How to Scale Absolute Encoder Output Signal ?

Hi,
Our application is for Tower Crane. We intend to use multi turn absolute rotary encoder to give us tower crane azimuth position data (0-360deg). With our biggest crane, 1-complete revolution for the tower Crane will take about 14+ turns for the absolute encoder. Can anyone please teach me how can i scale the signal output from the encoder vs the tower crane position. If for instance the Single turn Resolution is 2^18 (262144) and Multi turn resolution is 2^6 (64 turns).

I am not sure if this can be done programmatically or Arduino have product support on this.

I would appreciate for any help. Thanks a lot.

I find your question confusing. Are you proposing to use two encoders, one with 18 bit resolution and another with 6 bit resolution, which are attached to gears in some way?

Perhaps a diagram would help.

Hi Paul,
Thank you for the reply.
It is only ONE encoder which has spec. single turn resolution of 2^18 and multi turn resolution of 2^6.
I have attached a picture for reference.

I have also attached an illustration of the tower crane gear vs the encoder small gear.


Did you forget to attach the other picture? That one is only slightly helpful. Can you post a link to the encoder? (See forum guide how to post links so they can be clicked).

So, if I understand better now, the rotary encoder will, in effect, produce an output which is a 24-bit number?

What I still don't understand is that you said that one crane revolution will be 14+ turns out the encoder. If it is exactly 16 or 32 turns, then I can see how your idea could work. But for any other ratio, I'm not sure how you can determine the crane's absolute position from the reading. The reading would be ambiguous, wouldn't it?

Your diagram shows the crane year having 36 teeth and the encoder gear having 11 teeth. So that's not a simple ratio. If the encoder gear had 12 teeth, it would be a 3:1 ratio, which would still give ambiguous readings. If it had 9 teeth, that would a be a 4:1 ratio, which would be easy to work with.