hevans1944
Hop - AC8NS
It appears that a lot of folks who "play" with Arduinos leave them tethered to a PC for convenience, as well as for accessibility to a keyboard, mouse and video display. This isn't necessary if the Arduino application software (the sketch) provides support for human interaction through ports on the Arduino. However, the OP does not appear to have the qualifications necessary to write sketches for stand-alone Arduino projects, nor the qualifications necessary to design and implement the HMI (human-machine interface).
For example, if a stepper motor is to used, presumably attached (somehow) to the tuning capacitor, there needs to be a motor driver shield and at least one toggle switch with a center-off position to select UP and DOWN tuning direction. As somebody here (besides me) has noted, this is NOT a teaching forum. The OP would need to develop Arduino programming skills and become familiar with how to perform simple switch I/O operations, including switch de-bouncing either in software or in hardware. A true hobbyist devours these simple procedures and moves on to bigger and better projects, coming back to EP to share their experience, or to ask targeted questions aimed at specific difficulties they have encountered. This usually results in a useful dialog that benefits everyone involved.
A side note on varicaps versus motor-driven tuning capacitors: I like the idea of motor-driven tuning, although perhaps with a PWM-driven PMDC motor instead of a stepper motor for smoother operation. Also much simpler to implement. And I wonder if it wouldn't be possible to make a DIY voltage-tuned capacitor by using a compliant foam insulation between parallel plates and then adjusting the plate separation by varying the DC bias voltage applied to the plates? Might need a few hundred volts to get a useful change in capacitance, depending on foam compliance and plate area, but it should be something a DIYer can accomplish.
For example, if a stepper motor is to used, presumably attached (somehow) to the tuning capacitor, there needs to be a motor driver shield and at least one toggle switch with a center-off position to select UP and DOWN tuning direction. As somebody here (besides me) has noted, this is NOT a teaching forum. The OP would need to develop Arduino programming skills and become familiar with how to perform simple switch I/O operations, including switch de-bouncing either in software or in hardware. A true hobbyist devours these simple procedures and moves on to bigger and better projects, coming back to EP to share their experience, or to ask targeted questions aimed at specific difficulties they have encountered. This usually results in a useful dialog that benefits everyone involved.
A side note on varicaps versus motor-driven tuning capacitors: I like the idea of motor-driven tuning, although perhaps with a PWM-driven PMDC motor instead of a stepper motor for smoother operation. Also much simpler to implement. And I wonder if it wouldn't be possible to make a DIY voltage-tuned capacitor by using a compliant foam insulation between parallel plates and then adjusting the plate separation by varying the DC bias voltage applied to the plates? Might need a few hundred volts to get a useful change in capacitance, depending on foam compliance and plate area, but it should be something a DIYer can accomplish.