Magnetic encoder object

Graham Stabler

Nothing special but it works. Assembly object for reading data from an RLS AM256L absolute magnetic encoder, roughly 40us for a read.

www.rls.si/default.asp?prod=chips

I notice the one I have has been replaced but they all seem to be very similar, might just need a tweak of the delay times.

Great little things, 8-bit and absolute, no mounting issues lots of fun. I wish I had coded it up 2 years ago when I go it, only took a couple of hours.

Graham

Timothy D. Swieter

Cool. I believe Autstria Microsystems also has magnetic encoders for those interested.

One thing that I wonder about regarding a magnetic encoder is the mechanical design. I feel like a design has to be more detailed and custom to use a magnetic encoder. Graham, how did you test your design? Any cool pictures of the test jig to share?

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Timothy D. Swieter, E.I.
www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, 3.0" LCD Composite video display, eProto for SunSPOT
www.tdswieter.com

Graham Stabler

It's swings and roundabouts, or to put it another way if a snake had wheels it wouldn't need as many ribs.

In my case I got one of the chips mounted on a PCB as a sample, that means all I need to do is mount it on two little stand offs and make a very simple adapter to hold the magnet on the end of the shaft. Compared to normal shaft encoders this is actually much easier and lets you put an encoder where you might otherwise struggle, for example the magnet could even just be glued on to a face of a disk as long as it is centered or inserted into a drilled hole. But of course if you don't have an end on your shaft (say it couples two robot wheels) it is not so helpful.

You can also get packaged versions of these devices (us digital do one too) which are ideal for front panels, OBEX has an object for one of them.

To test I just held the magnet in my hand in front of the chip, being absolute this was fine for testing.

Graham