Bluetooth protocol got layers
Controller stack (dont bother)
- PHY: hardware radio
- Baseband: timing
- Link Controller: device stuff
- Link Manager: another layer
- Device Manager
Host Stack:
- L2CAP
- SMP
- GAP
- ATT/GATT (LE)
- SDP
L2CAP
Logical Link Control and Adaption Layer protocol
Functions for data comm.
GAP
Generic Access Profile, same as Bluetooth Low Energy > GAP
SDP
Service Discovery API
https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/bluetooth/esp_sdp.html