CH340K USB to Serial Port Mini Board

The reason for making this
was that the USB-to-serial adapter I bought before was of very poor quality. It produced severe garbled characters at high baud rates, and the crystal oscillator was severely oxidized. The large male USB connector took up a lot of space, and the DuPont wires were generally short, making it unsuitable for desktop computers. Furthermore, the female DuPont wire connectors became loose after repeated plugging and unplugging, making debugging very inconvenient. In addition, after the CH340 driver was upgraded, the cheap, high-end chip became unusable. Based on the CH340K, I made this USB-to-serial adapter myself. The external BOM is very small, requiring only two 0.1uf decoupling capacitors. Four connection methods were used, making it relatively robust! Furthermore, the Type-C connection is very flexible and common!
The actual device
is connected via an XH2.54 over-the-air cable, which is very secure and stable
at a baud rate of 921600. Communication with the host computer is very stable and there is no garbled text.
Full demonstration video:
[DIY CH340K USB to Serial Port Module] https://www.bilibili.com/video/BV1ru3aejESc/?share_source=copy_web&vd_source=72c0f3703951116e387aee15195b7689
Actual use
has been verified through board testing. Thanks to JLCPCB for providing the platform for free; I benefited greatly. Using my USB HID debugging tool at a baud rate of 921600, it is very stable! Going higher is not very meaningful, as some domestic serial port assistants do not provide such a high baud rate drop-down list option.