Ramping Down the variable in Arduino IDE with the help of millis()??......

David_ZI:
When the variable is at 3.30, i want to ramp it down again to 0.01.

Probably with something like this

define a variable

float setPointAdj = 0.1

change your code roughly like this

setPoint = setPoint + setPointAdj;
if (setPoint >= 3.3) {
   setPointAdj = -0.1
}

...R