I was looking for a long range system to allow me to communicate with the Raspberry Pi and came across a USB radio system using LPRS EasyRadio. Each unit cost about £40, but offered an easy communication system over a longer range than WiFi. The system I purchased was the Easyradio USB Connect-2-Pi Dongle 900MHz version, designed to work with the Pi, but arrived with no documentation at all.
Full details for the setup are given in the setup sheet, and in less than 10 minutes I had it all working. I ran the downloaded Python script and sent the command ER_CMD#TR and received a reply from the radio showing the modules firmware revision number.
The next job is to get the radio working on the PC.