This is my latest little homebrew project; a tuning knob unit for my SDRPlay RSP1A software defined radio receiver. The project was inspired by the article "Wireless Tuning Knob" in the April 2018 issue of the excellent Practical Wireless magazine.
To make an easy to use tuning knob for your SDR receiver, the PW article suggests using the inners of a cheap wireless computer mouse, removing the mouse wheel, and connecting a rotary encoder instead. Then a tuning knob can be attached to the rotary encoder's shaft, and voila!
And that's exactly what I did, except I did use a wired USB mouse, not a wireless one, as I didn't want the hassle of having to change batteries all the time. The result is shown in the photos below. It works like a charm!