TYPEC→DP+USB2/3 Expansion Adapter Board

CH32X0435-based TYPEC→DP+USB2/3 Expansion Adapter Board
I. Overview
The CH32X035 series is an industrial-grade microcontroller based on the Qingke V4C core. The CH32X035 integrates USB and PD PHYs, supporting USB Host and USB Device functions, USB PD and Type-C fast charging. It also features a built-in programmable protocol I/O controller, providing rich peripheral resources such as OPA operational amplifiers, CMP voltage comparators, USART serial ports, I2C, SPI, timers, a 12-bit ADC, and touchkeys. 
II. System Block Diagram
The CH32X035C8T6 has a very rich set of peripherals and pins, suitable for PD decoys/EDP display driver boards, etc.
However, the official example code does not provide specific communication procedures for DP ALT MODE, only voltage decoy code.
Therefore, this project will verify the feasibility of DP ALT MODE CC communication with the CH32X035C8T6.
III. Program Download Method
Due to the poor code quality, it will be open-sourced after improvement. However, the HEX file for the verification board is provided below and can be downloaded as needed.
First, download WCHISPTOOL: WCHISPTool_Setup.exe - Nanjing Qinheng Microelectronics Co., Ltd.
Then, open WCHISPSTUDIO. Select CH32X03x for the chip series, CH32X035C8T6 for the chip, USB for the download interface, and the HEX file below as the target program.
See the image below:
Next, insert the USB end of a standard USB-TYPEC cable (the more standard the better; a fast charging cable may cause download failure).
Then press and hold the download button, and insert the TYPEC cable into the verification board.
WCHISPSTUDIO should now display the following interface:
Then click "Remove Code Protection":
Then click "Download":
The program download is now complete. You will notice that CC1 and CC2 are flashing.
Note:
If both CC1 and CC2 lights on the board are flashing, it indicates that CC communication has failed and the voltage negotiation stage has not yet begun.
If one of CC1/CC2 lights is constantly on but the power light is flashing (verification board power off and restarted), it means that CC communication has successfully completed voltage negotiation but the video signal request has failed.
With CC1/CC2 constantly lit, there's a high probability that the DP signal has been successfully output, indicating that the device has entered DP signal negotiation mode.
Verified devices: Huawei Mate30 Pro/Matepad Pro/Zoom 14 2022/Dell Inspiron 5301