nRF52840 Preview DK v0.9.x

Virtual COM port

The on-board interface MCU features a UART interface through a virtual COM port.

The virtual COM port has the following features:

Table 1 shows an overview of the UART connections on nRF52840 and the interface MCU.

Table 1. Relationship of UART connections on nRF52840 and interface MCU
GPIO nRF52840 nRF52840 UART
P0.05 RTS
P0.06 TXD
P0.07 CTS
P0.08 RXD

The UART signals are routed directly to the interface MCU. The UART pins connected to the interface MCU are tri-stated when no terminal is connected to the virtual COM port on the computer.

Important: The terminal software used must send a DTR signal in order to configure the UART interface MCU pins.

The P0.05 (RTS) and P0.07 (CTS) can be used freely when HWFC is disabled on the SoC.

Important: The mbed OB interface does not support HWFC through the virtual COM port.
1 Baud rate 921 600 is not supported through the virtual COM port.