX and TX of the Bluetooth module. At the same time, the baud rate of HC-05 needs to be paid attention to, which is generally 9600 or 38400.

## Software Description

###### Liangshanpai development board is a development board based on GD32F450ZGT6. There are many detailed code tutorials on its official website and official account, which are very helpful for beginners to get started and complete this project.

###### Write the main user code in main. You need to initialize the required functions first, and then use the while(1) function to loop infinitely to read whether the Bluetooth module has received data:

```
  LED_Init();
  Motor_Init();
  PWM_Init(200,100);
  Serial_Init(9600U);

    while(1)
{

```

###### The mobile APP uses Arduino bluetooth controller, which is a multi-functional Bluetooth debugging APP that can be downloaded for free on Google Play. It has powerful functions and no ads. In this project, define the up, down, left, and right buttons as ABCD for control:

![image.png]
## Physical display description

###### Front and back of the 7.4V battery panel:

![image.png]
###### Overall front:

![image.png]
## Precautions

###### This project uses a 7.4V lithium battery pack. A lithium battery protection board is designed and installed on the battery pack board. It can detect short circuit and overcurrent output during normal operation; but it is still necessary to prevent this from happening during operation. Before each start, carefully check the load connection to avoid accidents.

## Demo Video

###### Uploaded to Attachment

## Future Outlook

###### There are so many things to do at school. I am too busy, too busy, too busy, too busy. Many of the functions I hope for have not been added in time. I will add more functions later. I look forward to it.

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