Question about specifying Advertising Interval for BlueNRG

[lance]

Posted on July 13, 2017 at 23:05

I need to adjust the Advertising Intervals (min/max) associated with the ''

Bluehci_Gap_Set_Limited_Discoverable

'' command which is described on pages 30-31 of the UM1755 BlueNRG Bluetooth LE stack ACI User Manual (linked on the BlueNRG product page).

This command has the parameters:

      

where I need to understand the details of Adv_Interval_Min and Adv_Interval_Max.

However no details are provided.   The User Manual says this about these parameters:

      

and in the detailed listing of the command parameters,  these two parameters are entirely missing!

Can you please provide details for these two parameters:  Adv_Interval_Min and Adv_Interval_Max

• How many bytes each?
• If > 1 bytes are they big or little-endian?
• What are the time units?   In other words,  if I specify a value of 1 (decimal),  what will the corresponding advertising interval be?

If this information is available somewhere,  please point me to it.

Thank you very much!

#adv_interval_min #advertising-interval #adv_interval_max #bluehci_gap_set_limited_discoverable

[Antonio Vilei · Accepted solution]

Posted on July 14, 2017 at 10:50

Dear Lance,

they are 2-byte little endian parameters. As for the endianess, please notice that it's already handled by the library included in the SW package.

Parameter

Size

Description

Advertising_Interval_Min

2

Minimum advertising interval. Range: 0x0020 to 0x4000 Time = N * 0.625 msec Time Range: 20 ms to 10.24 sec

Advertising_Interval_Max

2

Maximum advertising interval. Range: 0x0020 to 0x4000 Time = N * 0.625 msec Time Range: 20 ms to 10.24 sec

[Antonio Vilei]

Posted on July 14, 2017 at 10:52

If you specify 1 as the parameter, the corresponding interval will be  1 * 0.625 ms, i.e. 0.625 ms.

Hope that helps,

Antonio

[lance]

Posted on July 14, 2017 at 14:50

Hi Antonio,

Thanks very much for the answers,  it helps very much!

I'm curious:  where did this information come from?   Is there some other ST manual or spec that has it listed?   It would be good for me to know for future reference.

Regards,

Lance

[Antonio Vilei]

Posted on July 18, 2017 at 10:50

Hi Lance,

this information is included in the

http://www.st.com/content/st_com/en/products/embedded-software/wireless-connectivity-software/stsw-bnrgui.html

 documentation. The BlueNRG GUI is a graphical user interface application for PC that can be used to interact and evaluate the capabilities of the BlueNRG family. By using the GUI, you can also get hints about the parameters.

Besides, the GUI will help you with service and characteristic creation and discovery.

Best regards,

Antonio

[lance]

Posted on July 18, 2017 at 13:56

Thank you Antonio.  I'm getting involved in a project in the late prototype stage,  so I have not had a chance to spend time with the BlueNRG GUI.  But I appreciate knowing where to look if I have other questions.

Regards,

Lance