https://devzone.nordicsemi.com/f/nordic-q-a/115275/the-mysterious-led5-on-the-nrf52840-dk-what-does-it-indicateHi, Can you tell me what LED5 on the nrf52840 DK indicates? When is it on? When is it off? 2 observations I have made: When the DK is connected to a development computer USB port and it is running a flashed program, LED5 is on almost continuouslyen-USTelligent Community 13Sat, 12 Oct 2024 23:45:47 GMThttps://devzone.nordicsemi.com/thread/505984?ContentTypeID=1Sat, 12 Oct 2024 23:45:47 GMT137ad170-7792-4731-bb38-c0d22fbe4515:692b53d8-a5b8-4098-9bc3-41c896fdc912Ken58<p>Thank you very much Bendik!</p> <p>Ken</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/505216?ContentTypeID=1Mon, 07 Oct 2024 14:37:44 GMT137ad170-7792-4731-bb38-c0d22fbe4515:05d4052d-308d-44d0-a73d-ff2ec173da9dBendik Heiskel<p>Hi Ken,</p> <p>LED5 is controlled by the interface MCU(IMCU). It indicates three states of the IMCU:</p> <ol> <li>Constant rapid blinking, indicates 5V on the VBUS pin(of the IMCU) but the device is not enumerated by the computer. This is mainly an issue when a faulty or charging only USB cable is used.</li> <li>Continuously on, the IMCU is connected to the computer and enumerated, but theres no traffic on the SWD lines.</li> <li>&quot;Random&quot; blinking, traffic on the SWD lines, when programming or debugging.</li> </ol> <p>&nbsp;</p> <p>Best regards,</p> <p>Bendik</p><div style="clear:both;"></div>