I want to implement a digital controller C(z) on an Arduino Uno (transfer function in the z domain) in order to control a plant
G(s) = 3750/[(s+10)(s+30)(s+100)].
I have implemented G(s) with electronics (op-amps, capacitors and
resistances). I want to realize C(z) on the Arduino Uno. The input to
the Arduino is the error signal
(reference − output of G) and the
output of C(z) is the input of G(s). Finally, I will have a closed loop
system with negative unit feedback. The reference input is a unit step
signal (1 volt).
My problem is: how can I use PWM and filters in place of a DAC?