https://devzone.nordicsemi.com/f/nordic-q-a/42711/bluetooth-can-not-connectHi, I run the demo program &quot;ble_app_hrs_freertos&quot; and the ble can advertise, and my phone can find the device,but can not connect to it. When I run demo program &quot;ble_app_blinky&quot; it&#39;s all ok. I think there is something wrong with these macors valueen-USTelligent Community 13Mon, 21 Jan 2019 10:43:30 GMThttps://devzone.nordicsemi.com/thread/166787?ContentTypeID=1Mon, 21 Jan 2019 10:43:30 GMT137ad170-7792-4731-bb38-c0d22fbe4515:ef42f0d3-70c2-4b7e-8aaa-4e6216470fa3Susheel Nuguru<p>Please go through <a href="https://devzone.nordicsemi.com/f/nordic-q-a/41386/guide-to-allocate-the-amount-of-ram-rom-i-need">this </a>post to understand the meaning of those macros in your memory section placements file. The ble_app_hrs_freertos example unedited should run and connect fine out of the box.</p> <p>The Flash start address and size looks fine for the softdevice, but i am not sure about the RAM START and its size. Ifyou have UART or RTT logging, it will tell you to correct the RAM value based on the attribute size you have.</p><div style="clear:both;"></div>