USB-UART bridge

The USB-UART bridge acts as a serial adapter, exposing 2 UART pairs to a USB host as 2 CDC ACM devices.


This sample has been enhanced by the Connectivity bridge application, and is planned to be removed in the future.


The sample supports the following nRF52840-based device:

Hardware platforms


Board name

Build target





The sample also requires a USB host which can communicate with CDC ACM devices, like a Windows or Linux PC.

Building and running

This sample can be found under samples/usb/usb_uart_bridge in the nRF Connect SDK folder structure.

See Building and programming a sample application for information about how to build and program the application.


After programming the sample to your board, test it by performing the following steps:

  1. Connect the board to the host via a USB cable

  2. Observe that the CDC ACM devices enumerate on the USB host (Typically COM ports on Windows, /dev/tty* on Linux)

  3. Use a serial client on the USB host to communicate over the board’s UART pins


This sample uses the following Zephyr subsystems: