JLink ARM OB simulation debugger with a width of less than 1 cm [verified]

This version of JLink ARM OB is modified based on X893/CMSIS-DAP; this version of JLink ARM OB uses STM32F072CBU6 internal oscillator, eliminating the need for an external crystal oscillator, and the PCB area is smaller. This version does not have a reserved SW download interface. It can be downloaded through the serial port. Before downloading, connect BOOT0 on the back to high (see PCB diagram for details). RXD/TXD/GND is reserved on the back for easy downloading. It is recommended to use ST’s official serial port download tool Flash Loader. Demonstrator, the firmware is on GitHub - geekchun/Jlink-OB (you can also view the attachment jlink-ob-072-cortex-m.bin). After the download is completed, BOOT0 needs to be pulled low or left floating. JLink ARM OB has updated the USB Type-C interface. The advantage is that you don’t have to worry about plugging it in backwards. The tail welding probe or 2.54 pin header can be cut off appropriately as needed.

Welding reference drawing

Jumper reference

Before applying heat shrink tubing

After applying heat shrink tube