Concepts First
- BLE (Bluetooth Low Energy): the low-power Bluetooth since 4.0, designed for battery devices. The Ai-M62 (BL616) and Ai-M61 (BL618) integrate BLE 5.x, connecting to phones, wearables, and more.
- Central (Master): the device that scans and initiates connections — usually a phone or hub.
- Peripheral (Slave): the device that advertises and waits for connections — usually a sensor or wristband.
- Advertising: the peripheral periodically "announces" itself (name, UUID, custom data); the central sees it and can connect.
- GAP and GATT: GAP handles discoverability/connectivity (advertising, scanning); GATT handles data exchange after connection (Service → Characteristic).
- Service and characteristic: the peripheral organizes data as "service → characteristics (with read/write/notify properties)"; the central finds a characteristic by UUID and reads/writes it.
- Wi-Fi + BLE coexistence: BL616/BL618 are combo chips; both radios work at once (shared RF, scheduled by the SDK).
Roles and SDK Examples
| Role | Description | SDK example | Tutorial page |
|---|---|---|---|
| Peripheral | advertise + serve GATT services | examples/btble/peripheral | BLE Slave |
| Central | scan + connect to peripherals | examples/btble/central | BLE Master |
| Beacon | broadcast only, no connection (iBeacon) | examples/btble/adv (BL616CL only) | ibeacon |
| Provisioning | phone configures Wi-Fi over BLE | examples/wifi/sta/smartconfig_ble | BLE provisioning |
| CLI debug | interactive commands: scan/adv/connect/GATT/throughput | examples/btble/btble_cli | BLE CLI |
| Low power | BLE low power with advertising/connection + power stats | examples/pmu/wl_ble_lp | BLE Low Power |
| Coexistence | Wi-Fi connected while BLE advertises/connects | examples/wifi/coex/wifi_ble | Wi-Fi & BLE Coexistence |
| BLE HID | text/voice over BLE → USB HID keyboard | examples/solution/TvBox/ble_hid_cli_sender (BL616CL only) | BLE HID CLI Sender |
Common Debug Tools
- nRF Connect (Android/iOS): scan, connect, browse GATT services and characteristics — the BLE debugger of choice.
- LightBlue (Android/iOS): another popular BLE debug app.
- Beacon Scope (iOS): view iBeacon advertisements.
- Serial tool at 2000000 baud for module-side logs.
FAQ
The phone cannot find the module's BLE advertisement
Confirm the module is advertising (peripheral example logs Start advertising success); confirm phone Bluetooth is on and location permission is granted (required for Android BLE scanning); the module may still be initializing in the first seconds after power-on — scan again shortly.
Can BLE and Wi-Fi run at the same time
Yes. BL616/BL618 are combo chips; SDK examples (e.g. smartconfig_ble) run both at once. The radios share one RF front end and the SDK schedules them automatically.
Advertising vs connection
Advertising is one-way "shouting" that anyone can hear, with no connection. A connection is a two-way link between central and peripheral, after which GATT reads/writes work. Beacons only advertise.
Questions?
For other questions, please visit the unified Q&A and discussion area: Ai-Thinker Discussions