Connection interval issue between nRF51822 and iOS device

[Anand Ramashetty]

Hi,

Here is the issue details.

I have my application loaded on the nRF51822 controller and it acts as a peripheral. The IOS device acts as a central.

The connection interval set on the nRF is as below.

#define MIN_CONN_INTERVAL 16(20msec) #define MAX_CONN_INTERVAL 60(75msec) #define SLAVE_LATENCY 2 #define CONN_SUP_TIMEOUT 400 (4sec).

The testing scenario is like that.

I have send the command from the ioS device to nRF , nRF send the command to STM32 controller and it got executed with in 3 sec and it send the ack to nRF , inturn nRF passes the ack to iOS device. After receiving the ack from nRF, iOS send the disconnection command to nRF(the whole process happens in 3-4 second). But the connection will be open for a minimum of 10 second as shown in the attached snapshot and then it closes the connection.

can you please let us the reason for this. It consumes more power when in connection state.

Note : If you are not able to receive the snapshot please let me know.

Regards, Anand

[Anand Ramashetty]

I have posted the same question in IOS apple developer forum. No answer from them.

Regards, Anand

[Anand Ramashetty]

Hi Stefan,

I have tested the our nRF application with MCP. It connects and disconnects as soon as you send the connect/disconnect command from the MCP. Where as with iOS application it tooks 10 seconds to disconnect even though you send the disconnect command earlier than 10 seconds.

Regards, Anand Regards, Anand

[Stefan Birnir Sverrisson]

Hi Anand

Can you please report what IOS version you have, what iphone version, and what app you are using?

Perhaps the best method is to use a BLE sniffer to identify the problem, i.e. to identify what is the difference between the disconnect from MCP and from IOS.

In my previous test with the IOS nRFToolbox HRM app and the ble_app_hrs example running on the nRF51 DK board, I see that the advertising led starts to blink immediately after I press disconnect on the IPhone (i.e. in the nRFToolbox HRM app). How do you see your disconnection? on the nRF51 device or on the iphone?

If you create a support case in the support portal, you can attach images, code and such. Go to www.nordicsemi.com an log in. Press "My page" and then "Register new case" in order to create a support case. Notify me here when you have created your case so I can notice your case and see your snapshot

[Stefan Birnir Sverrisson]

I will also try to test with nRF_Toolbox_master UART app and try to reproduce the problem.

[Anand Ramashetty]

Hi Stefan, I have registered the new case and attached the snapshot .

The IOS version we are using is as follows. Ios 8.1.2 Device : Ipad3

The app we are using is the nRF_Toolbox_master UART which communicates with our nRF application which we developed.

You are right , I tested that also, i have checked the disconnet command coming from IOS and MCP device, both are same.(LL_TERMINATE_IND)

I saw the disconnection in the NRF side which is connected across the CRO.The IOS device device is sending the disonnection command in 3 second but the disonnection happens after 30 seconds only.

Note : If i send the disconnect command from the MCP to the nRf application, it disconnect soon.

Regards, Anand