Problem in Code porting from nrf51 to nrf52: nrf52 automatically disconnects after few seconds

[Anjali]

hello,

I had written a custom application based on ble_app_uart for nrf51, which works fine. But now I have to port it for nrf52. So I followed these steps:

1. Changed the linker script for nrf52.
2. Changed CFLAGS and ASMFLAGS in makefile for nrf52.
3. use softdevice 132, include headers from s132.
4. use s132 hex file for flashing

But after ble advertising, if a connection from android app is successful it lasts only for a few seconds and then disconnects. edit: There is no such code in neither custom application nor sample application which I modified in order to disconnect from android app. I am not able to figure out what is causing this problem. Please help. Edit: Now I also modified the sdk_config.h file according to nrf52 definitions. But I haven't observed any change in this behaviour

Edit: I am using SDK 12.1.0 and s132 v3

[Anjali]

I had forgotten to replace the startup files of nrf51, which I have done currently. After these changes, I am observing desired output, but it is not consistent. My device is still getting discoonected a lot of times. As you suggested, if I find out the reason of disconnection, it shows:

BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION

And I am not able to see the prints from NRF_LOG_ERROR. I referred the post from:

devzone.nordicsemi.com/.../

But I did not see any logs