laxis96/switchalyzer

Switchalyzer

Mechanical keyboard switch force curve analyzer.

The plan is to design hardware (3D printed structure) and software (probably on STM32 and hopefully written in Zig).

Build

Requirements:

• ARM GCC toolchain: https://developer.arm.com/Tools%20and%20Software/GNU%20Toolchain
  for building libopencm3 and debugging
• Zig: https://ziglang.org/download
• OpenOCD: https://github.com/openocd-org/openocd/releases
  for flashing and debugging
• Python 3.x
  for linker script generation (from libopencm3)

libopencm3

libopencm3 must be built with GCC arm-none-eabi (though in the future it might be handled by zig cc).

https://github.com/libopencm3/libopencm3

• On Windows: https://www.msys2.org/
  • Use UCRT64 environment
  • Install make: pacman -S make
  • If python3 is missing, run via cmd as Administrator: mklink "C:\Program Files\Python311\python3.exe" "C:\Program Files\Python311\python.exe"

  • . env.sh

• make -C libopencm3 # TARGETS="stm32/f1"

switchalyzer

zig build

Flash

zig build flash

Debug

1. Install Cortex-Debug VSCode extension (https://github.com/Marus/cortex-debug)
2. Also install Cortex-Debug: Device Support Pack - STM32F1 and equivalent extensions as needed (to enable peripherals view in debug)
3. Set cortex-debug.armToolchainPath in VSCode settings.json to the bin directory of your arm-none-eabi toolchain
4. Set cortex-debug.openocdPath to openocd.exe
5. Launch the included debug configuration(s)

SWO/SWV is used for trace output, OpenOCD and Cortex-Debug will automatically configure the needed on-chip registers (TPIU, ITM, DBGMCU) to enable SWO output.

TODO try DWT and ETM tracing

References

• https://ziglang.org/documentation/master
• https://ziglang.org/documentation/master/std
• https://maldus512.medium.com/zig-bare-metal-programming-on-stm32f103-booting-up-b0ecdcf0de35
• https://github.com/rbino/zig-stm32-blink
• https://rbino.com/posts/zig-stm32-blink/
• https://ciesie.com/tags/stm32/
• https://andrewkelley.me/post/zig-stack-traces-kernel-panic-bare-bones-os.html
• https://ikrima.dev/dev-notes/zig/zig-build/