https://test-devzone.nordicsemi.com/f/nordic-q-a/88919/nrf52840-sdk-16-0-1-windows-10-usb-only-can-be-written-but-not-be-read-could-you-help-me-check-out-how-to-adjust-the-deviceIn the nRF52840, I used the app_usbd_cdc_acm_write(&amp;m_app_cdc_acm,tx_buf,size) method to output the data. At the beginning, I use the pyserial to read the output data from the COM port. It works, but the speed of serial is a little bit slow arounden-USTelligent Community 13 Non-ProductionTue, 14 Jun 2022 08:37:41 GMThttps://test-devzone.nordicsemi.com/thread/372312?ContentTypeID=1Tue, 14 Jun 2022 08:37:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:3c2c9b59-8e54-4259-b911-5c0690166605user15146<p>Hi,</p> <p>I have a BLE central version of the usbd_ble_uart example here you can have a look at:</p> <p><br /><a href="https://test-devzone.nordicsemi.com/f/nordic-q-a/88469/usbd-ble-uart-central-com-port-not-visible/370772#370772">https://devzone.nordicsemi.com/f/nordic-q-a/88469/usbd-ble-uart-central-com-port-not-visible/370772#370772</a></p><div style="clear:both;"></div>https://test-devzone.nordicsemi.com/thread/372260?ContentTypeID=1Tue, 14 Jun 2022 06:15:33 GMT137ad170-7792-4731-bb38-c0d22fbe4515:adaac8d4-1626-45b3-8cd6-6d9addb90e67user116923<p>Also, in my project, the device firstly receive the data from the other device through BLE. Then, the device use usb to output the data into the computer.</p><div style="clear:both;"></div>https://test-devzone.nordicsemi.com/thread/372248?ContentTypeID=1Tue, 14 Jun 2022 02:32:58 GMT137ad170-7792-4731-bb38-c0d22fbe4515:59e679d3-196b-4d7b-bc4b-dd1bbd04959euser116923<p>This is the USBTimeoutError.</p> <p><img src="https://test-devzone.nordicsemi.com/resized-image/__size/640x480/__key/communityserver-discussions-components-files/4/pastedimage1655173946076v1.png" alt=" " /></p><div style="clear:both;"></div>