ST-Link V2-1 with touch buttons to swap CLK and DIO

An ST-Link V2-1 designed based on ST's official schematics and schematics circulated on the Internet, uses a USB-C interface, and adds a pin swap function through touch button control of analog switches, which can swap SWCLK and SWDIO , as well as the TXD and RXD of the serial port, there are LEDs at the corresponding positions to indicate the switching status, and the switching status is self-locking.

1. The design of this ST-Link has been initially verified and is now released to share with everyone. However, please note that this is designed using Altium Designer . Only the AD design file is provided in the attachment, which contains Gerber files that can be used directly for proofing. , BOM and other support are not provided.

2. The firmware of ST-Link can be obtained in this application sharing . The firmware should use STLinkV2.J28.M18_firmware.zip in the application sharing  . The burning of the firmware is also described in detail.

 PCB design file 3D preview

It is slightly different from the actual picture. After verification, some errors have been corrected and some unnecessary resistors and capacitors have been removed.

Schematic preview

Precautions:

1. The SWDIO and SWCLK of the chip are only connected to the SBU1 and SBU2 of USB-C. If you don't have the appropriate adapter, you can only download via flying cable.

2. This design is the ST-Link V2-1 version, which only supports STM32 debugging, with virtual serial port and virtual U disk download. Use ST-LinkUpgrade to update the firmware and switch between versions with and without U disk download.

3. Because the firmware of ST-Link V2-1 is 128KB, the MCU must also use a 128KB Flash model; you can use CKS32F103CBT6 and FCM32F103CBT6 for production. Do not try to use GD32 .