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Topic: Rotary encoder together with arduino for measuring angle (Read 3156 times) previous topic - next topic

Hi!
I have a question regarding absolute rotary encoders. I need a rotary encoder to measure the angle an axis is
tilted. The axis is not supposed to move around in circles. It will just be able to turn 180 degrees clockwise and
180 degrees counterclockwise.The rotary encoder mounted on the axis is supposed to give me the current angular position of the axis related to a fixed, origin position. The encoder should also be able to tell if the axis has been tilted clockwise or counterclockwise from the origin position. (I will use an Arduino platform to interpret the signals from the encoder) Which rotary encoder is best to use? Or should I use another form of component for angular measuring? As written before, it should be easy to connect and use with the arduino platform.

Grumpy_Mike

Absoloute rotary encoders are expensive, I would suggest what you need here are three simple tilt switches mounted at the appropriate orientation.
Otherwise go for an accelerometer.


PaulS

Are you rotating about just one axis? If so, any rotary encoder should work. If you can spare both interrupt pins, then reading the encoder, including direction of rotation, is trivial. Knowing that the encoder has moved n steps one way or the other lets you keep track of how far from 0, plus or minus, it has moved.

thanks for the answers. :)
The precision should be approximately +/-5 degrees. And yes, the the rotation will only be in one axis.
How good precision can I get from a relativly cheap rotary encoder? or is it better to use an accelerometer as suggested?

Grumpy_Mike

You get about 16 clicks per revolution on most encoders some even less.

Chagrin

http://www.mouser.com/ProductDetail/Bourns/EAW0J-B24-AE0128L/?qs=sGAEpiMZZMvy8cVzszrmR716n9pC3kk%2fKdD7OIhGwoE%3d

Absolute encoder with 128 positions. Under $7.

Grumpy_Mike

That looks great.
Also available on this side of the pond at:-
http://uk.farnell.com/bourns/eaw0j-b24-ae0128l/encoder-rotary/dp/9358234

Mind you it has a grey code output so it will need converting.

Thanks for the answers, they have been very helpful! :)
The encoder which gives 128 readings in one revolution sounded like
the best choice, so i will probably go for that one. Thanks for
posting the links to were I can buy them. :)

michinyon

You could also use a potentiometer and measure the resistance.

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