https://devzone.nordicsemi.com/f/nordic-q-a/15236/undefined-symbol-from-device-managerI encountered the following error while adding device manager to ble_uart_app in SDK_11 s130 using the hardware nrf51-DK. I&#39;m using Keil compiler. ._build\nrf51422_xxac_s130.axf: Error: L6218E: Undefined symbol dm_init (referred from main.o).en-USTelligent Community 13Wed, 20 Jul 2016 11:10:40 GMThttps://devzone.nordicsemi.com/thread/58175?ContentTypeID=1Wed, 20 Jul 2016 11:10:40 GMT137ad170-7792-4731-bb38-c0d22fbe4515:537b75e9-01e2-4778-b4f1-9111485b7606Petter Myhre<p>Thank you for answering your own question.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/58174?ContentTypeID=1Wed, 20 Jul 2016 07:59:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:896bee38-44eb-4c07-9427-1a4bf30a4daehelpme<p>I found this link <a href="https://devzone.nordicsemi.com/tutorials/15/">devzone.nordicsemi.com/.../</a></p> <p>Following the instructions will solve the problem. Add device_manager_peripheral.c to the project, not device_manager_central.c.</p><div style="clear:both;"></div>