My first car was a hand me down Saab and on the side mirror adjustment there was a button you could push that if you were in reverse would make the passenger side mirror angle down and in to view where your rear wheel was, once you either hit the button again or the car was put back into D or P the mirror would resume it's prior position. I want to add a arduino that would do this for me in my new car.
My idea (limited knowledge here so bare with me), I will make an IFTT process string, such as if the toggle is switched to the right w/ the vehicle in reverse the mirror will tilt down, then if the toggle is switched back to the neutral position again or the car was taken out of reverse the mirror would go back.
As far as I see it the hardest part will be setting "points" or position adjustment, mapping each adjustment of the mirror. I don't foresee there being a ton of issues w/ this but I am not sure if I am limited.
Powering the device I think will be east, I will take a splice off of some power behind the dash such as the always hot for the puddle lamps or side turn signal.
If anyone can help me out that would be great! Thanks
Most power mirrors use a human for position feedback. The human pushes controls until the mirror points where they want. That means they typically have no electronic feedback that will let an Arduino know where the mirror is pointed. Without that feedback it will be difficult to have the Arduino point the mirror in any particular direction.
You could use "dead reckoning" where you assume the mirror is in a known position and running the motors for a fixed period of time will move it to the right positions. This tends to fail when power is removed or the voltage fluctuates.
A proper system would require some kind of position feedback from the mirror. Adding position feedback may be easy or hard depending on the existing hardware.
My passenger sideview tilts down to see a curb automatically when put in reverse and tilts back up when out of reverse, no manual input.
But if your car only needs manual button input to start but returns automatically, an Arduino is completely unnecessary.
There will be circuitry already in place to detect shift lever being in reverse, just tie the button to that and be done with it.
As for adjusting the two position limits, read your manual. The car has a learning mode sort of like "when engine off and accessory mode is on, set the mirrors, and then turn on car" etc.
Okay ya I didn't think about there be no feedback on the mirror position, are there any waterproof solutions, obviously not an accelerometer but maybe a gyroscopic sensor w/ feedback along an x and y axis... That would give me both positive and negative positions, and I see no need for a y axis. I mean in theory once the normal and lowered position are set it should just have to alternate between the two based on input from the transmission or toggle...
It is an 06 Outback and has no option integrated to make the mirror do this so I would be wiring everything up...
Last question, how hard is a dead reckoning to set up? I mean if I time the movement track from normal to down on the mirror and average would I use that for my time and then the directional inputs to the arudino?
The problem with dead reckoning is that small variations in voltage, temperature, etc. will always cause it to drift out of alignment. It may hold for a day, a week, a month there is no way to tell, but it will lose it's adjustment probably sooner rather than later.
And it needn't be any more complicated than a single servo that allows manual override movement. The angle change is tiny. A cam or even crude lump on the back of the mirror would even work with a spring to have a home position and then tilted position.
Up to you to disassemble the mirror housing and see what you have to work with. No one on here can tell what you have, and suggestions will be made with insufficient information and will lead to a long back and forth of "your suggestion didn't work because blah blah" "well you never said blah blah", etc.
Power mirrors, there is a small circular knob the clicks up for neutral, so even if you toggle it no mirrors move. And to the right is the passenger and the left driver side. I was going to use the up (or neutral) as my dead position. I figure that if I only allow the mirror to move when it's toggled to that mirror and the car is in reverse if I set both those parameters as true in order to make it move; it still allows me and other drivers to make adjustments in park w/ out the mirror moving. That way the car has to be in park and the knob to the right to trigger the movement. Also the mirrors are heated which means I have an extra always hot wire to use for a sensor.
In reply to INTP, I agree, I have a pretty good understanding what's going on behind the mirror but I will post a dissection so everyone kinda has an idea.
One thing to check is whether you can accomplish your desired motion with only the UP/DOWN motor. That would simplify things.
I don't see why you would say "obviously not an accelerometer". I would think that an accelerometer would be the most likely solution if only UP/DOWN tilt is needed.
To get position feedback with two degrees of freedom you need two or more distance/displacement sensors. It is possible that magnets and analog hall-effect sensors might do the trick.
Make sure you design it so that the Arduino can't try to drive the mirror one way while someone is trying to manually drive the mirror the other way. That is likely to cause an electrical short.
My electrical knowledge is not well define so I was under the impression that accelerometers measured acceleration by small fibers making contact with each other, similar to placing two hairbrushes together. I just need a solution that is waterproof and still allows for mirror movement.
I work in a body shop and have replaced LOT'S of side mirror's. no Subaru's that I can recall though.
All of them that I have torn apart simply had 2 geared DC motors.
The interesting thing is that for most manufacturer's the internal parts are often the same across several model's/years so it may be worthwhile to check if that is the case with your Subaru's. A trip to the junkyard may get you usable parts with the position sensor's. Of course figuring out how to read those sensors would be your next challenge.
As an aside they are a cheap source for a easily hacked tilting platform.
