• State
  • Locked Locked
  • Replies 7 replies
  • Subscribers 50 subscribers
  • Views 440 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.

CC2540 Keyfob update connection parameter problem

Jun Feng Hu
Prodigy 230 points

I comply Apple rule about connection interval update, such as timeout=6s, min=0.5s, max=1s, latency=0.

But every time i update connection interval parameters. iPhone5 will disconnect with CC2540. iPhone4s is better than iPhone5, but iphone4s will lose connection.

So i think if my 32.768K is bad?

I measured 32.768K crystal, and Peak-Peak is 300mV,  i change capacity from 6.8pf-20pf.

But same problem happened.

I measured 32MHZ crystal, and Peak-Peak is 500mV.

So any other people have this problem.

  • 0
    TI__Genius 12545 points

    Jun Feng,

    Use the PMUX register to output the 32kHz clock on the GPIO and measure the frequency. Also, varying the crystal cap is only done to compensate for the parastic cap already present. The goal is to get as close as possible to 32.768KHz as possible.

    There could be other issues in play, other than the clock. The keyfob should be able to connect and stay connected. 

  • 0 in reply to Chatto
    Prodigy 230 points

    There could be other issues in play?

    What do you mean about "play"?

    Because i measure 32K by GPIO output, and it has 30ppm accuracy, so i think 32K is ok.

    Also i measure 32M, it has 20ppm accuracy.

    I download stack 1.3.0 to key fob,  and connection interval is 500ms or 1000ms, it also lose connection from ipod touch 5th(IOS 6.1.3).

    So any other advice ? 

  • 0 in reply to Jun Feng Hu
    Prodigy 230 points

    I tested stack 1.3.1 to key fob, interval is 500ms, It also lose connection from ipod.

    So i think TI's stack maybe has some problem?

    Anybody found this problem?

  • 0 in reply to Chatto
    Prodigy 230 points

    There could be other issues in play? What do you mean about "play"? Because i measure 32K by GPIO output, and it has 30ppm accuracy, so i think 32K is ok. Also i measure 32M, it has 20ppm accuracy. I download stack 1.3.0 to key fob, and connection interval is 500ms or 1000ms, it also lose connection from ipod touch 5th(IOS 6.1.3). So any other advice ?

  • 0 in reply to Jun Feng Hu
    TI__Mastermind 23440 points

    Hi Jun,

    Does the connection only drop when you request a parameter update?

    Have you tried other, even more compliant parameters? What is the response in the sniffer from the iOS device? Param Update Accepted or Rejected?

    You could try waiting some seconds after connection establish before you update the parameters via the update request.

    BR,
    Aslak 

  • 0 in reply to Aslak N.
    Prodigy 230 points

    Thanks for your respond.

    I try waiting some seconds, such as 60s, but it failed again.

    Even more compliant parametes? can you advise me?

    BTW, i test with 1.3.1 in keyfob. i just change update flag and parameters. So can you test on your side with your keyfob? Does it perform same?

    Also, i will capture packet in the near future.