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Four Extra Pins from Sd-Card Slot — Parallax Forums

Four Extra Pins from Sd-Card Slot

JamesxJamesx Posts: 132
edited 2010-02-08 01:30 in Propeller 1
I use OLED-96-Prop units for prototyping, as I like the size, little screen, and integrated voltage regulators. One compromise though, is having only four Propeller pins for I/O. This is a report of a "method" for gaining access to 4 additional pins, utilizing the SD-Card slot.


Concept: start with a spare micro-SD card; grind off the surface of this card, such that the card's pads are disconnected from the inner working of the SD-card; carefully solder on four 26-g wires to pads 2,3,5 and 7; gently insert (jam) the modified SD-card into the card slot; test.

I was doubtful that it would fit and even if it did, I was skeptical that it would work. It did require a little extra pressure to get the modified card into the slot, but it did go. To my surprise, the connections between the card and the board are solid: viola--4 more pins!

Attached are three photos illustrating 1) SD card after grinding; 2) after soldering; 3) after insertion into slot, showing path of wires.

Jim

Post Edited (Jamesx) : 2/7/2010 9:31:21 PM GMT
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Comments

  • hover1hover1 Posts: 1,929
    edited 2010-02-07 18:47
    Interesting solution to to problem of a lack of I/O on the OLED-96. I tend to use the uSD card 90% of the time, so I went with Tim's solution:

    ·http://www.brilldea.com/product_uoledioc.html

    Although he doesn't produce them any more, (I guess because 4D doesn't make the OLED-96 anymore), it could be reproduced pretty quickly.

    ADDED:
    I'm actually working on a project this weekend to drive 16 solenoids from Tim's board for a water feature using the uLED-96-Prop.

    Jim

    Post Edited (hover1) : 2/7/2010 6:56:58 PM GMT
  • Kal_ZakkathKal_Zakkath Posts: 72
    edited 2010-02-07 21:22
    Another option would be to etch a PCB the same shape as uSD card but a tad longer to allow for·soldering wires on the end, similar to Sparkfun's uSD sniffer board:

    http://www.sparkfun.com/commerce/product_info.php?products_id=9419
  • JamesxJamesx Posts: 132
    edited 2010-02-07 21:32
    Hover1: Thanks for the note about the Brilldea unit: I had not seen that one before. Too bad they're discontinued.
    Kal: As for etching a PCB, like the sniffer board, that's a possibility too. Maybe a bit beyond my current capabilities, but something to aim for.


    Jim
  • Timothy D. SwieterTimothy D. Swieter Posts: 1,613
    edited 2010-02-07 22:31
    Thanks guys for the good feedback on the uOLED-IOC carrier. Hover1 is correct, at this time the product is discontinued. You could do something with an I2C I/O expansion IC. If it would help, I could order more PCBs too and just sell the PCBs. Next time I do a round of PCB ordering, probably a few weeks from now, I can easily get a handful more of this PCB since we've already paid the tooling costs. How does that sound? We could stock just the PCB. I might have some extra ICs laying around, but I would need to verify the inventory first.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Timothy D. Swieter, E.I.
    www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, 3.0" LCD Composite video display, eProto for SunSPOT
    www.tdswieter.com
  • hover1hover1 Posts: 1,929
    edited 2010-02-08 00:59
    Tim, I would be in for 6 bare PCB's, but I don't think that would justify a panel being made.

    If you wanted to sell extra IC's, that would be great too.

    Jim
    Timothy D. Swieter said...
    Thanks guys for the good feedback on the uOLED-IOC carrier. Hover1 is correct, at this time the product is discontinued. You could do something with an I2C I/O expansion IC. If it would help, I could order more PCBs too and just sell the PCBs. Next time I do a round of PCB ordering, probably a few weeks from now, I can easily get a handful more of this PCB since we've already paid the tooling costs. How does that sound? We could stock just the PCB. I might have some extra ICs laying around, but I would need to verify the inventory first.

  • Timothy D. SwieterTimothy D. Swieter Posts: 1,613
    edited 2010-02-08 01:30
    Hover1 - It really isn't a problem for me to order something like 20 or 25 PCBs. I just want to order it with other PCBs because it would be US$40 shipping just for the IOCs which wouldn't make it worth it. I will have to get back to you on the ICs......wait...this just in......I have 5 ICs. Of course, I could potentially get more if I place an order for parts in the coming weeks before the PCBs.

    So - hang in there, I will keep the thread informed on an order and availability.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Timothy D. Swieter, E.I.
    www.brilldea.com - Prop Blade, LED Painter, RGB LEDs, 3.0" LCD Composite video display, eProto for SunSPOT
    www.tdswieter.com
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