Bluetooth connection and serial port sending

[xiaobai]

Now I come across such a problem, when the device is sending serial port data, at the same time to the mobile phone and bluetooth connection for related business processing, the bluetooth will be disconnected for a timeout.Now suspect is due to the serial port send interrupt events caused, what can be resolved?

[xiaobai]

I am connecting a mobile phone. Due to the product features, it is only used for mobile phone connection, so I haven't used other devices to connect ble.My project is based on ble_app_uart in nRF52 SDK.

[Sigurd]

xiaobai said:

I am connecting a mobile phone

 Does the log on the phone show any error codes? I recommend testing with nRF Connect for mobile. You can bring up the log if you swipe from left to right when in the device tab, or by clicking on the "3 dots button" and click "Show log".

[xiaobai]

When using the nRF Connect tool to Connect, the connection will still be disconnected when sending big data through the serial port. The log on the tool shows Error 8(0x8): GATT CONN TIMEOUT, which is the same reason I described before.

[Sigurd]

So you are getting BLE_GAP_EVT_DISCONNECTED event with reason BLE_HCI_CONNECTION_TIMEOUT on the nRF52.

And on the phone you get Error 8(0x8): GATT CONN TIMEOUT

To see what really happens on-air you need to take a sniffer trace. If you have a spare DK, you can use nRF Sniffer to take the trace. 

You can download nRF Sniffer here:https://www.nordicsemi.com/Software-and-tools/Development-Tools/nRF-Sniffer-for-Bluetooth-LE/Download#infotabs

Documentation for the nRF Sniffer here: https://infocenter.nordicsemi.com/topic/ug_sniffer_ble/UG/sniffer_ble/intro.html

[xiaobai]

Sorry, this problem is related to our hardware design.Due to the NB module, the data may be out of order due to the fact that the frequency of NB sending data is the same as the frequency of bluetooth transmitting.Now I suspect this is the reason. May I ask if you have any good comments or Suggestions to offer us to solve this problem?