Connecting to a PI Zero via UART is, in my opinion, a much cleaner way of interfacing with a Raspberry Pi. All you need is: laptop to UART to Pi.
What is UART?
Universal Asynchronous Receiver-Transmitter – A UART is either; an individual unit or a part of a larger integrated circuit used for serial communication. This piece of gear is used to bridge from PuTTY (Windows) or a Unix command line TTY directly to the target device via a serial connection, in this case to a Raspberry Pi Zero.
To connect to the pi we will only need to worry about 4 of these UART pins:
RXD – Receive Data | TXD – Transmit Data | 5V – 5 Volt power | GND – Ground
Here you can see multiple Grounds and 5V, feel free to use any of those to connect to the UART.
Pin 8 you can see is GPIO14-UART0_TXD that is our UART TXD port. Connect this to the UARTS RXD port (notice that TXD and RXD are crossed over).
Pin 10 is GPIO15-UART0_RXD that is our UART RXD port. Connect this to the UARTS TXD port.
Connect these and plug the UART to a USB port on your Ubuntu machine then run dmesg and check the serial connection has been detected and assigned a tty.
The dmesg output should look something like the following:
Now that we have an assigned tty we can use screen to connect to the serial device using the baud rate of 115200 using the following command:
sudo screen /dev/ttyUSB0 115200
And now you’re ready to go!