Seriously Pro F3 from China: Fixing STM32 communication failed, wrong response, expected: 121 (0x79) received: 31 (0x1f)

Russian version

I was unable to flash Betaflight to my Seriously Pro F3 flight controller from China because of error:

STM32 communication failed, wrong response, expected: 121 (0x79) received: 31 (0x1f)

Here is how to fix it:

• Download and install STM32 Flash Loader Demonstrator
• Short BOOT pins and connect controller to USB port
• Open STM32 Flash Loader Demonstrator, choose COM-port, set Baud Rate to 256000, click Next

• Remove protection by clicking button ‘Remove Protection’

• Check the ‘Target’, it should have text similar to STM32F3

• Select ‘Download to device’, press “…” button and choose valid Betaflight or Cleanflight hex file from releases for SPRacingF3.

• Wait while flashing process completes, unshort BOOT pins, disconnect and connect the board. Now you can flash any firmware via Cleanflight configurator software