What Problems It Solves

This library addresses specific pain points when working with Bluetooth Low Energy (BLE) devices and Bluetooth SIG specifications.

Problem 1: Standards Interpretation Complexity

The Challenge (Standards Interpretation)

Bluetooth SIG specifications are detailed technical documents that define how to encode/decode data for each characteristic. Implementing these correctly requires:

• Understanding binary data formats (uint8, sint16, IEEE-11073 SFLOAT)
• Handling byte order (little-endian, big-endian)
• Implementing conditional parsing based on flags
• Managing special values (0xFFFF = "unknown", NaN representations)
• Applying correct unit conversions

Example: Temperature Characteristic (0x2A6E)

Specification Requirements:

• 2 bytes (sint16)
• Little-endian byte order
• Resolution: 0.01°C
• Special value: 0x8000 (-32768) = "Not Available"
• Valid range: -273.15°C to +327.67°C

Manual Implementation:

def parse_temperature(data: bytes) -> float | None:
    if len(data) != 2:
        raise ValueError("Temperature requires 2 bytes")

    raw_value = int.from_bytes(data, byteorder='little', signed=True)

    if raw_value == -32768:  # 0x8000
        return None  # Not available

    if raw_value < -27315 or raw_value > 32767:
        raise ValueError("Temperature out of range")

    return raw_value * 0.01

With bluetooth-sig:

from bluetooth_sig import BluetoothSIGTranslator

translator = BluetoothSIGTranslator()
result = translator.parse_characteristic("2A6E", data)
# Handles all validation, conversion, and edge cases automatically

✅ What We Solve (Standards Interpretation)

• Automatic standards compliance - All 70+ characteristics follow official specs
• Unit conversion handling - Correct scaling factors applied automatically
• Edge case management - Special values and sentinels handled correctly
• Validation - Input data validated before parsing
• Type safety - Structured data returned, not raw bytes

---

Problem 2: UUID Management & Resolution

The Challenge (UUID Management)

Bluetooth uses UUIDs to identify services and characteristics:

• Short form: 180F (16-bit)
• Long form: 0000180f-0000-1000-8000-00805f9b34fb (128-bit)

Both represent "Battery Service", but you need to:

1. Maintain a mapping of UUIDs to names
2. Handle both short and long forms
3. Support reverse lookup (name → UUID)
4. Keep up with Bluetooth SIG registry updates

Manual Approach

# Maintaining a UUID registry manually
SERVICE_UUIDS = {
    "180F": "Battery Service",
    "180A": "Device Information",
    "1809": "Health Thermometer",
    # ... hundreds more
}

CHARACTERISTIC_UUIDS = {
    "2A19": "Battery Level",
    "2A6E": "Temperature",
    "2A6F": "Humidity",
    # ... hundreds more
}

# Handling lookups
def resolve_by_name(uuid: str) -> str:
    # Short form?
    if len(uuid) == 4:
        return SERVICE_UUIDS.get(uuid) or CHARACTERISTIC_UUIDS.get(uuid)
    # Long form?
    elif len(uuid) == 36:
        short = uuid[4:8]
        return SERVICE_UUIDS.get(short) or CHARACTERISTIC_UUIDS.get(short)
    return "Unknown"

✅ What We Solve (UUID Management)

from bluetooth_sig import BluetoothSIGTranslator

translator = BluetoothSIGTranslator()

# Automatic UUID resolution (short or long form)
info = translator.get_sig_info_by_uuid("180F")
info = translator.get_sig_info_by_uuid("0000180f-0000-1000-8000-00805f9b34fb")  # Same result

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

# Get full information
print(info.name)  # "Battery Service"
print(info.type)  # "service"
print(info.uuid)  # "180F"

• Official registry - Based on Bluetooth SIG YAML specifications
• Automatic updates - Registry updates via submodule
• Both directions - UUID → name and name → UUID
• Multiple formats - Handles short and long UUID forms

---

Problem 3: Type Safety & Data Validation

The Challenge (Type Safety)

Raw BLE data is just bytes. Without proper typing:

• Errors caught at runtime, not compile time
• No IDE autocomplete
• Unclear what fields are available
• Easy to make mistakes with raw bytes

Untyped Approach

# What does this return?
def parse_battery(data: bytes):
    return data[0]

# Is it a dict? A tuple? An int?
result = parse_battery(some_data)
# No type hints, no validation, no structure

✅ What We Solve (Type Safety)

from bluetooth_sig import BluetoothSIGTranslator

translator = BluetoothSIGTranslator()
result = translator.parse_characteristic("2A19", bytearray([85]))

# result is a typed dataclass
# IDE autocomplete works
# Type checkers (mypy) validate usage
print(result.value)  # 85
print(result.unit)   # "%"

# For complex characteristics
temp_result = translator.parse_characteristic("2A1C", data)
# Returns TemperatureMeasurement dataclass with:
#   - value: float
#   - unit: str
#   - timestamp: datetime | None
#   - temperature_type: str | None

• Full type hints - Every function and return type annotated
• Dataclass returns - Structured data, not dictionaries
• IDE support - Autocomplete and inline documentation
• Type checking - Works with mypy, pyright, etc.

---

Problem 4: Framework Lock-in

The Challenge (Framework Lock-in)

Many BLE libraries combine connection management with data parsing, forcing you to:

• Use their specific API
• Learn their abstractions
• Be limited to their supported platforms
• Migrate everything if you want to change BLE libraries

✅ What We Solve (Framework Lock-in)

Framework-agnostic design - Parse data from any BLE library:

from bluetooth_sig import BluetoothSIGTranslator

translator = BluetoothSIGTranslator()

# Works with bleak
from bleak import BleakClient
async with BleakClient(address) as client:
    data = await client.read_gatt_char(uuid)
    result = translator.parse_characteristic(uuid, data)

# Works with simplepyble
from simplepyble import Peripheral
peripheral = Peripheral(adapter, address)
data = peripheral.read(service_uuid, char_uuid)
result = translator.parse_characteristic(char_uuid, data)

# Works with your custom BLE implementation
data = my_custom_ble_lib.read_characteristic(uuid)
result = translator.parse_characteristic(uuid, data)

• Separation of concerns - Parsing separate from connection
• Library choice - Use any BLE connection library you prefer
• Platform flexibility - Not tied to specific OS/platform
• Testing - Easy to mock BLE interactions

---

Problem 5: Maintenance Burden

The Challenge (Maintenance Burden)

Maintaining a custom BLE parsing implementation requires:

• Monitoring Bluetooth SIG specification updates
• Adding new characteristics as they're adopted
• Fixing bugs in parsing logic
• Keeping up with new data formats
• Ensuring backwards compatibility

✅ What We Solve (Maintenance Burden)

• Centralized maintenance - One library, many users
• SIG registry updates - New characteristics added as standards evolve
• Community testing - Bugs found and fixed by multiple users
• Specification compliance - Validated against official specs
• Version management - Clear versioning and changelog

---

Problem 6: Complex Multi-Field Characteristics

The Challenge (Multi-Field Characteristics)

Many characteristics have conditional fields based on flags:

Temperature Measurement (0x2A1C):

Byte 0: Flags
  - Bit 0: Temperature unit (0=°C, 1=°F)
  - Bit 1: Timestamp present
  - Bit 2: Temperature Type present
Bytes 1-4: Temperature value (IEEE-11073 SFLOAT)
Bytes 5-11: Timestamp (if bit 1 set)
Byte 12: Temperature Type (if bit 2 set)

Manual Implementation

def parse_temp_measurement(data: bytes) -> dict:
    flags = data[0]
    offset = 1

    # Parse temperature (IEEE-11073 SFLOAT - complex format)
    temp_bytes = data[offset:offset+4]
    temp_value = parse_ieee_sfloat(temp_bytes)  # Another complex function
    offset += 4

    # Conditional fields
    timestamp = None
    if flags & 0x02:
        timestamp = parse_timestamp(data[offset:offset+7])
        offset += 7

    temp_type = None
    if flags & 0x04:
        temp_type = data[offset]

    return {
        "value": temp_value,
        "unit": "°F" if flags & 0x01 else "°C",
        "timestamp": timestamp,
        "type": temp_type
    }

✅ What We Solve (Multi-Field Characteristics)

from bluetooth_sig import BluetoothSIGTranslator

translator = BluetoothSIGTranslator()
result = translator.parse_characteristic("2A1C", data)

# Returns TemperatureMeasurement dataclass with all fields parsed
# Handles all flag combinations automatically
# Returns type-safe structured data

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Summary: Key Problems Solved

Problem	Manual Approach	bluetooth-sig Solution
Standards interpretation	Implement specs manually	Automatic, validated parsing
UUID management	Maintain mappings	Official registry with auto-resolution
Type safety	Raw bytes/dicts	Typed dataclasses
Framework lock-in	Library-specific APIs	Works with any BLE library
Maintenance	You maintain	Community maintained
Complex parsing	Custom logic for each	Built-in for 70+ characteristics
Validation	Manual checks	Automatic validation
Documentation	Write your own	Comprehensive docs

What's Next?

• What It Does NOT Solve - Understand the boundaries
• Quick Start - Start using the library
• Usage Guide - Detailed usage examples
• API Reference - Complete API documentation