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taskit BLE Manufacturer Advertisement Format

Specification of the manufacturer-specific BLE broadcast packet for taskit products (BLE sensor & beacon).

  • Based on: BLE/BLE Advertisement Format
  • Source: BLE/BcastPacket-Tabelle 1.csv
  • taskit Company Identifier: 0x017B (little endian → 0x7B 0x01)

1. Packet Structure

The format uses the standard BLE advertising packet (31 bytes) consisting of two AD structures:

  1. Flags AD (3 bytes) – always 02 01 06
  2. Manufacturer Specific Data AD (variable length) with the taskit company ID
┌──────────────┬───────────────────────────────────────────────────────────┐
│  Flags AD    │              Manufacturer Specific Data (0xFF)            │
│              │                                                           │
│  02 01 06    │  [Len] FF  7B 01  [Type] [Version]  [Payload ...]         │
│  3 Bytes     │  variable length (Len = 0x1A or 0x1B, depending on type)  │
└──────────────┴───────────────────────────────────────────────────────────┘
Byte Value Meaning
1 0x02 Length of Flags AD
2 0x01 AD Type: Flags
3 0x06 LE General Discoverable + BR/EDR Not Supported
4 0x1A / 0x1B Length of Manufacturer Specific AD (26 or 27)
5 0xFF AD Type: Manufacturer Specific Data
6 0x7B Company ID Low (taskit)
7 0x01 Company ID High (taskit)
8 0x20..0x50 Type byte (frame identifier – see section 2)
9 0x15 / Version iBeacon length or protocol version
10–31 – Type-dependent payload

Bytes 1–7 are identical across all taskit variants (except byte 4: 0x1A without MAC, 0x1B with MAC).

2. Frame Types (Byte 8)

Byte 8 distinguishes between Anonymous (iBeacon-compatible) and Named (taskit's own formats):

Type Byte Category Name Byte 4 (Len) Description
0x02 Anonymous Taskit iBeacon 0x1A iBeacon-compatible (Apple layout) with taskit company ID
0x20 Named Taskit Sensor with MAC 0x1B Sensor frame, identified via MAC address
0x30 Named Taskit Sensor with RPI 0x1A Sensor frame, identified via Rotating Proximity Identifier (RPI)
0x40 Named Anchor Beacon 0x1B Positioning anchor (e.g. Beaconline)
0x50 Named Text 0x1B ASCII text message

Comparison with Apple iBeacon: bytes 6/7 = 0x4C 0x00 (Apple), byte 8 = 0x02, byte 9 = 0x15. Taskit iBeacon uses exactly the same layout, but with company ID 0x7B 0x01.

3. Complete Byte Table

The following table shows the complete layout of all 31 bytes for every frame type.

Byte Apple iBeacon Taskit iBeacon Taskit Sensor RPI Taskit Sensor MAC Anchor Beacon Text
1 0x02 0x02 0x02 0x02 0x02 0x02
2 0x01 0x01 0x01 0x01 0x01 0x01
3 0x06 0x06 0x06 0x06 0x06 0x06
4 0x1A 0x1A 0x1A 0x1B 0x1B 0x1B
5 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF
6 0x4C (Apple) 0x7B (taskit) 0x7B (taskit) 0x7B (taskit) 0x7B (taskit) 0x7B (taskit)
7 0x00 0x01 0x01 0x01 0x01 0x01
8 0x02 (Type) 0x02 (Type) 0x30 (Type) 0x20 (Type) 0x40 (Type) 0x50 (Version)
9 0x15 (Len) 0x15 (Len) Version Version Version Version
10 UUID with Type RPI / UUID Hardware ID Hardware ID Hardware ID Hardware ID
11 UUID UUID SenML Unit ID SenML Unit ID SenML Unit ID SenML Unit ID
12 UUID UUID RPI / UUID MAC MAC ASCII Text
13–17 UUID UUID RPI / UUID MAC MAC ASCII Text
18–25 UUID (up to B25) UUID (up to B25) – Name (8 B) Name ASCII Text
26–27 Major ID MajorValue – – – –
28–31 Minor (B28-29) + RSSI (B30) Minor (B28-29) + RSSI (B30) Value as 32-bit float (IEEE 754) Value as 32-bit float (IEEE 754) – –

The columns for Blue RTD / Blue Loop RX / Blue Loop TX / Blue pH-Meter are specializations of Taskit Sensor with MAC (byte 8 = 0x20) and differ only in byte 10 (hardware ID) and byte 11 (SenML unit ID).

4. Sensor Payload (Type 0x20 / 0x30)

4.1 Hardware ID (Byte 10)

Value Device
1 Blue RTD (temperature, PT100/PT1000)
3 Blue Loop RX (4–20 mA input)
4 Blue Loop TX (4–20 mA output)
5 Blue pH-Meter

4.2 SenML Unit ID (Byte 11)

Per RFC 8428 SenML Units:

Value Unit Used by
55 Cel (°C) Blue RTD
75 pH Blue pH-Meter
143 mA (milliampere) Blue Loop RX / TX

4.3 ID Field (Bytes 12–17, up to 25 where applicable)

  • Type 0x20 (sensor with MAC): 6-byte BLE MAC address in bytes 12–17, followed by an 8-byte name (bytes 18–25, ASCII)
  • Type 0x30 (sensor with RPI): Rotating Proximity Identifier in bytes 12–17 (no additional name)

4.4 Measured Value (Bytes 28–31)

The measured value is encoded as a 32-bit IEEE 754 float (bytes 28–31). The unit is determined by the SenML Unit ID (byte 11).

Example, Blue RTD at 24.7 °C:
  Value = 24.7 (IEEE 754 single)
       = 0x41 C5 99 9A
  → Bytes 28..31 = 41 C5 99 9A   (byte order per BLE spec, little endian)

5. iBeacon Payload (Type 0x02)

Identical to the Apple iBeacon layout, only with the taskit company ID:

Byte Field Size
8 iBeacon Type 0x02
9 iBeacon Length 0x15 (= 21)
10–25 UUID (or RPI) 16 bytes
26–27 Major / MajorValue 2 bytes
28–29 Minor / MinorValue 2 bytes
30 RSSI (TX power @ 1 m) 1 byte (signed)

See also: BLE/BLE Advertisement Format#5.1 iBeacon (Apple)

6. Supplementary Definitions (from CSV)

These fields are documented separately in the CSV and relate to taskit's own frame extensions:

6.1 MsgType

Data format of payload bytes 20 to 31 — see the "MsgType" table for details.

→ This byte defines the format of the following payload data.

6.2 BroadcastTime

Bit 7-4: BroadcastInterval   (see "BcastIDs" table for details)
Bit 3-0: BroadcastNumber     (continuously incrementing counter)

→ Allows the receiver to detect packet loss and determine the transmit interval.

6.3 Serialnr

taskit-unique serial number in little endian.

6.4 Daten (Data)

Format per MsgType (see 6.1).

These fields supplement the table in section 3; their exact byte position within the MsgType frame is documented in the "MsgType" and "BcastIDs" tables.

7. Complete Example Packet – Blue RTD (24.7 °C)

Advertising Data (31 bytes):

  02 01 06                              Flags: General Discoverable, BLE only
  1B FF                                 Length=27, Manufacturer Specific Data
       7B 01                            Company ID: taskit GmbH (0x017B, LE)
       20                               Type: Taskit Sensor with MAC
       01                               Version
       01                               Hardware ID: 1 = Blue RTD
       37                               SenML Unit ID: 55 = Cel (°C)
       AA BB CC DD EE FF                MAC address (6 B)
       'B' 'R' 'T' 'D' '0' '0' '0' '1'  Name (8 B, ASCII)
       -- --                            (bytes 26-27 unused)
       41 C5 99 9A                      Value = 24.7 (IEEE 754 single)

8. Complete Example Packet – Taskit iBeacon

Advertising Data (31 bytes):

  02 01 06                              Flags
  1A FF                                 Length=26, Manufacturer Specific Data
       7B 01                            Company ID: taskit GmbH
       02 15                            iBeacon Type / Length
       F7 82 6D A6 4F A2 4E 98          UUID (16 bytes)
       80 24 BC 5B 71 E0 89 3E
       00 01                            Major  = 1
       00 2A                            Minor  = 42
       C5                               RSSI   = −59 dBm @ 1 m

9. Version History

Version Date Change
v1.0 2026-05-10 Initial specification (draft, differs from implementation)
v2.0 2026-05-18 Complete revision based on BLE/BcastPacket-Tabelle 1.csv