[sdiy] Rotary Encoder Design

[Jay Schwichtenberg]

I'm agreeing  with Achim. That by the time you're done making your own 
if you count your time it is probably cheaper to buy them. And as Achim 
said magnet alignment and calibration are going to major factors in 
getting things to work right.

About 6 years a go I worked on a project that used these sensors for 
linear positioning. The chip uses the BiSS bus which I will say is the 
worst serial buss ever, run and hide if someone asks you to program it. 
We had to have special magnets too. Most magnets have single north/south 
poles. The magnets we used had multiple magnets strung together like 
NSNSNSNS.

https://www.ichaus.de/product/iC-MHL200

You might check out some of their case studies and app notes on the web 
site.

Jay S.

On 7/26/2020 12:00 AM, ASSI wrote:
> On Samstag, 25. Juli 2020 21:58:22 CEST Ben Bradley wrote:
>> Now that I see that, I remember seeing a similar magnetic rotary
>> sensor years ago, that probably gave me the idea for this. The reason
>> I came up with using two single-axis Hall effect sensors is two of
>> them are still several dollars less than a one-chip angle sensor at
>> about $6 each.
> You don't do that.  By the time you've figured out the how to align and
> calibrate the magnetic circuits you'll be several times that dollar amount
> short unless your time is worth nothing.  Instead you use a sensor that has
> multiple Hall elements integrated and the necessary compensation already built
> in, like the TLV493D (disclosure: I work for the manufacturer, but not on that
> product line).  There's an eval kit that comes with magnetics and everything
> should you want to try it:
>
> https://www.infineon.com/cms/en/product/sensor/magnetic-sensors/magnetic-position-sensors/3d-magnetics/tlv493d-a1b6/
> https://www.infineon.com/cms/en/product/evaluation-boards/mini_control2go/
>
> There's even code on GitHub that you can crib (it also has the 3D print data
> for the knobs).
>
> https://github.com/Infineon/TLV493D-A1B6-3DMagnetic-Sensor
>
>
> Regards,
> Achim.