https://github.com/jamesmunns/ergot/blob/main/demos/nrf52840-null/src/main.rs is what the "local only" example looks like

edit, size with +nightly:

```
   text	   data	    bss	    dec	    hex	filename
  12432	     80	   5624	  18136	   46d8	nrf52840-null
```