Is this Absolute Encoder suitable for my project?

[amit88]

Hi

I need to use an encoder in my final year project. I need the encoder to record the movement of a voltage control knob. The knob will be rotated clockwise and anti-clockwise several times during its operation. The range of its movement will be limited between 0 - 70 degrees ( I am trying to achieve a resolution of 0.5 degrees, I understand this encoder will only be able to give upto 64'').

Now, I am planning to use the EAW- Absolute Contacting Encoder (ACE)
(Part no: EAW0J-B24-AE0128L), could you please tell me if this encoder will be able to give me the correct position if I first rotate the knob clockwise and then a few degrees anti-clockwise ? Not sure if the absolute encoder has a sense of direction.

Thanks

Amit

P.S Here is the datasheet for the encoder : https://www.electro-tech-online.com/custompdfs/2011/03/ace.pdf

 

[misterT]

The resolution of that encoder is ~2.8 degrees (128 states in one revolution).

 

[Reloadron]

I don't see the encoder you linked to as a solution. First 360 degrees of rotation acquaints to 128 states which is at best about 2.8 degrees of rotation per step. This is what mister T points out. Far from the .5 degree resolution you want or need. Next, if you look at the table in the data sheet, for the pin output code you will see it would be difficult to decode. You mention your pot is only using 70 degrees of rotation.

Given a choice and not getting too expensive I might lean towards using something like this which will give you an analog output of about 11 mV per degree as an analog output. Something I figure would be easy to decode to rotation.

Ron

 

[dknguyen]

You can also use a high quality potentiometer. Resolution is only limited by your ADC and even the very best are MUCH cheaper than an absolute encoder if you don't need continuous rotation.