I. Classification by technology type

1. Classic Bluetooth (Bluetooth Classic, BR/EDR)

Features: Support high-bandwidth audio transmission, but high power consumption.

Typical devices:

Bluetooth headsets/earphones: such as Sony WH-1000XM5, Apple AirPods Pro (support active noise reduction).

Bluetooth speakers: such as JBL Flip 6, Bose SoundLink Revolve+.

In-car Bluetooth systems: such as Ford SYNC, Android Auto in-car modules.

2. Bluetooth Low Energy (Bluetooth Low Energy, BLE)

Features: Ultra-low power consumption (standby current μA level), suitable for intermittent data transmission.

Typical devices:

Health monitoring equipment: Fitbit Charge 6 (heart rate, blood oxygen monitoring), Dexcom G7 blood glucose meter.
Smart home sensors: Aqara temperature and humidity sensors, Philips Hue smart bulbs (via BLE Mesh networking).
Asset tracking tags: AirTag (UWB+BLE dual-mode), Tile Pro.

Ⅱ. Classification by application scenario

1. Consumer electronics

Wearable devices:

Smart watches: Garmin Venu 3 (supports GPS and sports monitoring), Apple Watch Series 9 (ECG electrocardiogram).

Smart bracelets: Xiaomi Mi Band 8 (blood oxygen, sleep monitoring).

Audio devices:

TWS headphones: Samsung Galaxy Buds Pro 2 (ANC active noise reduction).

Bone conduction headphones: Shokz OpenRun Pro (outdoor sports scene optimization).

2. Smart home

Lighting control:

Smart bulbs: Yeelight color bulbs (supports color temperature adjustment, music linkage).

Switch sockets: Sonoff Smart Plug (controlled by BLE or Zigbee).

Security equipment:

Door and window sensors: Aqara M2 (linked camera recording).

Water immersion sensor: Xiaomi Water Leak Sensor (water leak alarm).

3. Automotive electronics

In-vehicle systems:

Bluetooth key: Tesla Model 3 (mobile phone Bluetooth unlocking).

In-vehicle entertainment: Volvo Sensus Connect (supports Spotify streaming).

Diagnostic equipment:

OBD-II Bluetooth adapter: OBDLink MX (reads vehicle fault codes).

4. Industrial and IoT

Positioning and tracking:

Bluetooth beacon: Estimote Indoor Location Beacon (indoor navigation).

Asset tag: Smartrac Cattle Tag (livestock tracking).

Industrial sensors:

Vibration sensor: Sensirion SFM3000 (equipment health monitoring).

Pressure sensor: Honeywell TruStability HSC (industrial pipeline monitoring).

Ⅲ. Classification by functional expansion

1. Bluetooth module (commonly used in development)

Classic Bluetooth module: HC-05/HC-06 (low-cost serial port transparent transmission).

BLE module: HM-10 (supports AT commands), nRF52840 (supports BLE 5.2 and Mesh).

Dual-mode module: TI CC2652R (supports both BLE and Zigbee).

2. Bluetooth gateway

Home gateway: Aqara Gateway 3 (supports BLE + Zigbee + Wi-Fi multi-protocol).

Industrial gateway: Sierra Wireless AirLink RV50X (cellular + BLE dual-mode).

Ⅳ. Technological evolution and new trends

1. Bluetooth 5.0/5.2+

Features: Transmission distance increased to 240 meters (long-distance mode), rate up to 2 Mbps, support for LE Audio (low-latency audio).
Application scenarios: AR/VR devices (such as Meta Quest 3), medical equipment (remote monitoring).

2. Bluetooth Mesh Network

Features: Multi-device self-organizing network, support for large-scale nodes (up to 32,767).
Typical applications: smart building lighting (Philips Hue whole-house solution), warehouse asset tracking.

3. Integration of Bluetooth with other technologies

Bluetooth + UWB: Apple iPhone 15 Pro (precise positioning AirTag).
Bluetooth + Wi-Fi 6E: Samsung Galaxy S23 Ultra (seamless switching of audio streams).

V. Selection recommendations

Based on power consumption requirements:
Long battery life required (such as sensors): BLE devices (such as HM-10 modules) are preferred.

High bandwidth requirements (such as audio): Select classic Bluetooth devices (such as CSR8635 chip solutions).
Based on transmission distance:
Indoor scenarios (<50 meters): ordinary BLE modules.
Outdoor long distance (>100 meters): Long-range BLE or classic Bluetooth + external antenna.
Based on compatibility:
Multi-protocol support: Choose a gateway that supports both BLE and Zigbee (such as Aqara Gateway 3).

VI. Frequently Asked Questions

1. Bluetooth connection is unstable?

Possible reasons: signal interference (Wi-Fi 2.4GHz band conflict), too far away.
Solution: Replace 5GHz Wi-Fi router, add Bluetooth repeater.

2. Bluetooth device cannot be paired?

Possible reasons: device has not entered pairing mode, firmware version is incompatible.
Solution: restart device, update firmware (such as through nRF Connect tool)

Summary

Bluetooth devices cover multiple fields such as audio, health, home, automobile, industry, etc., and technology iteration continues to promote innovation.

Entry-level options: HM-10 BLE module (low-cost development), AirPods Pro (cost-effective audio).
Professional solutions: nRF52840 module (BLE 5.2 + Mesh), Aqara Gateway 3 (multi-protocol fusion).