DAP42 - Single chip onboard DAPLINK solution

Reproduced from the project https://github.com/devanlai/dap42,
it uses a piece of STM32F042F6P6 as a CMSIS-DAP (a minimum of two yuan per piece with free shipping on a certain treasure).
The package is much smaller than that of CH549G. I personally don’t like the silly big black thick of WCH-LINK. chip, so I found this project.
The advantage is that if you take power from the onboard 3V3, you don’t need any external components (including resistors and capacitors). You can directly add a chip to communicate with the MCU, and the other end is directly connected to USB to achieve debugging+ This single-channel serial port communication
project is just to verify the feasibility of the debugger. In fact, it is not recommended to prototype my board, but to directly add the reference circuit to your project (I have verified that
the download speed is no different from ordinary DAPLINK, and even It's faster, but not as good as the high-speed USB DAPLINK that costs nearly 100 yuan
. There is no problem running the serial port 921600.
The TGT_TX/RX in the circuit refers to the TX/RX of the debugger itself. Remember to cross
the original project Release . It has not been updated for a long time. Attached is the latest firmware I compiled. Use the following command to burn directly from usb (you may need Zadig to install the WinUSB driver to recognize the dfu mode of the empty chip. Check your device manager for an exclamation mark)
. The firmware does not support SWO, and I don't use it, so I didn't export it. Github has supported firmware and compiled it myself
dfu-util.exe -d 1209:da42,0483:df11 -a 0 -s 0x08000000:leave -D DAP42.bin.