4 Replies Latest reply on May 12, 2015 12:31 AM by userc_14409 Branched from an earlier discussion.

    Question about scan intervals

    userc_14409

      What are the minimum scan interval and window values?

        • 1. Re: Question about scan intervals
          MichaelF_56

          Take a look at this thread for a description of high/low duty scans: Re: BLE_CEN_CFG intervals and windows

           

          Recall that the Scan Interval indicates how often you want to scan, while the Scan Window indicates the duration of the scan.

           

          So if the Scan interval is 100 and the Scan Window is 10, the part will listen for 10 slots (.625ms) and go to sleep for 90 slots.

           

          Then listen for 10 slots then go to sleep for 90...

           

          The proper setting of these values depend on your latency and power consumption requirements.

          • 2. Re: Question about scan intervals
            userc_14409

            OK thanks that makes sense, but are there minimums? like for blecm_startAdv() the minimum interval is 20ms, so is there a minimum interval and window for scanning?

            • 3. Re: Question about scan intervals
              BoonT_56

              In the thread attached by mwf_mmfae above, scanning is viewed in the context of whether is it a heavy-duty or low-duty scan. Essentially, one is defining how often should the radio be listening, and for how long a duration when it listens. I believe some folks are using a minimum of 2.5ms, all the way up to 10.24s. But "window" must always be shorter than "interval". Any particular reason why you are looking at a minimum?

              • 4. Re: Question about scan intervals
                userc_14409

                I just wanted to make sure I didn't hit a value that broke it without realizing it since I noticed in the comments for the blecm_startAdv() function it says the minimum is 20ms and my debugging capabilities are rather limited. Thanks for the answers!