52840 The scan is abnormal. The Bluetooth device cannot be scanned for a long time

[Ayden_Hao]

Hello, Karl Ylvisaker. When I use 52840 scan, I sometimes fail to scan other Bluetooth devices for a long time, but the scan will resume after a long time. Other Bluetooth devices are working normally. I configured the scanning window interval to be 1200 and the scanning interval to be 2400. Could you please help me think about what might be the cause

[Karl Ylvisaker]

Hello,

The values for the scan interval and window are given in units of 625 µs each, and so your configuration to use a scanning window of 1200 with a scanning interval of 2400 means that you will scan for 750 ms each 1500 ms. What are the advertising parameters of your peripheral device?
Could you elaborate on what you mean when you say 'scan will resume after a long time' - how long is the time you are seeing in between each scan report?

Best regards,
Karl

[Ayden_Hao]

The peripheral advertising parameter is 1s, and the scanning device appeared for nearly one hour and could not scan the peripheral device. Nothing was done during this period and it will recover on its own. I wonder if there is a configuration that causes the scan to be abnormal

[Karl Ylvisaker]

That's strange. Was the central able to scan any other devices at all in this period?
Could you clarify whether you are working with a nRF52840 DK or a custom board?
Is your code based on an example - and if so, which one? - and did you see any unexpected logs or similar on the scanning device when this test ran?

Lastly, have you externally verified that the target peripheral device is advertising as expected? If so, how have you verified this?

Best regards,
Karl