BLE disconnection with xiaomi

[Roei]

Hi,

I have an application on NRF52840. I'm able to connect successfully to mobile devices, with min connection interval of 7.5 and max of 30.

However, when I try to connect to a xiaomi mobile, connection is lost after about a minute.

Is there any chance that I need to change the connection parameters, so all the mobiles will be able to connect?

Thanks!

[Kenneth]

I assume based on your description that you have tested that if you increase the max connection interval then it stays connected?

If is the case, then you may solve your problem by either increase max connection interval, or choose to not disconnect:

In conn_params_init() make sure that:
cp_init.disconnect_on_fail = false;

[Roei]

I tried to increase the max connection interval but it didn't help.

If I choose not to disconnect, isn't that problematic to stay connected with problems?

Thanks!

[Kenneth]

Roei said:

If I choose not to disconnect, isn't that problematic to stay connected with problems?

The "problem" may be longer latency, if that is critical you can of course disconnect, but then no data is sent. It's up to you really. 

Roei said:

I tried to increase the max connection interval but it didn't help.

This means that the problem is not related to connection interval.

How frequently are you sending data from the peripheral to the phone in this case before disconnect? 

[Roei]

I tried to connect my NRF device to a mobile using NRF connect. I don't know exactly how frequently the data is sent. Can it be related?

[Kenneth]

I suggest that you read data every ~10 seconds and check if the problem persists. An on-air sniffer log would likely pin-point the issue directly:
https://www.nordicsemi.com/Software-and-tools/Development-Tools/nRF-Sniffer-for-Bluetooth-LE/