Multifunctional debugger-Share

describe:

1. Use SL2.1A for USB expansion from one to four. The peripheral circuit of this chip is simple and the chip pin wiring is convenient.

2. dap-link: Using STM32F103C8T6 as the main control can download and simulate all cortexM0, cortexM3, cortexM4, and cortexM7, and has a virtual serial port.

3. Use an LDO to power the dap-link independently, which is more stable.

3. Two-way USB to serial port: Use HT42B534 as the conversion chip. This chip can control the serial port level (5V/3.3V) by controlling VDDIO, and has a built-in crystal oscillator, which is more convenient than the traditional CH340G.

4. Reserve a USB female socket for emergencies.

5. Using a four-pin micro USB socket is more stable.

6. It is more convenient to debug with 5V, 3.3V and GND drawn out from the board.

PS: Prototype has been verified (the DAPlink design refers to Jixiaoxin’s DAPlink https://www.jixin.pro/bbs/topic/4187)~~~~

Unsoldered front

Unsoldered reverse side

As shown in the figure below, both the dap-link and the two serial ports can be powered on and off through the onboard toggle switch, making the control more convenient.

Welding completed front

Welding completed reverse side

The test description document and the source code file of dap-link will be provided in the attachment.