Need to use Homework board .

Hi,

I need to connect the Homework board microcontroller but without the USB cable.

I need to connect the homework to my old computer using the old serial connection DB9 of the old computer.

I need help to know if it is possible to "jump" or distroy the USB circuit and transfom the USB Homework in to a DB9 Homework.

Please see the picture.

thanks.
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Comments

  • 10 Comments sorted by Date Added Votes
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 20,979
    edited July 2016 Vote Up0Vote Down
    I think you'll have a problem without some extensive, tedious rework to the Homework board. It would be better to get a USB-port plug-in board for the old computer, assuming it's running an op system that supports USB. Is there a reason that you have to use that PC and not something newer?

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • But I have and old homework that works very fine with the DB9.

    And I would like to to something similar.

    USB is not usefull for me.

    Please help.

    1296 x 968 - 541K
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 20,979
    edited July 2016 Vote Up0Vote Down
    There's more than just a connector involved. You also need an inverting level translator to convert the +/-12V RS232 values to +5V logic levels. Then you'll have to cut some tiny traces on the Homework board, carefully scrape off the green solder mask, and solder some very fine wires to them to connect the level translator. This is not a job for someone who's never done solder rework before; but if you're experienced, it's not insurmountable either.

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • PublisonPublison Posts: 9,449
    edited July 2016 Vote Up0Vote Down
    The Board of Education DB9 is still available:
    https://www.parallax.com/product/28150
    Of course you would have to add a BS2 to it:
    https://www.parallax.com/product/bs2-ic

    There is a cheaper board, but you would have to add the BS2 to it also:
    https://www.parallax.com/product/27120
    It is on sale.

    I see you are in Chile, so shipping may be a problem.


    Infernal Machine
  • When you say "old" computer, does it only have ISA slots, or does it have at least one PCI slot?
    Infernal Machine
  • I'm late to this party. I'm proud to own the very last box of serial HW boards that Parallax ever sold. Angela, where are you?
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • Couldn't you just use a USB to serial cable or converter to plug a USB Homework board into a DB9 serial port?

    Maybe something like:
    https://parallax.com/product/28030
  • The Parallax board creates a serial interface from a USB host (i.e. the PC). The OP would need to create a USB host from a serial interface. That would take a different kind of module -- if they even exist.

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • Simple serial - TTL interfaces:
    http://picprojects.org.uk/projects/simpleSIO/ssio.htm
    http://forums.parallax.com/discussion/85344/simple-serial-interface-for-propeller-programming

    Still needs to be connected to the lines requiring either the cutting of traces or the removal of some smd components in the USB circuit
    Stockholm, Sweden
    I am only an egg -- Stranger in a Strange land, Robert A. Heinlein
  • Still waiting for Angela to contact me and my big box of new serial HW boards.
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
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