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?

[Hung Bui]

@elgogi: This meant there was no missing packet on BLE link itself. The missing notification values was most likely because the packet wasn't queued in the transmission queue because the queue was full for example. Have you checked and make sure you only increase the counter if the call sd_ble_gatts_hvx() returns successful (NRF_SUCCESS) ?