PiHPSDR is software designed to run on the Raspberry Pi using the official 7 inch touch screen. It can be compiled to include support for Rotary Encoders and Push Buttons using the GPIO pins and/or the i2c interface.
It can be compiled and run on most Linux and Apple Mac systems without using GPIO.
It is recommended to use a Raspberry Pi 4 with 4GB or 8GB of memory if running Ubuntu 64bit OS. The 2GB version will work OK using the Raspberry Pi 32 bit OS.