Get the Rotation of an Object on a Turntable

Trying to figure out module will work best. I have an Uno and want to have a turntable at a set automatic
speed. So say I have a turntable with a model airplane on it. I place the sensor the same forward facing direction of the plane. So zero degrees to start. Is there a way to use a sensor and get the rotation in the 360 degrees it would take to rotate around so I knew which position the plane was in at all times on the turntable?

A compass module maybe? Or a rotary encoder depending on how you have the turntable set up.

What type of motor is turning the turntable? A stepper would only need one sensor to provide a position reference.

Your description is very unclear.

Can you put the sensor (such as a compass module and an Arduino) on the turntable?

Is the Arduino driving the turntable?

Is the turntable completely separate from the Arduino so that, in a sense, the Arduino is a spectator?

Without knowing what you are dealing with it is impossible to give useful advice.

...R

Yes sorry the turntable is completely separate and driven by something out of my control. I just want the direction of the object on it.

mrekuc:
Yes sorry the turntable is completely separate and driven by something out of my control. I just want the direction of the object on it.

You have not said whether you are permitted to place a detector (such as a compass module) on the turntable?

OR, would you be able to put a small jockey wheel so it is rotated by the edge of the turntable so that the jockey wheel can drive a rotary encoder

OR could you attach a strip of paper (or similar) to the edge of the turntable with a series of black stripes on the paper which could be detected by a reflective optical sensor.

You really need to give us a lot more information.

...R

No I thought by saying I have no control over th turntable that you would get that I cannot do anything with the turntable other have a sensor on TOP rotating with the turntable. No wheels can be placed in conjuction with the turntable at all. It is a totally seperate element out of my control so I cannot rely on getting any info from it other then trying to get the orientation of it by placing a sensor on it. It is not a small turntable either. Actually pretty large. Big enough to place something as large as a life sized car equivalent on to.

Well if you can put anything on top of the turntable but nowhere else, then put a arduino and compass sensor on the turntable and broadcast the current heading.

OP. If you can't be clear about what you have and insist on vague partial descriptions then it isn't likely that you'll get much help. Instead of little clues sprinkled in every few responses, just give us the complete picture of what you're working with. Too much detail is way better than not enough.

I'm not trying to be vague at all. I literally just have a turntable with an object on it and trying to figure out how i can get the direction that object is on the turntable that is rotating on its own. The turntable cannot be controlled. I cannot put a motor on it. I'm here because I don't know and this is literally all i have to work with. I am not familiar with every sensor out there and have done a few projects involving buttons and bluetooth modules. I tried looking around first myself before posting here to get ideas. My initial thought was use an MPU-6050. But as few have suggested about using a compass being something that could work.

Your turntable has a rotating rim. Attach magnets along the rim and a hall sensor on the stationery floor, counting the number of magnets passing by. If you want absolute position, make the magnets form patterns, like binary code. Or replace magnets and hall sensor with barcodes and barcode reader. If you can place a full size car on the turntable, sure you can attach this, too.

mrekuc:
No I thought by saying I have no control over th turntable that you would get that I cannot do anything with the turntable other have a sensor on TOP rotating with the turntable.

I mentioned that in Reply #3 but you made no comment about it so I assumed it was not possible.

Post a diagram showing what you are working with including key dimensions. If you can post a photo of the turntable in its working position that would also help. See this Simple Image Guide

...R

I will post a diagram soon. I don't have the physical turntable here. It is being built in a warehouse.

How big is it? How is it driven? What does it look like? What parts DO you have access to? How is it made? Can you get inside? Is the motor under it or off to the side? Belt drive or gears? There are TONS of details you could provide aside from just telling us that it is "a turntable".

"Can you put the sensor (such as a compass module and an Arduino) on the turntable?"

If you -can- (which I'm STILL not clear if you can or can not?) put something ON TOP of the turn table.. then your solution was already given to you.

What type of 'direction' are you looking for?
angles?
north south eat west?
up down left right?

Simple Arduino Pro-Mini and Compass module.. done deal.

Delta_G I don't know any of that at all. i was asked if we could figure it out without touching anything of said turn table. I don't know how its built other then "hey this turntable will rotate slowly. Think and a vehicle on a turntable at an auto show if you've been to one. It is similar to that. There are a lot of unknowns as to whats driving it to me as well. this is why I am trying to figure out another solution with relying on anything that has to do with the turn table other then it spins and lets see if there a away to get that data.

So to Robin2's point yes the only thing I can do is put some kind of sensor on top of the turn table.

This basically all I'm looking to do. Its not so much the turntable itself or being able to tap into anything related to the turntable, but something i can put on the turntable to get the rotation of the object.

This gives more info thanks.

Can you put something in or on your model on the turntable?
Also answered, yes you can.

So a compass maybe? Why do you want to know the heading of the front of the object? Do you need to know this in real-time? Is accuracy very important or can you use lets say 4 readings, when the front passed, the left side, the back and the right side?

Yes in the model or on the turntable is fine. I need to know what it is all the time. Not just the 4 headings. Accuracy would be as good as I can get it.

EDIT: I should say to be more specific since other mentioned magnets, bar codes and motors on the side. Top of turntable would be fine. Not the sides.

A digital compass module?

Whre do you need to have this,info, shown on a screen? Send to you while you are away?