• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 51 subscribers
  • Views 278 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

CC2564CSTBTBLESW: how do I make CC2564C more responsive to Inquiry?

Mir A
Prodigy 60 points
Part Number: CC2564CSTBTBLESW
Other Parts Discussed in Thread: CC2564C

Tool/software:

Hello,

In our application we use version 5.1.1.1 of the stack.

We perform the Inquiry from a PC, and expect to find our machine, equipped with the BT module, in the list of inquiry responses:

  • it is usually there when there's only one or two machines turned on.
  • if we have a bigger number, like 25 machines turned on at the same time, about 0,7 meter distance between them, we need to repeat the Inquiry (each one duration 30s) 4 to 6 times before getting an answer which lists all 25 machines. In the first few inquiries we get just 3 to 5 answers, then in the following retries the list increases until we get a complete list.
  • with our legacy module (which was just BT Classic, no dual mode), we needed just one 30 sec Inquiry to find all machines.
  • we tried with different PCs but we got the same result

We already tried to change the "Inquiry Scan" parameters, using the

HCI_Write_Inquiry_Scan_Activity(BT,960,36,&Result); 

and then verifying with the HCI_Read_Inquiry_Scan_Activity() that the new values are set. We've seen that the default values after boot were Interv=4096 and Window=18, and with the new values the situation is better but we still have the behaviour described above.

So, is it possible to make the CC2564C more responsive to Inquiries?

Is it just a matter of decreasing the Interval and increasing the WindowSize of the Inquiry_Scan, or can we try something else?

Thanks for any suggestion

  • 0
    TI__Genius 14601 points

    Hello,

    It seems to be an issue of too much noise, the only work around is as you suggested, decrease the Scan Interval, Increase the Scan Window, Increase the Scan Duration. This will hopefully allow the receiver to scan the ble device you are looking for in one inquiry instead of having to call it multiple times.

    Best,

    Rogelio

  • 0 in reply to RogelioD
    Prodigy 60 points

    Thanks. I've got some more questions, I hope I can get some more insights on this topic.

    Our application needs more than one SPP connection open at the same time. Just to make sure that I understand how much impact the Scan Interval and Window have on already established connections, during the Scan Window the module will only listen for Inquiry and will pause any other communication?

    I've seen that in the library there's also the HCI_Write_Inquiry_Scan_Type() which makes possible to select between Standard scan and Interlaced scan. The default is Standard scan. I've just tried both without seeing any difference. Should I have expected this in my situation, or am I doing something wrong?

    Last question: do the settings for Scan Window, Duration and Type take effect immediately, or do I need to perform some other manouver, like for example calling again the function to make the module Discoverable?

  • +1 in reply to Mir A
    TI__Genius 14601 points

    Hello,

    Mir A said:
    Our application needs more than one SPP connection open at the same time. Just to make sure that I understand how much impact the Scan Interval and Window have on already established connections, during the Scan Window the module will only listen for Inquiry and will pause any other communication?

    Yes it is a trade off unfortunately, you will have less bandwidth while scanning and also a bit more power consumption.

    Mir A said:
    I've seen that in the library there's also the HCI_Write_Inquiry_Scan_Type() which makes possible to select between Standard scan and Interlaced scan. The default is Standard scan. I've just tried both without seeing any difference. Should I have expected this in my situation, or am I doing something wrong?

    In your case I would stick to defualt.

    Mir A said:
    Last question: do the settings for Scan Window, Duration and Type take effect immediately, or do I need to perform some other manouver, like for example calling again the function to make the module Discoverable?

    You would have to stop scanning, change the parameters, then restart the scan.

    Best,

    Rogelio

  • 0 in reply to RogelioD
    Prodigy 60 points

    ok, thanks for all the tips