Well written code, so what is next task

I need to decide how to use a mechanism to unhinge the slingshot cord via servo

Where are we on this steve? About the slingshot, could you please share some more info on what it would be used for so that a correct mechanism could be devised for the release of the slingshot?

So very very lightweight slingshot, It could be powered via rubber band (all I want to do is launch paper balls).

Any solution is valid as long as it meets that weight criteria and can be launched via servo motor.

Well i have an idea, make it like a trebuchet,as used in old time to throw heavy stone in wars. You can load it with paper ball, pull rubber band elongate it using servo then release servo in order to fire.

temporarily paused this to work on Hacking The Mixpanel API with Arduino UNO