Notes / Communication Protocols
Wireless: choosing BLE, Wi-Fi or LoRa
Compare by four things (range, speed, power and infrastructure) and the right wireless option for a project becomes clear.
| Type | Range | Speed | Power | Characteristics |
|---|---|---|---|---|
| BLE | Up to tens of m | ~1 Mbps | Very low | Connects directly to a smartphone |
| Classic Bluetooth | ~10 m | ~2 Mbps | Medium | Serial modules such as the HC-05, audio |
| Wi-Fi | Up to tens of m | Tens of Mbps and up | High | Direct internet connection (ESP32) |
| LoRa | Several km | A few kbps | Very low | Long-range sensors; needs a gateway |
| Zigbee / Thread | Up to tens of m (mesh) | 250 kbps | Low | Smart-home mesh |
Questions for choosing
- Controlled from a phone app? → BLE
- Sending straight to an internet server? → Wi-Fi (or LTE-M)
- Years on a battery, kilometres of range? → LoRa
- A hobby project you want working quickly? → HC-05 Bluetooth serial
BLE concepts
A device exposes data as GATT services and characteristics, and the phone reads or writes a characteristic or subscribes to notifications. If you need "BLE that behaves like a UART", use a conventional service such as the Nordic UART Service.
Hardware
Using a pre-certified module reduces the burden of radio certification. Around the antenna, respect the keep-out area for ground and metal given in the module's datasheet.