NFC BLE connection issue

[Roei]

Hi,

I'm using nRF52840, with NFC pairing (based on SDK examples).

The problem is that sometimes, after advertising, my device is waiting and nothing happens. After using a BLE sniffer, I saw that the other client sends a scan request, but my application doesn't receive the CONNECTED event from the soft device. I have a suspicious that it may happen because the scan channels are more crowded than when it success.

Does it make sense? If so, do we have a solution for that?

Thanks!

[Kenneth]

Hi,

Just to avoid confusion: A 'scan' request will not cause a connected event, but a 'connect' request may trigger a connected event.

If you send a connect request but it doesn't trigger a connected event, then either the peripheral have whitelist that prevent the peer to connect and/or there is noise in the environment that prevent the packet to be received (this is a common scenario, for instance <5% of the cases).

Best regards,
Kenneth

[Roei]

Hi Kenneth,

It happens much more than 5%. Is there a way to solve it?

Thanks

[Kenneth]

Have you done any DTM (Direct Test Mode, see example in SDK) testing on the design to ensure that you have a good design?

Do you have any serial interfaces active (e.g. spi, uart, i2c..) while advertising that may impact the radio in some way?