📝BLE

(Bluetooth Low Energy)

BLE advertising frame:

PreambleAccess AddressPDUCRC
1 octet4 octets2 to 39(4.0) or 257(5.0) octets3 octets

For all advertising channels, Access Address is always 0x8E89BED6.

PDU format:

Header (16 bits)Payload

Header format (4.0):

4b PDU Type2b RFU1b TxAdd1b RxAdd6b Length2b RFU

Header format (5.0):

4b PDU Type1b RFU1b ChSel1b TxAdd1b RxAdd8b Length
PDU typePacket Namecomment
0000ADVINDbroadcast advertisement
0001ADVDIRECTINDdirected advertising
0010ADVNONCONNINDbeacons
0011SCANREQfor connection
0100SCANRSPfor connection
0101CONNECTREQfor connection
0110ADVSCANIDadditional info on scan

Max A. recommendation:

  1. getting started with bluetooth low energy
  2. https://habr.com/ru/post/319244/
  3. bluetooth core specification 5.2 pdf