^ I wouldn't say genius. I'm always asking questions for help here - it just happens that I already went through something similar to you.
The controller you linked would be more suitable if you already had a microcontroller for your project and needed something to drive the motor.
The way I used mine is as follows, and sounds very similar to what you're doing:
- My input was a pot from a joystick. It was connected to GND, +5V (from the controller) and the wiper was the input to the Pololu.
- My output was a 12V DC motor connected to a lever through gear reduction. It was spring loaded to return if motor power was cut.
- On my lever I mounted a second pot to measure the position of the lever. My lever moved 90 degrees and I centred the pot so that 45 degrees was exactly midpoint of the pots travel. It was connected to the feedback connector on the Pololu (GND, +5V and the wiper to Feedback).
- When you first configure the Pololu you have to calibrate your input & output pots. You do this by clicking "Learn" on the Input and Feedback tabs of the configuration utility and following the instructions (it involves moving them to their maximum positions and clicking on OK so the Pololu can learn the positions).
- Then it's as simple as powering up your Pololu and testing it. I had mine literally working in under 5 minutes.
- This is a servo system, so the controller is always trying to move the motor (and your lever) so the voltage output of the feedback pot matches the voltage from your input pot. In other words, the output lever will always match the input pot.
- The motor current (and therefore speed) will be proportional to the difference between the input and feedback. In other words, if you quickly press the input "throttle" to maximum, then the motor will get maximum current to try and move your lever (and feedback pot) as quickly as possible. As your lever (and feedback pot) gets close to its target, motor current is reduced until just enough current is provided to hold the motor in the proper position.
A few tips that I learned that weren't 100% obvious in the manual.
- Make sure you know which way your motor turns. The positive side of the motor needs to go to output A of the Pololu for Forward movement.
- Make sure that the voltage output of your feedback pot
increases with forward motor movement.
- On the Input tab of the configuration utility, turn off the "Asymmetric" check box. If this is on, the default position for your lever will be in the middle and not at the beginning.
- When calibrating (learning) the feedback pot, make sure the motor is dis-connected. It's in the manual, but it's a very good thing to remember.
- Read the manual. There's a lot to go through, but it's not very complex or hard - but you do need to read everything to make sure you understand how it works (except the section on serial commands, since you won't be using them).