SPC Digital Caliper Interfacing

Archiver

If the caliper uses a standard and open communication protocol to a
serial PC port then I believe that this could be easily read.
ACJacques

Aaron Nielsen wrote:
>
> Hello;
>
> I think I may have found a solution to my measuring problem however
> there is still one missing link. I have been looking to somehow get
> accurate length measurments into my stamp for logging I have come
> across al sorts of digital calipers that say they have SPC output I
> was wondering if anybody knew how I might be able to get my stamp to
> read this device.
>
> Thank You
> Aaron Nielsen
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

Archiver

Hello;

I think I may have found a solution to my measuring problem however
there is still one missing link. I have been looking to somehow get
accurate length measurments into my stamp for logging I have come
across al sorts of digital calipers that say they have SPC output I
was wondering if anybody knew how I might be able to get my stamp to
read this device.

Thank You
Aaron Nielsen

Archiver

> Aaron Nielsen wrote:
> ... I have been looking to somehow get
> accurate length measurments into my stamp for logging I have come
> across al sorts of digital calipers that say they have SPC output I
> was wondering if anybody knew how I might be able to get my stamp to
> read this device.

Mitutoyo SPC protocol is 3-wire, CLK, DATA, REQ.
CLK and DATA are open-collector outputs.
Pulling REQ low produces 52 clocks, DATA valid on
CLK low, each group of 4 bits represents a hex #,
lsb to msb:

d0-d3 0Fh

d4 sign digit, 0 is positive, 1 negative

d5-d10 measurement value, BCD, MSD to LSD,

d11 decimal point position in the 6-digit
measurement value, counting right to left

d12 units, 0=mm, 1=inches

A complete read takes about 34 milliseconds. Not sure
a BS1 is up to it, but faster STAMPS should. Anyway,
I've used these devices in a number of apps. Slow, but
works well, and easy to use. Any questions, just ask.

Jack

Archiver

Jack,

Thanks for the info, that's pretty cool, hope it works for mitutoyo
drop gages too.

Only I'd like to zero it and then grap the data as well.

Anymore info if this might be possible. The drop gage does have manual
zero button.

TIA,

Mark


--- In basicstamps@y..., goflo@p... wrote:
> > Aaron Nielsen wrote:
> > ... I have been looking to somehow get
> > accurate length measurments into my stamp for logging I have come
> > across al sorts of digital calipers that say they have SPC output
I
> > was wondering if anybody knew how I might be able to get my stamp
to
> > read this device.
>
> Mitutoyo SPC protocol is 3-wire, CLK, DATA, REQ.
> CLK and DATA are open-collector outputs.
> Pulling REQ low produces 52 clocks, DATA valid on
> CLK low, each group of 4 bits represents a hex #,
> lsb to msb:
>
> d0-d3 0Fh
>
> d4 sign digit, 0 is positive, 1 negative
>
> d5-d10 measurement value, BCD, MSD to LSD,
>
> d11 decimal point position in the 6-digit
> measurement value, counting right to left
>
> d12 units, 0=mm, 1=inches
>
> A complete read takes about 34 milliseconds. Not sure
> a BS1 is up to it, but faster STAMPS should. Anyway,
> I've used these devices in a number of apps. Slow, but
> works well, and easy to use. Any questions, just ask.
>
> Jack

Archiver

The "SPC" protocol is common to all "SPC" devices, AFAIK.
I've used SPC dial indicators, travel gauges, micrometers,
linear encoders, and digital calipers.

One foo factor: SPC employs a mix of proprietary and standard
connectors. They're quite expensive, and it can get frustrating
trying to figure out what's what - Be prepared for some homework.
The cables do seem to last forever - My original hack is some
13 yrs old, still works.

The indicator does'nt care where "zero" is - Simply store
the initial position, subtract it from subsequent positions
for the offset.

regards, Jack

auto106947@h... wrote:

> Thanks for the info, that's pretty cool, hope it works for mitutoyo
> drop gages too.
> Only I'd like to zero it and then grap the data as well.
> Anymore info if this might be possible. The drop gage does have manual
> zero button.