Making a bluetooth split keyboard (Part 1-a)

A bit of a followup on a previous entry, I’ve succeeded in turning a Chinese STM32F103 clone into a Black Magic Probe :

I found some instructions in blackmagic-bluepill to follow

I’ll try to summarize:

  1. wiring is important!
Wiring diagram
  1. Since the whole point of making the BMP flasher/debugger was to flash the nRFmicro, I followed the instructions on the nRFmicro repo got their supplied blackmagic binaries
  2. For some reason I had to fiddle around and hold the reset button before attaching a device (search STM32 bluepill connect under reset for more on this) , it was a hit and miss thing … (arm-none-eabi-binutils, arm-none-eabi-gcc and arm-none-eabi-gdb are installed at this point, this is the list of commands to follow:
  3. I couldn’t load .bin files so I converted the downloaded binaries to .hex files
arm-none-eabi-objcopy -I binary -O ihex blackmagic_dfu.bin blackmagic_dfu.hex
arm-none-eabi-objcopy -I binary -O ihex blackmagic.bin blackmagic.hex
target extended-remote /dev/ttyBmpGdb 
#/dev/ttyACM0 or /dev/ttyACM1 if the device rules are not installed
monitor swdp_scan
 should show the target board voltage and Something like
. Att Driver
#1      M4

 until this point I was holding the target board's reset button
 had to try multiple times to do the following step and releasing the reset
 at the same time
attach 1
load ./blackmagic_dfu.hex 0x8000000
load ./blackmagic.hex 0x8002000

Issuing lsusb yields:

So yes, I now have a fully operational blackmagic-bluepill 😀

Day 16 of my 2021’s

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