3 Replies Latest reply on Feb 6, 2018 11:16 PM by BoonT_56

    Advertisement Stops Unexpectedly

    jawi_736556

      We are using a BCM20736 IC, with SDK 2.2.3.

       

      Our firmware initializes the device and starts advertising. In normal operation, the device will continue to advertise forever. However, sometimes we notice that advertisement stops unexpectedly. This happens in about 1 in 10 BCM parts (out of a sample of 120 devices). When advertisements stop, it can happen in a couple minutes, or a couple hours. No advertisements are detected by a sniffer.

       

      We instrumented our code to call the bleprofile_GetDiscoverable(void) function periodically, to monitor what the device thought its advertising state was. We toggle an I/O line based on the return from the function. (NO_DISCOVERABLE = LOW, DISCOVERABLE = HIGH). We never saw this line go LOW when the problem occurred. This may imply that the the radio hardware is not transmitting, despite the condition of the radio firmware state machine.

       

      Removing/reapplying power starts advertisements again, but a failing unit will fail again. Most units never fail, even after several days of continuous operation.

       

      Some IC date codes seem to show more failures than others, and some date codes show no failures.

       

      Replacing the BCM IC on a failing PCB causes the problem to disappear -- the problem seems to follow the BCM IC, not the rest of the hardware.

       

      Two other posts ("Advertisement seems to be flakey" and "Prototype boards are failing with issue similar to one previously reported") describe somewhat similar problems.

       

      Thanks,

      Jackson

        • 1. Re: Advertisement Stops Unexpectedly
          BoonT_56

          Do you think you can take of your keep-on-failing boards and load it with the hello sensor app? This may give some clues on the

          health of the hardware and perhaps layout.

          • 2. Re: Advertisement Stops Unexpectedly
            jawi_736556

            We have tried that (as part of a Case we have opened).  I posted on the Forum to try to get some community feedback as well.

             

            The result of that test seems to show that the hello_sensor application does not fail. 

             

            But, the most difficult part of the problem is that some ICs fail consistently, while others do not fail at all, even when loaded with the same code, and run for several days.  So, I don't believe the failure is only related to the code.  There seems to be some relationship between the code and the hardware which is popping up intermittently. 

             

            I was especially intrigued by the observation in the "Advertisement seems to be flakey" post that the problem was traced to a faulty Tag.  The poster replaced the Tag and the problem did not reappear.

            • 3. Re: Advertisement Stops Unexpectedly
              BoonT_56

              You meant to say that on those bad boards/parts, the hello sensor app did not fail?

               

              If you have a hunch that the IC could be the issue here, then please discuss this with the engineer who is looking into your case. We usually may need to do a FA for such cases.