Home Mode Optical Encoders

Hi Everyone

I am trying to find some really old serail mice so I can use the
optical encoders from them with my DAvid EK DSC Interface that I have
built, but I am having a real problem trying to find the right type of
serial mouse, so I thought, why not just built an optical encoder
instead.

I was looking through the latest RS catalogue yesterday and I came
across the Honeywell Opto Encoder DEtector Part No HLC2701 and the
SEP8506 emiiter (which according to Honeywell's Website, is the
matching emiiter). SO my question is this. Could I just make one using
these emitter/detector pairs, with a disk from a serial mouse
inbetween them? Has anybody tried this before?

For only £2.12 for the detector and £0.93 for the emitter, itis got to
be a really chip way of making a encoder. I suppose I could even make
my own optical disk by printing it on transparent paper. What do you
think?

Any help on this guys, would be really greatfull, as I'm desperate to
gt my interface hooked up to my little homemade 4.5 inch dob.

Thanks
Andy

"Andy Podmore" wrote in message
om...
Hi Everyone

I am trying to find some really old serail mice so I can use the
optical encoders from them with my DAvid EK DSC Interface that I have
built, but I am having a real problem trying to find the right type of
serial mouse, so I thought, why not just built an optical encoder
instead.

I was looking through the latest RS catalogue yesterday and I came
across the Honeywell Opto Encoder DEtector Part No HLC2701 and the
SEP8506 emiiter (which according to Honeywell's Website, is the
matching emiiter). SO my question is this. Could I just make one using
these emitter/detector pairs, with a disk from a serial mouse
inbetween them? Has anybody tried this before?

For only £2.12 for the detector and £0.93 for the emitter, itis got to
be a really chip way of making a encoder. I suppose I could even make
my own optical disk by printing it on transparent paper. What do you
think?

Any help on this guys, would be really greatfull, as I'm desperate to
gt my interface hooked up to my little homemade 4.5 inch dob.

Thanks
Andy
The 2705, has the quadature decoder allready built in, which may be even
better for some appliations. The decoders work fine, but you need to
measure the pitch of your disk, to verify if it will be compatible with
the decoders. They are built for a line pitch of about 0.914mm. The 2705,
only decodes the alternate edges, giving two detections/line, while the
2701, will depend on your decoding logic, giving four detections/line if
you decode all the possible states. If your disk is a normal mouse unit,
it should be close to this pitch. You can vary the pitch slightly, by
positioning the detector further in/out on the disk. The two units se the
same line pitch.
I have suggested these in the past for exactly this reason. They are a
very cheap way of making an encoder. I used them, with a strip of film,
printed on a laser printer, to give linear position sensing.

Best Wishes