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Why Use This Library?

The Problem with Raw BLE Data

When working with Bluetooth Low Energy (BLE) devices, you typically encounter raw binary data that needs to be interpreted according to Bluetooth SIG specifications. This creates several challenges:

Challenge 1: Complex Data Formats

# Raw BLE characteristic data
raw_data = bytearray([0x64, 0x09])  # What does this mean? 🤔

Without proper interpretation, this is just bytes. According to Bluetooth SIG specifications for the Temperature characteristic (0x2A6E), this represents 24.36°C (2404 * 0.01).

Challenge 2: UUID Management

# UUIDs are cryptic
uuid = "0000180f-0000-1000-8000-00805f9b34fb"  # What service is this?

These 128-bit UUIDs need to be mapped to human-readable names like "Battery Service" based on the official Bluetooth SIG registry.

Challenge 3: Standards Compliance

Each characteristic has specific parsing rules:

  • Different byte orders (little-endian vs big-endian)
  • Varying data types (uint8, sint16, SFLOAT, etc.)
  • Special sentinel values (0xFFFF meaning "unknown")
  • Conditional fields based on flags
  • Unit conversions and scaling factors

The Solution: bluetooth-sig

This library handles all the complexity for you:

✅ Automatic Standards Interpretation

from bluetooth_sig import BluetoothSIGTranslator

translator = BluetoothSIGTranslator()

# Parse according to official specifications
temp_data = translator.parse_characteristic("2A6E", bytearray([0x64, 0x09]))
print(f"Temperature: {temp_data.value}°C")  # Temperature: 24.36°C

✅ UUID Resolution

# Resolve UUIDs to names
service_info = translator.get_sig_info_by_uuid("180F")
print(service_info.name)  # "Battery Service"

# Reverse lookup
battery_service = translator.get_sig_info_by_name("Battery Service")
print(battery_service.uuid)  # "180F"

✅ Type-Safe Data Structures

# Get structured data, not raw bytes
battery_data = translator.parse_characteristic("2A19", bytearray([85]))

# battery_data is a typed dataclass with validation
assert battery_data.value == 85
assert 0 <= battery_data.value <= 100  # Automatically validated

When Should You Use This Library?

✅ Perfect For

  • Application Developers: Building apps that need to display BLE sensor data
  • IoT Projects: Reading data from Bluetooth sensors and devices
  • Testing & Validation: Verifying BLE device implementations
  • Protocol Implementation: Building BLE client applications
  • Research & Analysis: Analysing BLE device behaviour
  • Custom Protocols: Supports custom GATT characteristics via extension API

❌ Not Designed For

  • BLE Connection Management: Use bleak, simplepyble, or similar libraries for actual device connections
  • Firmware Development: This is a client-side library, not for embedded devices
  • Real-time Streaming: Optimized for parsing, not high-frequency streaming

Key Differentiators

1. Standards-First Approach

Built directly from official Bluetooth SIG specifications. Every characteristic parser is validated against the official documentation.

2. Framework Agnostic

Works with any BLE connection library:

# Works with bleak
from bleak import BleakClient
raw_data = await client.read_gatt_char(uuid)
parsed = translator.parse_characteristic(uuid, raw_data)

# Works with simplepyble
from simplepyble import Peripheral
raw_data = peripheral.read(service_uuid, char_uuid)
parsed = translator.parse_characteristic(char_uuid, raw_data)

# Works with ANY BLE library

3. Type Safety & Validation

from bluetooth_sig.gatt.characteristics import BatteryLevelCharacteristic

char = BatteryLevelCharacteristic()

# Automatic validation
try:
    char.decode_value(bytearray([150]))  # Invalid: > 100
except ValueError as e:
    print(e)  # "Battery level must be 0-100%, got 150%"

4. Comprehensive Coverage

Support for 70+ characteristics across multiple service categories:

  • Battery Service
  • Environmental Sensing (temperature, humidity, pressure, air quality)
  • Health Monitoring (heart rate, blood pressure, glucose)
  • Fitness Tracking (running, cycling speed/cadence/power)
  • Device Information
  • And many more...

Comparison with DIY Parsing

Feature bluetooth-sig DIY Manual Parsing
Standards Compliance ✅ Official specs ❌ Manual implementation
Type Safety ✅ Full typing ❌ Raw bytes
UUID Resolution ✅ Automatic ❌ Manual mapping
BLE Library Support ✅ Any library ✅ Any library
Validation ✅ Built-in ❌ Manual
Maintenance ✅ SIG registry updates ❌ You maintain
Custom Characteristics ✅ Extension API ✅ You implement everything

Real-World Example

Without bluetooth-sig

# Manual parsing (error-prone)
def parse_battery_level(data: bytes) -> int:
    if len(data) != 1:
        raise ValueError("Invalid length")
    value = data[0]
    if value > 100:
        raise ValueError("Invalid range")
    return value

# Manual UUID mapping
UUID_MAP = {
    "2A19": "Battery Level",
    "180F": "Battery Service",
    # ... hundreds more
}

With bluetooth-sig

from bluetooth_sig import BluetoothSIGTranslator

translator = BluetoothSIGTranslator()

# One line, standards-compliant, type-safe
result = translator.parse_characteristic("2A19", data)

Next Steps