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Decoding SPC output with the Stamp — Parallax Forums

Decoding SPC output with the Stamp

ArchiverArchiver Posts: 46,084
edited 2002-06-05 15:03 in General Discussion
HI,

I have several DRO's (digital read outs) mounted on
my drill/mill and my lathe for accurate positioning.

Each DRO is essentially a digital caliper with an ability
to output a binary position serially.

I'm wondering if anyone in the group has ever decoded
the serial SPC output of a digital caliper? Looks like
my next stamp project will be a multi-axis SPC readout
to an LED or LCD display but I don't want to re-invent
the wheel!

All comments are welcome!

Thanks,
Greg

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2002-03-13 22:33
    At 01:17 PM 3/13/2002 -0800, you wrote:
    >HI,
    >
    >I have several DRO's (digital read outs) mounted on
    >my drill/mill and my lathe for accurate positioning.
    >
    >Each DRO is essentially a digital caliper with an ability
    >to output a binary position serially.
    >
    >I'm wondering if anyone in the group has ever decoded
    >the serial SPC output of a digital caliper? Looks like
    >my next stamp project will be a multi-axis SPC readout
    >to an LED or LCD display but I don't want to re-invent
    >the wheel!
    >
    >All comments are welcome!
    >
    >Thanks,
    >Greg
    Hi Greg -

    I sent you a PDF file off list, to the address contained in
    this email message.

    Regards,

    Bruce Bates
  • ArchiverArchiver Posts: 46,084
    edited 2002-03-13 23:29
    In a message dated 3/13/02 6:25:42 PM Eastern Standard Time,
    goflo@p... writes:


    > Bruce Bates wrote:
    >
    > > I sent you a PDF file off list, to the address contained in
    > > this email message.
    >
    > Hi Bruce -
    >
    > Could I trouble you for a copy of the document you mention?
    >
    > regards, Jack
    >
    >

    Bruce:
    I too would like a copy of the PDF file you mentioned. As luck has it
    I have been asked to interface an SPC device to a machine and I am looking at
    doing it with a BS2 or SX.

    Thanks in advance

    Regards,

    Randy Abernathy
    4626 Old Stilesboro Road
    Acworth, GA 30101
    Ph/Fax: 770-974-5295
    E-mail: cnc002@a...
    We service, install and repair industrial woodworking machinery
    Specializing in SCM / SCMI CNC Panel Saws and Routers


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2002-03-14 00:59
    Greg Hensley wrote:

    > I have several DRO's (digital read outs) mounted on
    > my drill/mill and my lathe for accurate positioning.

    > I'm wondering if anyone in the group has ever decoded
    > the serial SPC output of a digital caliper?

    Hi Greg -

    Mitutoyo caliper protocol is 3-wire, CLK, DATA, REQ.

    CLK and DATA are open-collector outputs. 10K pull-ups
    work fine.

    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

    IIRC CLK freq is 1562 Hz, or thereabouts.

    regards, Jack
  • ArchiverArchiver Posts: 46,084
    edited 2002-03-14 01:02
    Bruce Bates wrote:

    > I sent you a PDF file off list, to the address contained in
    > this email message.

    Hi Bruce -

    Could I trouble you for a copy of the document you mention?

    regards, Jack
  • ArchiverArchiver Posts: 46,084
    edited 2002-03-20 21:49
    At 04:59 PM 3/13/2002
    >Greg Hensley wrote:
    >
    > > I'm wondering if anyone in the group has ever decoded
    > > the serial SPC output of a digital caliper?



    In the absence of written stamp code to decode the serial bit
    stream from the calipers, I'll put it on my project list. This
    is a great stamp project! I'll post to the list when finished
    but don't hold your breath, I can procrastinate for months!!

    My thanks to Bruce and Jack for responding to my question.

    Greg
  • ArchiverArchiver Posts: 46,084
    edited 2002-06-05 15:03
    Hey Jack, I have a similar question. I'm trying to get the data from
    a Mitutoyo Indicator through the SPC connection. I'm having trouble
    actually obtaining the correct data. I'm using a 10k pull-up
    resistor and a 74HCT04N Hex inverter for the clk and data outputs.
    The stamp im using is the BS2p so I dont think its a sampling speed
    problem ...

    Here is an example of expected and returned data I'm getting. Maybe
    this will help:

    Number 25.83 mm

    Expected output:
    1111 1111 1111 1111 0000 0000 0000 0010 0101 1000 0011 0100 0000

    Obtained output:
    1111 1111 1111 1111 0000 0000 0000 0000 1111 0000 1100 0000 0000

    Thanks for your time!

    If you could reply to my work e-mail address, it would be much
    appreciated!

    P.S. there was also some pdf file going around - do you know what it
    contains?

    Carlos De Oliveira
    Halsall Associates Limited
    2300 Yonge St., Suite 2300
    Toronto, Ont. M4P 1E4
    Tel: 416-487-5256 ext. 332 Fax: 416-487-9766

    CDeOliveira@h...


    --- In basicstamps@y..., goflo@p... wrote:
    > Greg Hensley wrote:
    >
    > > I have several DRO's (digital read outs) mounted on
    > > my drill/mill and my lathe for accurate positioning.
    >
    > > I'm wondering if anyone in the group has ever decoded
    > > the serial SPC output of a digital caliper?
    >
    > Hi Greg -
    >
    > Mitutoyo caliper protocol is 3-wire, CLK, DATA, REQ.
    >
    > CLK and DATA are open-collector outputs. 10K pull-ups
    > work fine.
    >
    > 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
    >
    > IIRC CLK freq is 1562 Hz, or thereabouts.
    >
    > regards, Jack
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