[sdiy] Question how to improve rotary encoder feel

Wed Jun 14 11:59:41 CEST 2017

we use this chip on a product i'm working on that is essentially three hall
sensors on a chip, mounted under a magnet w/bearings connected to a knob.
sounds like the same idea.

https://www.ichaus.de/product/iC-TW11

On Sat, Jun 10, 2017 at 12:10 AM, Ben Bradley <ben.pi.bradley at gmail.com>
wrote:

> I've thought about this for a while. The readily available/cheap
> encoders give 12 to 24 pulses (or rest positions - they generally go
> through the whole 4-transistion quadrature sequence for each position)
> per rotation, so take many turns to set a value with reasonable (128
> or 256 position) resolution. I noticed in the late 90s the HP and Tek
> equipment had nice high-resolution optical encoders, butsuch encoders
> were $30 range, and still are. They're good and "affordable" if you're
> going to use one incremental encoder that is switched between all
> functions:
>
> https://www.digikey.com/product-detail/en/bourns-inc/
> ENS1J-B28-L00256L/ENS1J-B28-L00256L-ND/1089392
>
> I've had the idea of using two analog hall-effect sensors mounted ad
> right angles to detect the rotation of a magnet on the end of a shaft.
> They'll give a sine-and-cosine output of shaft position that you can
> run into the DAC of a microcontroller and use an arc-tangent function
> to get the shaft angle. With a little multiplexing, a single
> controller can read many shaft positions simultaneously (okay, fast
> enough to appear simultaneous). I was hoping I was the first to come
> up with the idea, but I saw it mentioned in the SDIY archives maybe
> six years ago.
>
> I've got a few DRV5053 from TI, they're cheap enough at a dollar each.
> and about $0.50 for higher quantities. There are several models with
> different suffixes indicating different magnetic sensitivities:
> https://www.digikey.com/product-detail/en/texas-
> instruments/DRV5053RAQLPGMQ1/296-40066-1-ND/5177943
> They're available in SMT but to use them this way you'd have to mount
> one on each of two PCBs, and set the PCBs at a 90 degree angle to
> sense the field.
>
> I saw this video a few months ago, he says these are the only two
> prototypes of this synth. I think this is a great interface, it's the
> ultimate as far as any ideas I have. Each function has its own knob,
> and the horizontal LED bar (that goes across the whole front panel)
> shows the value of the control when you touch the control, and varies
> as you turn the control. I wonder of each of those controls is one of
> those expensive optical encoders:
>
> https://www.youtube.com/watch?v=xiV7lzYuM8I
>
> On Fri, Jun 9, 2017 at 5:31 PM,  <paula at synth.net> wrote:
> > Pete,
> >
> >  Yes, I love the use of neopixels for the rings, just awesome.
> >
> > Paula
> >
> >
> >
> > On 2017-06-09 23:25, Pete Hartman wrote:
> >
> > I assume you've seen the Euclidean Circles module?
> >
> > Pete
> >
> > On Fri, Jun 9, 2017 at 4:22 PM, <paula at synth.net> wrote:
> >>
> >> Just remembered these puppies ;
> >>
> >> http://mayhewlabs.com/products/rotary-encoder-led-ring
> >>
> >>
> >>
> >> Shame they're discontinued.
> >>
> >> Paula
> >>
> >>
> >>
> >>
> >>
> >> On 2017-06-09 15:53, Elain Klopke wrote:
> >>
> >> I know this is still expensive, but very interesting.... select up to
> >> 16-bit resolution...
> >>
> >>
> >> https://www.digikey.com/product-detail/en/AMT102-V/
> 102-1307-ND/827015?WT.mc_id=IQ_7595_G_pla827015&wt.srch=1&
> wt.medium=cpc&WT.srch=1&gclid=CjwKEAjwjunJBRDzl6iCpoKS4G0SJACJAx-
> Vl4p0hPzBSpwzSQG49Jod93fHxdtBAS0jDJDcRSuR8RoCIE3w_wcB
> >>
> >> On Fri, Jun 9, 2017 at 8:21 AM, Tom Farrand <mbedtom at gmail.com> wrote:
> >>>
> >>> At least some of the encoders on ham equipment are optical encoders.  I
> >>> repaired one within the last year.  (The knob has the requisite
> fingertip
> >>> indentation.)  Being optical in nature, control can be almost anything
> you'd
> >>> want.  I would guess that the resolution was maybe 120 PPR or better.
> The
> >>> specific unit was a Yaesu FRG-100 general coverage receiver and the
> optical
> >>> encoder was the main tuning dial.  If these could be obtained
> inexpensively,
> >>> they would be wonderful for synth control.  It has been a while since I
> >>> looked but think that even these "cheapie" encoders are still in the
> $30 -
> >>> $40 range (or more).
> >>>
> >>> Tom Farrand
> >>>
> >>>
> >>> On Fri, Jun 9, 2017 at 7:49 AM, Steve <sleepy_dog at gmx.de> wrote:
> >>>>
> >>>>
> >>>> Tom Wiltshire wrote:
> >>>> > I did many experiments trying proportional control of a parameter
> >>>> > using the velocity of the encoder. It was a disaster, in short.
> Mostly much
> >>>> > too sensitive, or much too slow. In the end, I finished up with a
> system
> >>>> > like you suggest, > where you can push the encoder for fine control.
> >>>>
> >>>> That reminded me of something else with built-in "switching" between
> >>>> coarse and fine control:
> >>>> Those encoder knobs on many HAM radio transceivers to tune, with a
> dent
> >>>> near the outer radius, where you can rest your fingertip and use the
> thing
> >>>> as a crank with very quick rotations, or grab the whole thing for fine
> >>>> control.
> >>>> Needs more space of course, for those things are bigger than the
> average
> >>>> knob on a synth module. And the encoder has more wear if the solution
> is
> >>>> "turn it more!", if it's a mechanical one. And I'd guess things
> finger tip
> >>>> cranking doesn't feel nice with some encoders hard detent.
> >>>> Something like this:
> >>>>
> >>>> https://www.adafruit.com/product/2055https://www.
> adafruit.com/product/2055
> >>>>
> >>>>
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