The interface MCU features a Universal Asynchronous Receiver/Transmitter (UART) interface through a virtual serial port. One port is connected to the physical port on the Development Kit (DK), and the other is not usable.
The following table lists the nRF52832 System on Chip (SoC) UART GPIO pins and their signals.
| GPIO nRF52832 | nRF52832 UART | Interface MCU UART |
|---|---|---|
| P0.05 | RTS | CTS |
| P0.06 | TXD | RXD |
| P0.07 | CTS | RTS |
| P0.08 | RXD | TXD |
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. The terminal software 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.