[sdiy] Question how to improve rotary encoder feel

[Ben Stuyts]

Hi Mike,

Yeah, looks good to me! It has quadrature and I2C output, so should be easy to interface. And also push-button detection if I see correctly.

Ben


> On 12 Jun 2017, at 04:27, Mike HEQX <mike at heqx.com> wrote:
> 
> Ben,
> 
> The AS5601 is only $1.65, it seems to have the same resolution as the AS5045, but is not a PWM output. Is that a bad thing?. I'm glad you mentioned this part. I am working on a sequencer and this may save me a ton of grief.
> 
> Mike
> 
> 
> On 6/11/2017 12:02 PM, Ben Stuyts wrote:
>> Speaking of Hall sensors reminded me of a visit of a local rep for AMS a while ago. He showed me a demo board of one of their rotary hall effect sensors. I think this was the sensor:
>> 
>> http://ams.com/eng/Products/Magnetic-Position-Sensors/Angle-Position-On-Axis/AS5045
>> 
>> It generates a 12 bit position (4096 steps/rev). Cost is €6 - €10 depending on qty. And this is the (expensive) demo board:
>> 
>> http://ams.com/eng/Support/Demoboards/Magnetic-Position-Sensors/Angle-Position-On-Axis/AS5045-Demo-Kit
>> 
>> They have a whole range of Hall sensors. Some of them also measure the strength of the magnetic field, so you could also implement a push button function.
>> 
>> Ben
>> 
>>> On 10 Jun 2017, at 07:22, Ben Bradley <ben.pi.bradley at gmail.com> wrote:
>>> 
>>> I'm trying to send this a second or third time, my last attempt made
>>> it to the list but may have looked like an empty post.
>>> 
>>> 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
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at synth-diy.org
>>> http://synth-diy.org/mailman/listinfo/synth-diy
>>> 
>> 
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at synth-diy.org
>> http://synth-diy.org/mailman/listinfo/synth-diy