I have a built a fish tank LED lighting system which is run via 7 PWM channels of my Arduino Mega via an app called Blynk on a Samsung tablet.
I have sliders on the app which adjust each of 7 variables from 0-255. I would like to add a 'master' slider which will increase or decrease whatever the individual variables are proportionately. I can't however figure out the maths/algorithm.
Can anyone help on how I can make this happen?