Getting the Gauges to work

We are now working on getting the Gauges of the Renault to work.
They are all electronic based (no mechanics) so we are trying to get them to work using their own electronics before taking them apart and brutally adding servos inside...
This will be more elegant way and should imitate the real thing accurately.
We found out that the gauges change based on PWM - Pulse Width Modulation
Now we are looking to buy a controller to generate the PWM for the gauges based on the software variables.