Bluetooth GATT Characteristic Reference

Alert Level (0x2A06)

org.bluetooth.characteristic.alert_level

The value of the characteristic shall be an unsigned 8 bit integer that has a fixed point exponent of 0. The Alert Level characteristic defines the level of alert, and is one of the following three values:

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	Alert Level
UUID	0x2A06
Type	org.bluetooth.characteristic.alert_level
XML Root	Characteristic
Source File	org.bluetooth.characteristic.alert_level.xml
Field Count	1

Field Specification

Parsed field definitions from the source XML value structure.

Field	Requirement	Format	Unit	Exponent	Notes
Alert Level	Mandatory	uint8	-	-	-

Byte Layout and Decode

Payload length is 1 bytes.

function decodePayload(dataView, offset = 0) {
  const alert_level = dataView.getUint8(offset + 0);
  return { alert_level };
}

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 Alert Level in Bluetooth GATT?

Alert Level is defined as a Bluetooth GATT characteristic entry with type org.bluetooth.characteristic.alert_level and UUID 0x2A06.

What UUID identifies Alert Level?

The UUID for Alert Level is 0x2A06.

How should I parse Alert Level?