I just got a new motorized slide pot. http://www.sparkfun.com/products/10976
It has two output signal but I don't see how this could not just be one since the reading is the same. (I guess for analog sound etc.?)
The potentiometer is equipped with a small DC motor.
I need to be able to stop the motor, corresponding to precise desired values of the potentiometer.
So far I have only been able to find out about direction and speed control of a motor. This however is not enough.
Since a servo does exactly what I need, very easely, and the thing that enables a servo to do just that, is the fact that there is a potentiometer attached to it, I guess this is the type of controller I need to get or make.
In order to learn, I find it a bad solution to just scavenge a controller from a servo. It must be possible with some chip and some wire and other simple components.
What i need is a way to turn my DC motor, with a feedback potentiometer already attached, into a complete servo.
When i search for these controllers and how to make them i find one of two things:
1. A controller to control a servo. This requires the servo to all ready have a "servo-controller" on board,
and only controls the, all ready finished, servo.
2. A motor-controller. This only allows for direction and speed control. (or does it?)
I have been reading ALOT of forums and googled the web thin to find a good way to control the motor but it only leaves more questions:
Will a h-bridge do that?
Will a 555-timer do that?
Will a L293 do that?
Will a PID do that and if so... is there any way to buy a finishedand adjustable PID network? (I find them quite complicated)
Could it be done with direction control and some code that would not take up all of the chip-storage?
something like "if desired_value > actual_value, drive motor one way
if desired_value = actual_value, do nothing
if desired_value < actual_value, drive motor the other way"
The problem with this kind of logic, the way I see it, still is that the motor would not know when to stop.
This could be done by saying that the motor should drive for a specific short amount of time, and then rely on the loop to
eventually get the fader button to its destination. That would however slow down the rest of the sketch and I guess it would
also make the fader button move in a "stuttery" way.
How can I get the complete control of this motorized slide potentiometer and how do i hook-up the solution?
Please help me! I have really done everything i could to find out on my own before asking here. If this helps me on my way, I will eventually post a complete description on how to do this, since I cant be the only one.