https://devzone.nordicsemi.com/f/nordic-q-a/14394/dfu-using-uartHi. PCA10028, SDK10.0.0, S130. I&#39;m testing DFU using UART not BLE. How can i edit UART Tx,Rx pin number? When I download &quot;dfu_dual_bank_ble_s130_pca10028.hex&quot; using nRFgo Studio, LED1,3 is always ON, whether I push button4 or noten-USTelligent Community 13Fri, 17 Jun 2016 08:05:42 GMThttps://devzone.nordicsemi.com/thread/54961?ContentTypeID=1Fri, 17 Jun 2016 08:05:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:21e300ac-c500-4ad3-90e9-c0246d251023roger.k<p>Thanks. Let me just try.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/54960?ContentTypeID=1Wed, 15 Jun 2016 10:59:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:0914d318-8133-42de-953d-94d482fd20c5Stefan Birnir Sverrisson<p>Hi Roger</p> <ol> <li> <p>I suspect you configure the UART pin assignment of the HCI bootloader in the \nRF51_SDK_10.0.0_dc26b5e\examples\dfu\bootloader\config\dfu_single_bank_serial_s130_pca10028\hci_transport_config.h file.</p> </li> <li> <p><a href="http://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v11.0.0/bledfu_example_running.html?cp=5_0_0_4_3_1_1_0">LED 3 on means that the device is in bootloader mode</a>. LED 1 on means that the device is advertising. Button 4 will not do anything when application is not uploaded to the device. Once an application has been uploaded to the device, it will start the application when you reset the board, unless you press and hold button 4 while you reset, then the device will start up in bootloader mode.</p> </li> </ol><div style="clear:both;"></div>