USB to serial cable allows connection to Raspberry Pi (UniPi) without the need of SSH or Display+Keyboard. UniPi serial adapter manual:
Simply connect this to your computer’s USB port and to RJ11 connector of UniPi’s UART and use Putty(Windows), screen(linux) for serial communication.
Set the baud rate is 115200,
UniPi serial adapter Compatible with Windows (CE, XP, 2003, Vista, 7), Linux and Mac.
sudo screen /dev/ttyUSB0 115200
We recommend using Putty for communication. Open putty, choose Serial connection type, your COMx port (where x is the number of the port – right click on This Computer -> Properities -> Device Manager -> Ports (COM & LPT) -> Profilic USB COMx) and set the speed to 115200 and hit Open.