NCS disconnect with reason 0x08 connection timeout when using bluetooth peripheral uart application

[Babu venkat]

Hello,

We are using  NCS NRF connect SDK 2.4 with bluetooth peripheral uart sample application.

We see sometimes disconnect call back is called with reason 0x08. After this device is not broadcasting.

Could you please clarify the below.

1: Reason for this disconnect call back callled, is this because of local host or remote host?.

2: Is there anyway we can increase the connection time out value?.

3: What action needs to be done to make sure device broadcasts the manufacturing data in this scenario?.

[Simonr]

Hi

Naeem asked me to take over this case as he's currently otherwise engaged. 

You say you're still seeing a connection timeout, after how long do you see this timeout error occur? The preferred timeout you've set is 4 seconds (400 * 10 ms), so if this timeout is used, the timeout will occur of ~4 seconds after a connection. If you set the CONFIG_BT_PERIPHERAL_PREF_TIMEOUT = 65535, that will represent no specific value.

If you could provide a sniffer trace of what's happening on the air when connecting that might give us a better idea of what exactly is causing this issue here. You can use a dedicated BLE sniffer or a spare nRF52 DK and the nRF Sniffer in Wireshark to get a sniffer trace of the BLE connection.

Best regards,

Simon

[Babu venkat]

Thanks for the reply. Will share the sniffer trace of the BLE connection soon. 

My central device (Iphone scanner app) scans my NRF52DK BLE device and connects to it .It gets disconnected  with connection timeout error 0x08 that  is seen at both the ends sometimes after 3 mins or 5 mins or 15 mins. It all depends on the exchange of data between the IOS central scanner device and my BLE peripheral. 

We are using peripheral_uart  sample application using NRF connect 2.4 SDK.  We have set the above additional connection parameters in the prj.conf file. Could you please share the below details.

1: What happens if we set  CONFIG_BT_PERIPHERAL_PREF_TIMEOUT = 65535 in the peripheral_uart sample application?.  

2: Do we  need to set this supervision timeout in the Central (IOS scanner) application as well?. If so is there a provision to do this in the IOS central scnner application?.

3: Is there anyway to send these connection parameters from peripheral to central IOS application by means of some GATT services?.

4: How do we know whether this disconnection (connection timeout 0x08)  is caused because of peripheral or central IOS device?.

5: Is there any sample 2.4 SDK application available to implement the GATT initialization and parameters settings and also sending some service characteristics?. 

Thanks.