Keyboard firmware for arisu style keyboard handwired using cheap STM32F401.
The firmware is keyberon.
curl https://sh.rustup.rs -sSf | sh
rustup target add thumbv7em-none-eabihf
rustup component add llvm-tools-preview
cargo install cargo-binutils
cargo objcopy --bin keyberon-f4 --release -- -O binary keyberon.bin
Press boot + restart to get into dfu mode.
dfu-util -d 0483:df11 -a 0 --dfuse-address 0x08000000 -D keyberon.bin