Math aid Needed: Scaling an Arduino analog input to be -1 to 1

Question

The Arduino map() function does not work for this problem, and HAVE scoured the 'net for examples but am still coming up at a loss. My 'math-brain' is ded!! :-( I have a pot going into an Arduino analog input produces a range of 170 to 1000. I'd like to scale that to a range of -1 to 1 to simulate a commercial joystick that is being replaced. There is an Arduino Micro reading the pots and sending the data by serial to Processing. This all works - just can't get the -1 to 1 range to send out. A formula to do this would be a HUGE help! =Alan R. JavaScript questions and answers, JavaScript questions pdf, JavaScript question bank, JavaScript questions and answers pdf, mcq on JavaScript pdf, JavaScript questions and solutions, JavaScript mcq Test , Interview JavaScript questions, JavaScript Questions for Interview, JavaScript MCQ (Multiple Choice Questions)

Answer 1

You can use linear interpolation to do the magic. If x is the input and y is your desired output, the following relation will work out: (y-1)/(x-1000) = (1-(-1))/(1000-170) = 1/415 So basically, y = 1 + (x-1000)/415