Bluetooth GATT Descriptor Reference
Number of Digitals (0x2909)
The Characteristic Number of Digitals descriptor is used for defining the number of digitals in a characteristic.
Quick Summary
Payload length is 1 bytes. 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 | Number of Digitals |
| UUID | 0x2909 |
| Type | org.bluetooth.descriptor.number_of_digitals |
| XML Root | Descriptor |
| Source File | org.bluetooth.descriptor.number_of_digitals.xml |
| Field Count | 1 |
Field Specification
Parsed field definitions from the source XML value structure.
| Field | Requirement | Format | Unit | Exponent | Notes |
|---|---|---|---|---|---|
| No of Digitals | Mandatory | uint8 | - | - | - |
Byte Layout and Decode
Payload length is 1 bytes.
function decodePayload(dataView, offset = 0) {
const no_of_digitals = dataView.getUint8(offset + 0);
return { no_of_digitals };
}Use Cases and Integration Notes
Descriptor Validation
Verify descriptor presence and format during integration and interoperability testing.
Client Configuration
Use descriptor semantics to configure notifications, indications, or presentation metadata.
Debug Diagnostics
Capture descriptor values alongside characteristic data for deeper BLE troubleshooting.
Implementation Checklist
- Read descriptor metadata after characteristic discovery to confirm behavior contracts.
- Respect descriptor read/write requirements before ATT operations.
- Document descriptor values in exported BLE session logs for reproducibility.
- Keep descriptor handling aligned with Bluetooth SIG format definitions.
FAQ
What is Number of Digitals in Bluetooth GATT?
Number of Digitals is defined as a Bluetooth GATT descriptor entry with type org.bluetooth.descriptor.number_of_digitals and UUID 0x2909.
What UUID identifies Number of Digitals?
The UUID for Number of Digitals is 0x2909.
How should I parse Number of Digitals?
Payload length is 1 bytes.
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.