badapple.f1.mp4
The corne v3 uses only one of the TR(R)S pins, but this firmware needs both data pins to use a uart connection (I don't feel like doing what QMK does), you'll need to add a bodge wire between P1.04 and the unused pin of the TRRS jack (it's the one not part of the group of three pins in a line)
It's possible to create uf2 files for rust firmware by using the following memory.x:
MEMORY
{
/* NOTE 1 K = 1 KiBi = 1024 bytes */
FLASH : ORIGIN = 0x00026000, LENGTH = 868K
RAM : ORIGIN = 0x20020000, LENGTH = 128K
}
You can then use my fork of elf2uf2-rs to convert to uf2: https://github.com/simmsb/elf2uf2-rs
elf2uf2-rs target/thumbv7em-none-eabihf/release/left left.uf2
Make sure the softdevice hasn't been wiped from the nice!nano (you can just reflash it if it has)