The Wiremod add-in for Garry's Mod does, alongside with programmable chips and all sorts of neat stuff... although having a look (it has been a number of years.

The Wiremod add-in for Garry's Mod does, alongside with programmable chips and all sorts of neat stuff... although having a look (it has been a number of years...) the PID controller was in the "extras" extension to Wiremod.