Why I receive unreliable SCAN_RSP data?

[Piotr Romaniuk]

Posted on May 10, 2018 at 14:35

Hi,

My device is Bluetooth LE peripheral that is based on BlueNRG-2 and STM32 connected via SPI.

I would like to present some measurement data in SCAN_RSP to central devices.

The measurement is performed every 1 second and in this period I update scan_rsp data by:

   hci_le_set_scan_response_data() 

The data that I pass to above function has following format:

0:        22                       - AD_Len1:        0xFF                  - AD_Type = MANUFACT_SPEC.

2-23:  custom_data[22] - AD_Data - my measurements

In my central device I receive only about 30% of correct SCAN_RSP, other have empty data:

11662 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -53 dBm :: [24]: 16 ff 01 10 99 1c 70 00 15 00 80 03 80 fe c0 c0 00 00 6c 01 00 17 01 00

14757 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -60 dBm :: [0]:

19177 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -60 dBm :: [24]: 16 ff 01 10 bb 93 71 00 15 00 80 03 40 ff 40 c1 00 00 6c 01 00 17 01 00

22272 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -60 dBm :: [0]:

24485 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [24]: 16 ff 01 10 dd 0a 73 00 15 00 40 03 00 ff 80 c0 00 00 6c 01 00 17 01 00

27532 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -60 dBm :: [0]:

29742 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [24]: 16 ff 01 10 ff 81 74 00 15 00 80 03 80 ff 40 c1 00 00 6c 01 00 17 01 00

34999 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [24]: 16 ff 01 10 11 f9 75 00 15 00 40 03 c0 fe 00 c1 00 00 6c 01 00 17 01 00

38047 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -60 dBm :: [0]:

40254 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [0]:

41363 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -52 dBm :: [24]: 16 ff 01 10 33 70 77 00 15 00 80 03 00 ff 00 c1 00 00 6c 01 00 17 01 00

44410 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -60 dBm :: [0]:

46620 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -54 dBm :: [0]:

47725 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [24]: 16 ff 01 10 55 e7 78 00 15 00 80 03 40 ff c0 c0 00 00 6c 01 00 17 01 00

50771 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -59 dBm :: [0]:

54086 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -51 dBm :: [24]: 16 ff 01 10 77 5e 7a 00 15 00 40 03 40 ff c0 c0 00 00 6c 01 00 17 01 00

57131 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -61 dBm :: [0]:

59342 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [24]: 16 ff 01 10 99 d5 7b 00 15 00 40 03 c0 fe 40 c0 00 00 6c 01 00 17 01 00

62389 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -60 dBm :: [0]:

64600 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [0]:

65705 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [24]: 16 ff 01 10 bb 4c 7d 00 15 00 c0 03 40 ff 80 c1 00 00 6c 01 00 17 01 00

68802 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -60 dBm :: [0]:

71012 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [24]: 16 ff 01 10 dd c3 7e 00 15 00 80 03 80 ff 00 c1 00 00 6c 01 00 17 01 00

74109 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -61 dBm :: [0]:

76319 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -56 dBm :: [0]:

77425 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -55 dBm :: [24]: 16 ff 01 10 1f 3b 80 00 15 00 40 03 40 ff 40 c1 00 00 6c 01 00 16 01 00

80519 0> SCAN_RSP, xx:xx:xx:xx:xx:xx RSSI -61 dBm :: [0]:

Why data are empty for some SCAN_RSP?

Kind regards,

Piotr #scan_rsp #bluenrg-2

[Piotr Romaniuk · Accepted solution]

Posted on May 11, 2018 at 06:29

My mistake.

I overlooked that after each connection I call SetDiscoverable where was setting SCAN-RSP data to null.

Regards,

Piotr