The problem is that the response takes more than 0.3s.

[applesan]

[ Problem ].
When communicating with the TestApp as shown below, it is taking an unusually long time to get a response.
The problem is that the response takes more than 0.3s.

This can be fixed by rebooting the FW and doing a factory reset.

[ Request ].
The response is immediate (0.3s).
Please fix it so that the response time is immediate (less than 0.1s).
Please share how to fix it.

getVersion（1.5s） 2021-05-17 14:41:58.293 4210-4210/com.jstyle.test1935 I/System.out: Log:: req 2021-05-17 14:41:59.768 4210-4210/com.jstyle.test1935 I/System.out: Log:: get getBattery（1.7s） 2021-05-17 14:43:22.607 4210-4210/com.jstyle.test1935 I/System.out: Log:: req 2021-05-17 14:43:24.370 4210-4210/com.jstyle.test1935 I/System.out: Log:: get getActivityDetailData（2s） 2021-05-17 14:49:05.942 4210-4210/com.jstyle.test1935 I/System.out: Log:: req 2021-05-17 14:49:07.826 4210-4210/com.jstyle.test1935 I/System.out: Log:: get 2021-05-17 14:49:07.827 4210-4210/com.jstyle.test1935 I/System.out: Log:: get getDetailSleepData（1.5s） 2021-05-17 14:53:18.311 4210-4210/com.jstyle.test1935 I/System.out: Log:: req 2021-05-17 14:53:19.831 4210-4210/com.jstyle.test1935 I/System.out: Log:: get 2021-05-17 14:53:19.832 4210-4210/com.jstyle.test1935 I/System.out: Log:: get FWからレスポンスが帰ってくるまでの時間 getVersion（1.5s）
 2021-05-17 14:41:58.293 リクエスト 
2021-05-17 14:41:59.768 レスポンス getBattery（1.7s）
 2021-05-17 14:43:22.607 リクエスト 
2021-05-17 14:43:24.370 レスポンス getActivityDetailData（2s） 
2021-05-17 14:49:05.942 リクエスト 
2021-05-17 14:49:07.827 レスポンス getDetailSleepData（1.5s） 
2021-05-17 14:53:18.311 リクエスト 
2021-05-17 14:53:19.832 レスポンス

[Vidar Berg]

Hello,

I don't know what the factory reset does on your device, so difficult to say why it might impacts the response time. Have you tried to request a shorter BLE connection interval (Connection Parameters Negotiation) to see if that helps?

Best regards,

Vidar

[applesan]

Hi, Vidar

Thank you for your reply.

We use nRF52832 for the BLE.

For the connection interval, we set 7.5ms as the fastest number, but sometimes it becomes very slow as I mentioned.

I am not setting slow numbers at any places, and can't know how this is happening.
Is there any way that this happens by nRF52832 itself or in some cases?

Best

[Vidar Berg]

Hi,

The Softdevice will never automatically request a different connection interval unless the application explicitly asks for it. Do you have Bluetooth Sniffer you can use (e.g. nRF Sniffer for Bluetooth LE). A sniffer trace may help us show what's actually going on.   

Best regards,

Vidar

[applesan]

Hi,

Thank you for your reply.

So no chance that some other matters slow down the interval?

About the Sniffer, I have never tried it at my side, so will try it. I will try and let you know how it went with a concrete log.

Thank you,

Applesan

[Vidar Berg]

The central and peripheral are both capabable of requesting a slower connection interval, but I'm not sure if that's what's happening. Just let me know if you run into any problem with the sniffer set-up.