https://devzone.nordicsemi.com/f/nordic-q-a/70295/usb-cdc-acm-driver-dependency-on-dtrHi Using demo usbd_cdc_acm and found a very strange bug! Even I disabled the flow control of uart , the 52840 device still need to control the DTR signal to ensure UART communiction. Did anyone else found this issue?en-USTelligent Community 13Sun, 10 Jan 2021 11:20:30 GMThttps://devzone.nordicsemi.com/thread/288274?ContentTypeID=1Sun, 10 Jan 2021 11:20:30 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a8bcd595-4fdb-4066-b388-c09bcb7e267eDmitry<p>Hi,</p> <p>DTR is not related to flow control, CDC ACM requires it to be high to enable communication. See also <a href="https://devzone.nordicsemi.com/f/nordic-q-a/28107/nrf52-dk---usb-cdc-acm-example-not-working-with-hterm-qt">this</a> answer.</p><div style="clear:both;"></div>