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Stamp PLC

SuttonSutton Posts: 3
edited 2019-12-15 05:55 in BASIC Stamp
Hi all.

Hope someone can help me. I have one of those discontinued stampplc boards. I'm hunting the electronic schematic diagram for this device. I found only a pdf file with some programming advice on the web. Not enough info if you trying to get your head around some of the components on the board.

Could someone please help me out with such a schematic drawing of the stampplc.

Comments

  • kwinnkwinn Posts: 8,697
    Take a look at this web site and this parallax post as a starting point.
  • kwinnkwinn Posts: 8,697
    Also found this PDF from Digikey. Hope it helps. If not, just having the data sheets for the chips should make it possible to produce a schematic, although it may be a bit tedious.
  • Kwinn
    Thanks for your links and file.
    However i don't see any electronic schematics/diagrams for this device in the links.
    Your file is what i referred to as the "pdf file with some programming advice". This also doesn't include the electronic schematic for the device

  • kwinnkwinn Posts: 8,697
    Sorry I couldn't be more help. I could not find any schematic after a lot of hunting. Have you tried contacting Maxwell Stamp?

    If you can't get a schematic from them it looks like a bit of reverse engineering may let you figure it out if you can read the chip numbers. It will be a bit tedious but there are only 7 areas to examine. Starting at the top left of the attached image they are:

    1 - 4 jumpers that may be connected to the IC below them.
    2 - The IC below the jumpers that may possibly interface the jumpers to the Stamp.
    3 - 8 4 pin opto-isolator and driver IC's connecting to output terminals
    4 - The Stamp module
    5 - A power supply module.
    6 - An HC165 parallel to serial shift register
    7 - 10 opto-isolator inputs, 8 connected to the HC165, 2 going elsewhere.

    If you can read the part numbers on all the components you would be well on the way to producing a schematic.
    676 x 728 - 999K
  • Hi Kwinn

    Many thanks for your efforts.

    It seems like i will have to go down the route of analysing the module.
    I even have one of those computer connected microscope to help me with identifying those really small parts.
    But like you said it is still very tedious and very time consuming doing it in this way.
    I just thought it will be easier asking for such an already drawn schematics.
    If my memory serves me right i remember seeing such a schematics years back on the web, hence thinking i should find it quick among your guys. (that after not finding it on the web)

    Thanks again for your time spend
  • kwinnkwinn Posts: 8,697
    Sutton wrote: »
    Hi Kwinn

    Many thanks for your efforts.

    It seems like i will have to go down the route of analysing the module.
    I even have one of those computer connected microscope to help me with identifying those really small parts.
    But like you said it is still very tedious and very time consuming doing it in this way.
    I just thought it will be easier asking for such an already drawn schematics.
    If my memory serves me right i remember seeing such a schematics years back on the web, hence thinking i should find it quick among your guys. (that after not finding it on the web)

    Thanks again for your time spend

    You're welcome. Hope you will post the schematic in this thread once you complete it. While analyzing the module will take some time I don't think it will be too much with the tools you have.The board seems to be divided into sections, which should make the task easier. Knowing the basic function of the module and having the data sheets of the IC's on the board will be a big help.

    First thing I would do is set up a spreadsheet to list all the IC pins and use the microscope to see what those pins are connected to, and list the components on the spreadsheet. After that I would use the meter to ohm out connections that were not visible.
  • JonnyMacJonnyMac Posts: 8,912
    edited 2019-12-24 00:34
    Do you have this document?
    -- https://media.digikey.com/pdf/Data Sheets/Parallax PDFs/30064.pdf

    Device #3 is a MAX120 ADC
  • I wondered about this myself. The opto couplers (#7) are LVT-357, the output N-channel FET switches (#2) are an obsolete IPS511G, the shift register (#6) is a HC165, (#1) header jumpers are for 4-20Ma input resistor for the (#3) Max120. The Stamp module pin outs are 8-15 for the output FET switches pins 3-5 for the Max120, pins 1-2 for the 74HC165, pin 0 is a shared clock pin. Pin 6-7 are digital input 9-10. The pins reflect P0-P15 on the stamp module.

  • Correction (#3) is a Max1270.

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