Bluetooth GATT Characteristic Reference
Temperature Measurement (0x2A1C)
The flags is the first field sent followed by the Temperature Measurement Value.
Quick Summary
Payload length is profile-defined or variable based on field formats. This page is generated from official GATT XML and presented as implementation-ready guidance.
At a Glance
Key reference details for BLE implementation, interoperability testing, and AI-assisted troubleshooting.
| Property | Value |
|---|---|
| Name | Temperature Measurement |
| UUID | 0x2A1C |
| Type | org.bluetooth.characteristic.temperature_measurement |
| XML Root | Characteristic |
| Source File | org.bluetooth.characteristic.temperature_measurement.xml |
| Field Count | 5 |
Field Specification
Parsed field definitions from the source XML value structure.
| Field | Requirement | Format | Unit | Exponent | Notes |
|---|---|---|---|---|---|
| Flags | Mandatory | 8bit | - | - | - |
| Temperature Measurement Value (Celsius) | C1 | FLOAT | org.bluetooth.unit.thermodynamic_temperature.degree_celsius | - | This field is only included if the flags bit 0 is 0. |
| Temperature Measurement Value (Fahrenheit) | C2 | FLOAT | org.bluetooth.unit.thermodynamic_temperature.degree_fahrenheit | - | This field is only included if the flags bit 0 is 1. |
| Time Stamp | C3 | N/A | - | - | If the flags bit 1 is 1 this field is included. If it is 0, this field is not included |
| Temperature Type | C4 | N/A | - | - | If the flags bit 2 is set to 1 this field is included. If it is 0, this field is not included |
Bit Map
Bit-level enumerations extracted from the XML BitField definition.
| Field | Bit | Size | Name | 0 Means | 1 Means |
|---|---|---|---|---|---|
| Flags | 0 | 1 | Temperature Units Flag | Temperature Measurement Value in units of Celsius | Temperature Measurement Value in units of Fahrenheit |
| Flags | 1 | 1 | Time Stamp Flag | Time Stamp field not present | Time Stamp field present |
| Flags | 2 | 1 | Temperature Type Flag | Temperature Type field not present | Temperature Type field present |
Byte Layout and Decode
Payload length is profile-defined or variable based on field formats.
function decodePayload(dataView, offset = 0) {
// Parse flags (8bit) according to Bluetooth format rules.
// Parse temperature_measurement_value_celsius (FLOAT) according to Bluetooth format rules.
// Parse temperature_measurement_value_fahrenheit (FLOAT) according to Bluetooth format rules.
// Parse time_stamp (N/A) according to Bluetooth format rules.
// Parse temperature_type (N/A) according to Bluetooth format rules.
return { flags, temperature_measurement_value_celsius, temperature_measurement_value_fahrenheit, time_stamp, temperature_type };
}Use Cases and Integration Notes
BLE Telemetry
Map characteristic values into dashboards and alerts for device observability.
Firmware Regression
Compare decoded fields across builds to detect protocol or scaling changes.
App Integration
Build stable parsing paths that convert raw payloads into typed app models.
Implementation Checklist
- Validate payload length and mandatory fields before decode.
- Decode with Bluetooth-specified signedness, unit, and exponent handling.
- Convert units at presentation boundaries to avoid drift in business logic.
- Persist raw packets and decoded values for reproducible troubleshooting.
FAQ
What is Temperature Measurement in Bluetooth GATT?
Temperature Measurement is defined as a Bluetooth GATT characteristic entry with type org.bluetooth.characteristic.temperature_measurement and UUID 0x2A1C.
What UUID identifies Temperature Measurement?
The UUID for Temperature Measurement is 0x2A1C.
How should I parse Temperature Measurement?
Payload length is profile-defined or variable based on field formats.
Where does this definition come from?
This page is generated from the Bluetooth SIG mirror XML in the oesmith/gatt-xml repository.
How does this page support BLE implementation?
The page combines structured tables, practical Q&A, and JSON-LD metadata to help teams validate integrations and troubleshoot consistently.