Hi everyone. I have a project where I want to know the position of a pole over 360 degree. I only do one turn from 0 to 360 degree.
I found that best solution is rotary Encoder. I do understand the principle, but can't find one encoder to buy (too many model).
The pole is 50 feet away from the Arduino board and outside with temperature range from -30 to 30 degree Celsius.
I think I need an absolute encoder as I want the current direction of the pole when I need it. (or maybe I could use an incremental encoder and track it with the Arduino board).
Anyway, if someone can help understand what I need it would be greatly appreciated.
An absolute encoder would work but they tend to use a lot more pins or utilize a serial data format. What you might research is a quadrature encoder with an index output. This supplies an additional output signal that is active at one specific position per revolution. This can be used as a home position indicator.
Sounds like you want a potentiometer with a local amplifier. Digikey, among others, sells pots optimized for use as absolute rotary position sensors. Driving the signal over a 50 ft line is a bit tricky -- I think you probably want a voltage to current converter on the transmitter side combined with a simple resistor to turn the current back in to a voltage at the Arduino end.
Thanks for your reply. I actually use a potentiometer to "act like" a rotary encoder in other project, but potentiometer are not 360 degree rotable. and the precision obtained at extremity is not really great (even if I use linear pots).
What is the output of an quadrature encoder? what kind of resolution could I expect?
Vitesse: get a potentiometer that is sold as a rotary position sensor. They are going to be more expensive, but they will rotate 360 degrees and give you what you need.
