[sdiy] sin/cos pot

[paula at synth.net]

Issues I see with a sin/cos pot; 

Use of 2 x ADC channels (more expensive than logic inputs) 

Slightly more complex software for reading/processing the sin/cos
outputs. 

Advantge; you get an absolute position. 

if you want more resolution from a regular grey code rotary encoder. you
can use double edge triggering. 

So instead of just picking the rising edge on one channel, use both
edges, this will give you 48PPQN with a 24PPQN encoder. 

I guess, though not tested, you could go a step further and use edge
detection on both channels and both edges on both channels giving you
96PPQN from a 24PPQN encoder, though I would expect switch bounce to
cause more of a problem at this resolution. 

Downside; no absolute position. 

Paula 

On 2017-07-10 11:31, Julian Schmidt wrote:

> I also found them at www.adimpex.it [1] for 1.15EUR/pcs. but they have a minimum order amount of 200EUR :-/
> still looking for a better sample source.
> 
> Am 10.07.2017 um 12:09 schrieb Michael Zacherl: 
> 
> On 9.Jul 2017, at 12:42 , Julian Schmidt <elfenjunge at gmx.net> wrote:
> 
> Anybody has an idea what the part number for the continuous alpha pots is?
> I just asked the other day for an encoder alternative with higher resolution, they would be great!
> Maybe I'd have to ask my distributor in taiwan about them.
> 
> Thanks for sharing, didn't know such a pot exists.
> How would you tell the direction of the movement?
> 
> BTW, $15 ... hm ... needs quantities I'd guess ... 
> https://www.aliexpress.com/item/1pcs-ALPHA-RV112FF-40B3N-22F-0B10K-Encoder-360-degree-turn-gain-potentiometer/32751858615.html
> 
> Thanks, Michael.
> 
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Links:
------
[1] http://www.adimpex.it/
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