The onboard interface MCU features a Universal Asynchronous Receiver/Transmitter (UART) interface through a virtual serial port.
The virtual serial port has the following features:
- Flexible baud rate setting up to 1 MbpsNote: Baud rate 921 600 is not supported through the virtual serial port.
- Dynamic Hardware Flow Control (HWFC) handling
- Tri-stated UART lines when no terminal is connected
The following table shows an overview of the UART connections on the nRF52840 System on Chip (SoC) and the interface MCU.
| nRF52840 GPIO | 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 serial port on the computer.
Note: The terminal software used must send a Data Terminal Ready (DTR) signal to configure the UART interface MCU pins.
P0.05 (Request to Send (RTS)) and P0.07 (Clear to Send (CTS)) can be used for other purposes when HWFC is disabled on the nRF52840 SoC.