To connect the Raspberry Pi to a PC via UART, you will need a USB Serial Cable that supports 3.3V.Īs seen on the image above, this cable has four female wires that can be plugged into the Raspberry Pi. Connecting a Raspberry Pi to PC using UART
Generally, the PL011 UART is more reliable than the mini UART because the latter has smaller FIFOs, lacks flow control and has its baud rate reliant on the VPU clock speed. Each UART can be accessed individually via /dev/ttyS0 for the mini UART and /dev/ttyAMA0 for the PL011 UART. Whichever UART is assigned to the Linux console is accessible through /dev/serial0. For these models, the PL011 UART is tied directly to the Bluetooth module. On the other hand, the mini UART becomes the Linux console UART for models with Bluetooth like the Raspberry Pi 3 and Raspberry Pi Zero W. This means you can send Linux commands from your PC to the Raspberry Pi on this UART. The PL011 UART is the main UART for models without Bluetooth feature and is tied directly to the Linux console output. However, you only have one pair of TXD and RXD pins to work with.
Technically, the Raspberry Pi has two UARTs: PL011 UART and mini UART. Note that these pins use 3.3V logic levels so you can’t connect them directly to devices that uses 5V like an Arduino UNO or a PC. The Raspberry Pi UART transmit (TXD) and receive (RXD) pins are assigned to GPIO14 and GPIO15 respectively: Introduction to Raspberry Pi Serial Ports
