Quantity   Component name
1 × Arduino Uno
1 × TMC2130 Stepper driver. It comes in many flavors, chose one that doesn't have headers pins on top if you want to use my enclosure
1 × Arduino Proto Shield The type of proto shield you can see in the photos. Preferably without the top header pins soldered
1 × Nema 17 stepper motor, model 17HS4023 Any model will work, but you'll have to adjust STALL_VALUE in code
2 × 3.5 audio jack with 4 poles If you want to use my enclosure, make sure they have a smaller diameter then 8.5mm and can be screwed. I ordered these ones: https://www.aliexpress.com/item/1005001463811799.html?spm=a2g0o.9042311.0.0.a18c4c4dotEFwl
1 × Flexible coupling To connect the stepper to your variable capacitor. Nema17 shaft is 5mm, so chose one 5mm to your variable capacitor shaft size. I ordered from here: https://www.aliexpress.com/item/32874492868.html?spm=a2g0o.9042311.0.0.58c64c4dXIRmXu