[Discussion] One minute to understand BLE advertising data package

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[Discussion] One minute to understand BLE advertising data package

Note: only registered user could see all pictures by log in. One minute to understand BLE advertising data package BLE =》 BTLE （Bluetooth Low Energy） 1. How to capture BLE advertising data (full channel at 37,38,39 simutanueously)    * Hardware：One BLE device (has feature of advertising);          One HOLLONG BLE SNIFFER    * Software：Hollong BLE sniffer software         Download： http://www.viewtool.com/index.ph ... 0option=com_content 2. Profile    BLE Advertising package introduction：    * Payload data maximum length： 37 bytes    * Advertising channels：37，38，39 （hopping）    * Transmission power：usually 0dBm, Maximum 10dBm          In each section below, pay attention on blue color marked portion (the raw data captured) and related data interpret portion（data interpretation） 3. Access Address    It is fixed length (4 bytes) and fixed data (0x8e89bed6) used for master device access address identification. 4. Header Info    Fixed 2 bytes：used by 16 bits    BIT[0:3]：Advertising package（PDUs) type，there are following PDU Types：         PDU Type         b3b2b1b0 Packet Name         0000 ADV_IND： connectable undirected advertising event         0001 ADV_DIRECT_IND：connectable directed advertising event         0010 ADV_NONCONN_IND：non-connectable undirected advertising event         0011 SCAN_REQ：scan request         0100 SCAN_RSP: scan response         0101 CONNECT_REQ：connection request         0110 ADV_SCAN_IND：scannable undirected advertising event         0111-1111 Reserved    BIT[4:5]：Reserved    BIT[6]：RxAdd    BIT[7]：TxAdd    BIT[8:13]：advertising data length （Maximum 37 bytes)    BIT[14:15]：Reserved 5. MAC Address    Fixed 6 bytes 6. Advertising data：flag field    02 01 06    02：field length 2 bytes 　 01: as flag    06：BIT1,BIT2 = 1， based on definition below, interept as： 　　　* LE General Discoverable Mode       * BR/EDR Not Supported (i.e. bit 37 of LMP Extended Feature bits Page 0) 0 LE Limited Discoverable Mode 1 LE General Discoverable Mode 2 BR/EDR Not Supported (i.e. bit 37 of LMP Extended Feature bits Page 0) 3 Simultaneous LE and BR/EDR to Same Device Capa- ble (Controller) (i.e. bit 49 of LMP Extended Feature bits Page 0) 4 Simultaneous LE and BR/EDR to Same Device Capa- ble (Host) (i.e. bit 66 of LMP Extended Feature bits Page 1) 5..7 Reserved 7. Service tag field    03 03 02 18    03：field length 2 bytes 　 03: service tag field    02 18：=》18 02 => Immediate Alert Service 8. Device name field    0e 09 45 .... 6d 65    0e: field length 14 bytes    09：device name field    45，。。。6d 65: device name (ASCII) 9. CRC：       Fixed 3 bytes Get complete Hollong BLE Sniffer captured data file: Get advertising data format specification: