https://devzone.nordicsemi.com/f/nordic-q-a/81848/nrf52840-usbNrf52840 uses usbd_ hid_ The demo of composite is written in sdk15. It can only be recognized by the computer after pressing the restart key or power off for a long time. However, with the demo of sdk17, it can be directly recognized by the computer.en-USTelligent Community 13Thu, 18 Nov 2021 11:57:33 GMThttps://devzone.nordicsemi.com/thread/339610?ContentTypeID=1Thu, 18 Nov 2021 11:57:33 GMT137ad170-7792-4731-bb38-c0d22fbe4515:317c8b9c-1176-45bb-ab07-eecaf85b8af9Kenneth<p>Hello,</p> <p>You are not writing which nRF5 SDK v15.x you are using, but please use nRF5 SDK v15.3 for test and development, I do believe there were some issues on the previous nRF5 SDK v15.x releases that might cause problems.</p> <p>Best regards,<br />Kenneth</p><div style="clear:both;"></div>