Programming sniffer firmware using nrfutil device

To program your DK or dongle with the sniffer firmware using nRF Util's device command, complete the following steps:

Connect the DK or dongle to the computer.
Locate the firmware file for your DK or dongle. See the table above.
Install nRF Util's device command:
```
nrfutil install device
```
Find your sniffer device using the following command:
```
nrfutil device list
```
This command will list the DKs and dongles connected to your computer together with their serial numbers. For example:
```
1234567890
product         J-Link
board version   PCA10056
ports           COM13, vcom: 0
                COM12, vcom: 1
traits          devkit, jlink, seggerUsb, serialPorts, usb

A1234B5678C9
product         nRF52 RSSI Dongle
ports           COM11
traits          nordicDfu, nordicUsb, serialPorts, usb

Found 2 supported devices
```
For a development kit, the serial number is made of digits (for example, 1234567890), while for the nRF52 Dongle, it is made of 12 characters, both digits and letters (for example, A1234B5678C9).
Program the firmware file using device, replacing <serial_number> and <file_name> with the serial number of your device and the firmware file name, respectively:
```
nrfutil device program --serial-number <serial_number> --firmware <file_name>
```
For example:
- The following command would install the sniffer_nrf52840dk_nrf52840_4.1.1.hex file to an nRF52840 DK with the serial number 1234567890:
```
nrfutil device program --serial-number 1234567890 --firmware sniffer_nrf52840dk_nrf52840_4.1.1.hex
```
- The following command would install the sniffer_nrf52840dongle_nrf52840_4.1.1.zip file to an nRF52840 Dongle with the serial number A1234B5678C9:
```
nrfutil device program --serial-number A1234B5678C9 --firmware sniffer_nrf52840dongle_nrf52840_4.1.1.zip
```