A servo displays measured voltage on a scale.
This is a Project for FRITZING STARTER KIT.
You need a breadboard, an ARDUINO, a servo, a diode, a 1k or 1,1k Resistor and a 100K Resistor. You'll find all this in starter KIT.
Extra you need a printout of a scale and a Pointer. Also you need a double adhesive tape to fix the scale on the servo and also the pointer. Thats it.
I've modivied the arduino example-servo-Knob projekt and instead of using the variable resistor I've build a protection circuit.
All files are included in pointer:instrument.zip
Try it and modify it for yor aim. I'm sure yull have a lot of fun and you'll find a lot of things to indicate it with your New Servo Pointer Instrument
Yours Michael J.