The softdevice blob is not distributed with this repository for licensing
reasons (even though it would be possible if my understanding is correct).

Download the
[S140 Softdevice](https://www.nordicsemi.com/Products/Development-software/s140/download)
and flash it to your chip.

_Example command to flash the softdevice_

```
probe-rs download --verify --format hex --chip nRF52840_xxAA ./s140_nrf52_7.3.0_softdevice.hex
```