I am trying to use a micro to control a pump and I intend to use a PID controller for this. Here is what I have
- I have a target set point pressure (units PSI, bar or mmHg)
- From the micro, I drive the pump with a pwm (duty cycle , units %)
- The micro reads an AD voltage signal which is proportional to the pressure (units Volts)
INPUT ---+--Err->-(SYSTEM)-----+--------OUTPUT | | | | | | ---------------------------------
So my input is 1 (units pressure), which is somehow translated to 2. (units % duty cycle), the output is a pressure which is read as a voltage.
My confusion is how I resolve all these different units?
I am sure this is commonplace - how is it done?
Thanks!! Liam