Logs every Victron "Instant Readout" advertisement in range. No advertisement keys and no device list required, so this is the first thing to run: it tells you what you have and what its Bluetooth address is.

The whole sample is victronble_watch_set(true) plus victronble_start() — all the output comes from the library's own log module.

Build and run

west build -p -b nrf52840dk/nrf52840 -d /tmp/vb_scan samples/scan \
    -- -DZEPHYR_EXTRA_MODULES=$PWD
west flash -d /tmp/vb_scan

Console (115200 baud):

<inf> scan: VictronBLE discovery — logging every Victron advert in range
<inf> victronble: observing (interval 96 window 48)
<inf> victronble: watch: E4:05:42:34:14:F3 (random) rssi -67 type 0x01 (solar charger) len 31 keycheck 0x0d
<inf> victronble: watch: E6:45:59:78:3C:FB (random) rssi -82 type 0x02 (battery monitor) len 31 keycheck 0x3f
<inf> scan: stats: adverts 61 queued 61 dropped 0

Each line gives you everything you need for samples/observer:

Field	Use
address + `(random)`	Victron uses random static addresses — that address type matters
`type`	which device family it is, before any decryption
`keycheck`	first byte of the advertisement key; confirms you copied the right key
`rssi`	how well you can hear it — useful for placing the node

Nothing here is decrypted. Watch mode reads only the plaintext header, which is why it works without keys.

Next step

Copy the addresses into the known_devices table in ../observer/src/main.c along with each device's key from VictronConnect (device → gear icon → Product info → Instant readout via Bluetooth), then build observer.

Notes

Unregistered devices are not deduplicated by nonce, so expect roughly one line per device per second. That is the point — it shows liveness.
prj.conf raises the scan duty cycle to 60 ms / 30 ms (BT_GAP_SCAN_FAST_*) instead of the library default 1.28 s / 11.25 ms. Discovery should be quick; observer uses the low-power default.
CONFIG_VICTRONBLE_QUEUE_DEPTH=16 because watch mode queues every advert, not just the ones from known devices. If dropped climbs on a busy site, raise it further.
adverts 0 after a minute means either nothing is in range or the device has Instant readout via Bluetooth switched off in VictronConnect.