You need to use firmware files provided by nRF Util. The file must match the development kit or dongle you want to use as the sniffer device.
The files are copied to the /share/nrfutil-ble-sniffer/firmware subdirectory under the installation directory of nRF Util when you install the ble-sniffer command.
The following firmware files are available:
| Development kit/dongle | Firmware file name |
|---|---|
| nRF52840 DK (PCA10056) | sniffer_nrf52840dk_nrf52840_*.hex |
| nRF52840 Dongle (PCA10059) | sniffer_nrf52840dongle_nrf52840_*.zip (requires ZIP instead of HEX) |
| nRF52833 DK (PCA10100) | sniffer_nrf52833dk_nrf52833_*.hex |
| nRF52 DK (PCA10040) | sniffer_nrf52dk_nrf52832_*.hex |
The asterisk (*) in the file name corresponds to the firmware file version, for example v4.4.1 in sniffer_nrf52840dk_nrf52840_4.4.1.hex.