So when the "selector" is advanced, you give a little stab to raise the wing.
When the selector is clocked the other way, a little stab to lower it.
This doesn't seem like it would work very well without any feedback.
First, you would have to bring the system up with the wing in a known position.
Halfway maybe.
Next, you'd need to have the rotary switch in the correct corresponding position at boot/reset time.
Call that 2, from 0, 1, 2, 3 and 4 as positions.
Now the fun begins. If the scootches are accurate (repeatable), you can select back and forth meaningfully.
If they are not consistent and identical, how long will it work before returning to 2 no longer places the wing at the middle?
I would not rely on that working very well, position feedback would be the solution.
But you may have a very nice actuator that does take a timed pulse and move a very certain distance, regardless of all variables - load, supply voltage, friction and so forth.
Yeah I've been pondering this. There are affordable linear actuators that are advertised with internal limit switches. What are the merits of using one as a datum?
lets say we start the car. Arduino powers on waits for signal to run script. driver initiates script. As the driver runs the pilot checklist, the switch it toggled to the 0, or lowest position. the code is structured in such a way that when it reads the rotary switch moves from position 1 to position 0 it sends an extended pulse, only slightly longer than the regular position change pulse to physically retract the actuator all the way to its onboard limit switch. Then the Arduino is scripted to reset itself(mabey?) and now we have switch and actuator at lowest physical position/selection to then work from. Repeatability of linear travel during regular 'selection pulse' will need to be tested with a physical unit to know with what frequency a return to zero is needed.
Yes, using the limit switch to calibrate the mechanism would work, and the idea of doing that automagically when the selector is at 0 is a good idea.
If the limit switch is more a safety thing, not meant to be accurate necessarily, that would not work, depending on how very accurate it needed to be.
It seems like only when the system is fully up will you be able to see if it will work out.
The repeatability and need for re-calibration.
Are there not linear actuators that operate like servos, that is that they have a controller and feedback mechanism included, and could be driven like any little r/c servo using the servo library?
There are some with feed back available but they increase in cost 3x.... a linear actuator with a 4" stroke and 160lbs holding force is $50 on amazon, a 6" stroke and 150lbs with feedback is $150 on amazon.... that's a little out of budget these days.
