1. Custom USB Mini-B Cable
2. STM32CubeProgrammer

1. Prepare the custom cable (refer to section below)
2. Connect the custom cable to a USB-TTL serial UART adapter (do not power the adapter up yet)
3. Short these 2 pins (I used a pair of tweezers), this sets BOOT0 pin high
   
4. Connect the USB-TTL serial UART adapter to your computer
5. Launch STM32CubeProgrammer
6. Select UART connection and the correct serial port for your USB-TTL adapter
   
   1. If this is your first time programming the DFM-17, Read Unprotect (MCU) must also be checked ( factory firmware will be erased )
      
7. Click Connect
8. If connection succeeds, you can disconnect the shorted BOOT0 pins
9. You can now program the DFM-17 as you like (Read Unprotect (MCU) does not need to be checked for future re-connection attempts)

Requires soldering to PCB

Refer to DFM-17 Radiosonde - SWD Header