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BeaconLine Advertisement in CSV Format

BLE advertisements observed by the Bline anchor are output as one line per reception over TCP port 4000 / MQTT / NATS / REST. The line is a flat comma-separated list with a fixed field order — one of the fields contains the complete raw BLE data as a hex string, decoded according to BLE/taskit BLE Manufacturer Advertisement.

1. Line Structure

<timestamp_ms>,<anchor>,<mac>,<rssi>,<conn>,<adv_hex>,<node_name>
# Field Type Unit / Values Description
1 timestamp_ms uint64 Unix ms (UTC) Reception timestamp at the anchor — milliseconds since epoch.
2 anchor string bline-<SN>-<port> Identifier of the Bline anchor that observed the packet. SN = serial number, port = HCI index.
3 mac string aabbccddeeff BLE source address of the sender (public or random, possibly RPI) — without colons, 12 hex characters in a row.
4 rssi int8 dBm Received signal strength (typ. −30 … −100).
5 conn char C / N C = Connectable advertisement, N = Non-connectable.
6 adv_hex hex string 0…62 hex characters (≤ 31 bytes) Complete advertising PDU as lowercase hex — see BLE/taskit BLE Manufacturer Advertisement.
7 node_name string UTF-8 Node name (complete local name from scan response, or assigned via configuration).

Notes - Separator is , (comma). Fields themselves contain no commas; adv_hex is guaranteed hex-only, node_name is taskit-internal and comma-free. - Line ending is \n (LF). No header line, no quoting. - Multiple anchors seeing the same packet → multiple lines with identical mac + adv_hex, but different anchor, rssi, and possibly timestamp_ms.

2. Example Line

1779364221617,bline-80346594359-01,404cca5bbf1e,-80,C,0201061bff7b0120000c8e404cca5bbf1e335f676173330000000000208044,taskit_m2go.Mems
Field Value Meaning
timestamp_ms 1779364221617 2026-05-22 11:50:21.617 UTC
anchor bline-80346594359-01 Bline anchor SN 80346594359, HCI index 01
mac 404cca5bbf1e BLE address of the sensor
rssi -80 −80 dBm (medium distance)
conn C Connectable
adv_hex 0201061bff7b0120000c8e404cca5bbf1e335f676173330000000000208044 31-byte advertising payload
node_name taskit_m2go.Mems M2Go node with MEMS sensor

3. Decoding adv_hex (Example)

Applying the table from BLE/taskit BLE Manufacturer Advertisement to the 31 bytes:

Byte Hex Section Meaning
1–3 02 01 06 Flags AD Length 2, type 0x01 (flags), value 0x06 = LE General Discoverable + BR/EDR Not Supported
4 1b MSD AD Length = 27 bytes (sensor with MAC)
5 ff MSD AD AD type Manufacturer Specific Data
6–7 7b 01 MSD AD Company ID 0x017B (taskit, little endian)
8 20 Type byte 0x20 = Taskit Sensor with MAC
9 00 Version Protocol version 0
10 0c Hardware ID 12 — taskit hardware (here, the M2Go's MEMS sensor)
11 8e SenML Unit ID 142 — manufacturer-specific unit
12–17 40 4c ca 5b bf 1e MAC 404cca5bbf1e (identical to field 3)
18–27 33 5f 67 61 73 33 00 00 00 00 00 Name (ASCII, zero-padded) "3_gas3"
28–31 00 20 80 44 Value IEEE 754 float (LE) → 1024.25

Float endianness: bytes 28–31 = 00 20 80 44 are read as little endian → 0x44802000 → 1024.25. A big-endian interpretation 0x00208044 would produce a subnormal value (~3·10⁻³⁹) and is therefore ruled out.

4. Parser Sketch (Pseudo)

def parse_line(line: str) -> dict:
    ts, anchor, mac, rssi, conn, adv, name = line.rstrip("\n").split(",", 6)
    raw = bytes.fromhex(adv)
    return {
        "ts_ms":   int(ts),
        "anchor":  anchor,
        "mac":     mac,
        "rssi":    int(rssi),
        "conn":    conn == "C",
        "type":    raw[7],          # 0x02 / 0x20 / 0x30 / 0x40 / 0x50
        "version": raw[8],
        "hw_id":   raw[9],
        "unit_id": raw[10],
        "value":   struct.unpack("<f", raw[27:31])[0],   # LE float
        "name":    name,
    }

split(",", 6) is important: it ensures any stray delimiter characters end up in the last field and don't break parsing, even if node_name should ever contain a comma.

5. Special Cases

Situation Effect in CSV
Sender without scan response node_name is empty (line ends with ,).
RPI frame (Type = 0x30) mac contains the random address of the current interval; the physical MAC cannot be derived.
Anchor beacon (Type = 0x40) node_name contains the anchor name; the Value field carries no sensor measurement.
Text frame (Type = 0x50) Bytes 12–31 contain ASCII; the float interpretation does not apply.
Apple iBeacon-compatible (Type = 0x02) Bytes 26–31 follow the Apple layout (major / minor / RSSI calibration).