https://devzone.nordicsemi.com/f/nordic-q-a/1163/android-4-3-galaxy-s4-connection-disconnect-automaticallyI was using nRF Master Controller app on Samsung S4 to connect to my Ble device. However, after connected a while, the device will be disconnected automatically while I was doing nothing just putting the phone and the device aside.en-USTelligent Community 13Fri, 20 Dec 2013 03:36:47 GMThttps://devzone.nordicsemi.com/thread/5448?ContentTypeID=1Fri, 20 Dec 2013 03:36:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:863ac6b0-0f3a-4670-93cd-87598c01f8e6linkQ<p>Thank you very much for your reply. I am using S4 with android 4.3. I will modify the connection interval later to see if it will work. I think this is where the problem is.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/5447?ContentTypeID=1Thu, 19 Dec 2013 15:08:20 GMT137ad170-7792-4731-bb38-c0d22fbe4515:23771ab3-eba9-49bd-b2f0-0d1198b9d1d4Hung Bui<p>Hi LinkQ,</p> <p>Which Android version does your S4 have ? On Andorid 4.3, the minimum connection interval that S4 accepts is 37.5ms. If you have your prefered connection parameter that have minimum connection interval &lt;30ms and/or max connection interval &lt;40ms, the connection paramater request from the nRF51822 will be rejected by the phone.</p> <p>After 3 requests without success, the nRF51822 will automatically disconnect.</p><div style="clear:both;"></div>