VictronBLE/examples/NativeDecode/README.md

NativeDecode — decode an advertisement on your PC

Decodes one Victron "Instant Readout" advertisement on the host. No board, no BLE stack, no PlatformIO — just a C compiler. The library's core (src/victronble_core.c) is plain C99 with no dependencies, so the same decoder that runs on an ESP32, an nRF52 or under Zephyr also runs here.

Handy for:

• checking an advertisement key before you flash anything
• decoding a capture from nRF Connect, btmon or a sniffer
• seeing the record layout and which fields your device actually sends

Build and run

make
./nativedecode

With no arguments it decodes a built-in sample advert (a SmartSolar MPPT in bulk charge, taken from tests/vectors/):

advert           31 bytes
device type      solar charger (0x01)
model id         0xa060
nonce            4660 (0x1234)
fields:
  state            bulk (error 0)
  battery          13.24 V
  current          5.4 A
  pv power         340 W
  yield today      1200 Wh
  load current     n/a

Your own capture

./nativedecode <advert-hex> <key-hex>

advert-hex is the manufacturer-specific data starting at the company ID (e1 02 ...), exactly as a sniffer reports it. Separators are ignored, so e1:02:10… and e10210… both work. key-hex is the 32-character advertisement key from VictronConnect → device → gear icon → Product info → Instant readout via Bluetooth.

./nativedecode "e1021089a30002efbe0d4108532f0d44a51c62a051e97c1fae2fe9e82a0e15" \
               0df4d0395b7d5d4f5a0d0af52e1b4c1e

Reading the output

n/a means the device did not send that field — the core returns NAN for absent floats and 0xFFFF for an unavailable time-to-go, and this example renders both as n/a. An MPPT with no load output always shows load current n/a; that is not a fault.

Three failure messages are worth telling apart:

Message	Meaning
not a Victron product advertisement	wrong company ID, or not a product record — you captured something else
key check failed	the advert is Victron's, but this key belongs to a different device
decode failed: unsupported type	a real Victron record the library has no decoder for yet (e.g. GX devices)

Which API this shows

victronble_parse_key()        /* 32 hex chars -> 16 bytes           */
victronble_is_product_adv()   /* cheap pre-filter, no crypto        */
victronble_key_matches()      /* key-check byte, still no crypto    */
victronble_decode()           /* decrypt + parse into a record      */
victronble_strerror()
victronble_device_type_str()
victronble_state_str()

That is the whole portable core. See include/victronble.h for the record structures, and samples/observer/ for the same printing logic driven by a live BLE scan under Zephyr.