[seiferteric]

In lieu of my final in control systems class, the professor allowed anyone to make a PID controller and present it to the class instead. All the EEs went this route (seems unfair to the others in retrospect LOL) and it was a great experience. Many did it digitally, but I opted for purely analog with op-amps for P, I and D with a summing op amp circuit at the end. This was connected to a pair of power transistors to drive a DC motor (from my lego mindstorm) and some gears to move a stick on a board. The input was a potentiometer with a nice metal knob. Each of the PID also had a pot to control it's own amplification before going into the summing circuit so you could adjust and see the behavior of each element. This was one of the most rewarding projects I have ever done I think, so cool to see it in action.

[deadso]

Reminds me of this project from MIT students where they built an analog Segway:

https://techtv.mit.edu/videos/687f4627e5c14a52b24c694f7eeecf...

[jcims]

That's amazing, something very legit about the analog approach and I can imagine it was pretty thrilling to see it actually work.