https://devzone.nordicsemi.com/f/nordic-q-a/58831/android-application-developmentHi, We are developing an android application using nRF51422 to connect the BLE device, discovering characteristics and sending commands to the device. Here we are facing following difficulties. 1. Sometimes the nordic board is refusing to connecten-USTelligent Community 13Tue, 14 Apr 2020 06:29:35 GMThttps://devzone.nordicsemi.com/thread/244319?ContentTypeID=1Tue, 14 Apr 2020 06:29:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:749584e7-abb9-4423-9f1e-15714f11177aSigurd[quote user="Prithwi Chanda"]I am worried about when it stops responding suddenly. That is the reason why it is not connecting or suddenly getting disconnected.[/quote] <p>As mentioned, this could happen if e.g. the device lost power, or if there was an assert in the code. You will likely need to do some debugging to find the root cause . Maybe some error-code was returned somewhere ? Take a look at e.g. this post <a href="https://devzone.nordicsemi.com/f/nordic-q-a/10729/my-device-is-freezing-and-restarting">https://devzone.nordicsemi.com/f/nordic-q-a/10729/my-device-is-freezing-and-restarting</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/243779?ContentTypeID=1Tue, 07 Apr 2020 04:31:00 GMT137ad170-7792-4731-bb38-c0d22fbe4515:d995bbc7-762c-4814-b7bd-7c8188ba8ff0Prithwi Chanda<p>Master is sending&nbsp;<span>LL_TERMINATE_IND packet when disconnection is done intentionally using the disconnect button. I m not worried about that. I am worried about when it stops responding suddenly. That is the reason why it is not connecting or suddenly getting disconnected.</span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/243720?ContentTypeID=1Mon, 06 Apr 2020 14:50:03 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8f9ca843-ec52-4606-bd71-ef2a532ba08eSigurd<p>In the log report7.pcapng, we see the master/phone sends an LL_TERMINATE_IND packet. It’s not clear from the log why the master terminates the connection. If you use nRF-Connect for mobile app, the log there might reveal more information about why the phone disconnected.</p> <p>In report13.pcapng, it seems like the slave suddenly stopped responding. This could happen if e.g. the device lost power, or if there was an assert in the code. You will likely need to do some debugging to find the root cause here. If you enable logging in the code, then nrf_log outputted over UART or Segger RTT, could provide you with some clues about what happened.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/242935?ContentTypeID=1Wed, 01 Apr 2020 11:47:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f6b2bdbb-3c8f-402b-8405-54d2fdc76da1Prithwi Chanda<p>Hi, is there any update?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/242329?ContentTypeID=1Mon, 30 Mar 2020 09:08:48 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6ec260e7-1360-4ef1-9a21-035f77e484fePrithwi Chanda<p>Right now I have found one more issue like,&nbsp;</p> <p><span>-&nbsp; Once devices are connected it is expected to send Empty PDU to both sides.</span></p> <p><span>- Some time slave is not sending Empty PDU and causing disconnection.</span></p> <p><span>In bellow image, we can see the highlighted area and wireshark logs also attached</span></p> <p><span><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1585559291223v1.png" alt=" " /><a href="https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/report13.pcapng">devzone.nordicsemi.com/.../report13.pcapng</a></span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/242279?ContentTypeID=1Mon, 30 Mar 2020 05:19:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:5260194f-4206-4c5c-a36e-10024f9a2bc1Prithwi Chanda<p>1. SDK version:- 11 SoftDevice version:- 130</p> <p>2. I have used Redmi Note 6 pro(Android 9), Moto G4 plus(Android 7), Samsung A107F<span>(Android 9)</span></p> <p>3. Yes I have faced same issue in nRF-Connect for mobile too</p> <p>4. Wireshark log is attached bellow.</p> <p><a href="https://devzone.nordicsemi.com/cfs-file/__key/communityserver-discussions-components-files/4/report7.pcapng">devzone.nordicsemi.com/.../report7.pcapng</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/242068?ContentTypeID=1Fri, 27 Mar 2020 10:43:44 GMT137ad170-7792-4731-bb38-c0d22fbe4515:74572e57-1c4a-4f6d-a536-7be126740947Sigurd<p>What SDK version and SoftDevice version are you using?</p> <p>What phone model and brand are using ?</p> <p>Do you see the same issue when using <a href="https://www.nordicsemi.com/Software-and-tools/Development-Tools/nRF-Connect-for-mobile/GetStarted">nRF-Connect for mobile</a> ?</p> <p>Please upload the wireshark log</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/241380?ContentTypeID=1Tue, 24 Mar 2020 13:05:15 GMT137ad170-7792-4731-bb38-c0d22fbe4515:81769901-a899-4c45-a7db-6e4ced68a87cPrithwi Chanda<p>Hi,</p> <p>I have done debugging using wireshark. there I faced the following issue.</p> <p>When phone is sending LL_FEATURE_REQ packet it expects LL_FETURE_RES in return from the board like this</p> <p><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1585055167370v1.png" alt=" " /></p> <p>But when the nRF board is refusing to response&nbsp;<span>LL_FETURE_RES&nbsp;device is not getting connected with phone like this</span></p> <p><span><img src="https://devzone.nordicsemi.com/resized-image/__size/320x240/__key/communityserver-discussions-components-files/4/pastedimage1585055189417v2.png" alt=" " /></span></p> <p><span></span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/238633?ContentTypeID=1Sat, 07 Mar 2020 10:44:01 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ff99e479-58d6-48fc-b50c-8c6b68c52edeawneil<p>So what <strong>debugging</strong> have <em><strong>you</strong> </em>done to find what&#39;s going on ?</p> <p><a href="https://www.argenox.com/library/bluetooth-low-energy/ultimate-guide-to-debugging-bluetooth-smart-ble-products/">https://www.argenox.com/library/bluetooth-low-energy/ultimate-guide-to-debugging-bluetooth-smart-ble-products/</a></p> <p><a href="https://infocenter.nordicsemi.com/topic/ug_gsg_ses/UG/gsg/debug.html">https://infocenter.nordicsemi.com/topic/ug_gsg_ses/UG/gsg/debug.html</a></p> <p><a href="https://infocenter.nordicsemi.com/topic/ug_gsg_keil/UG/gsg/debug.html">https://infocenter.nordicsemi.com/topic/ug_gsg_keil/UG/gsg/debug.html</a></p> <p><a href="https://www.avrfreaks.net/comment/2418156#comment-2418156">www.avrfreaks.net/.../2418156</a></p> <p></p> [quote userid="88519" url="~/f/nordic-q-a/58831/android-application-development"]the nordic board is refusing to connect[/quote] <p>How do you know it&#39;s specifically the Nordic board?</p><div style="clear:both;"></div>