a ardiuno nano/mega i have bothWhat circuit board are you connecting it to?
i can use another one if you have a better recommandationSorry, not sure about arduino.
absoluteJust to make sure – Do you want a rotary switch with absolute positions, or a rotary encoder for incremental inputs?
i dont understand?With a rotary switch you will need to add series resistors to build a resistor ladder which adds/subtracts for each click. The Leo Bodnar £5 3 wire ones are a good base point if you don’t want to do this yourself (1k resistors linked between each pole is fine)
apply your 5v and ground lines and read the output voltage from the voltage divider you have just created.
write the step voltages down (they should be more or less the same but will differ within the resistor tolerance bands)
in your arduino sketch you can then either use a linear equation with nearest integer rounding, an array or a lookup table to output your switch position from the analogue voltage reading.
If you get stuck there is plenty of walk throughs on the likes of instrucables by searching “Arduino Rotary Switch”