changing those values would change the limits of the gFilterFrequency
variable, but nothing is going to be output through the analog outputs. You'll need a line such as
analogWrite(context, frame, channel, value);
and value should be comprised between 0
(corresponding to 0V) and 1
(corresponding to 5V). Now, I could give you the answer to do what you are asking in your initial post, but my understanding is that you are here to learn, so I'll leave it to you as an exercise, unless you tell me otherwise.
InesL 2) My point is to easily be able to change the duration of the signals and starting time.
what do you mean "the starting time"? Do you want the ramps to start in reaction to an external trigger?