Start losing frames on LL_CHANNEL_MAP_REQ

[elgogi]

Hi

I'm using nrf51422 to send periodically a frame through ble_nus service to the Nordic nRF UART app. One of the frame data is the message count number, that is reset every 64 counts.

Everything goes smooth until the master sends LL_CHANNEL_MAP_REQ. From then on, the SoC starts sending only some of the frames, others are omitted. Why should this command produce this behaviour?

I'm using SDK v7.1.0 with S310 softdevice. I attach the sniffer capture if that helps.

Thanks!

Nexus5.pcapng

[Hung Bui]

@elgogi: Could you explain on the observation that after LL_CHANNEL_MAP_REQ there are some packet missing ?

I couldn't find that in the sniffer trace, the channel hopping was jumping correctly.

I saw that the disconnection was from the phone side, when notification was sent and acked until it is disconnected.

Which app did you use to test the device, have you tried to use the Master Control Panel app?

[elgogi]

Thanks for the quick reply. If you check the notification value, you will see that the first digit is a frame counter that goes from 0 to 63 and so on. Before receiving LL_CHANNEL_MAP_REQ every notification value comes with this consecutive counter correctly, but after receiving it there are some notifications missing.

This is tested on a Nexus 5 (Android 5.0.1) with nRF UART app and also with nRF Master Control Panel app with the same result. However, a Nexus 4 (Android 4.4.4) hasn't got such issue as it is not sending the LL_CHANNEL_MAP_REQ.

No problem about disconnection, I did it on purpose on the phone side.