nRF52840 sample

First of all you must install the probe-run utility.

cargo install probe-run

Add the cortex-m4 target.

rustup target add thumbv7em-none-eabihf

Create the configuration file .cargo/config.toml. The content of the file is the following:

[target.'cfg(all(target_arch = "arm", target_os = "none"))']
runner = "probe-run --chip nRF52840_xxAA  --defmt"
rustflags = [
  "-C", "link-arg=-Tlink.x",
  "-C", "link-arg=-Tdefmt.x",
]

[build]
target = "thumbv7em-none-eabihf"