QFN programming

Discussion in 'Embedded Systems and Microcontrollers' started by Shizman, Dec 16, 2008.

  1. Shizman

    Thread Starter New Member

    Dec 2, 2008
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    0
    Hi everyone,

    Not researching sufficiently, I just bought:

    PIC16F887-I/ML-ND (44QFN)


    Now I have the problem of not knowing how to get my code onto it. I have a programmer for PIN-based chips, but this is different of course.

    Everything I have found is VERY expensive to get my code onto the chip. Should I cut my losses and get a chip that's PIN or SOIC based?

    Also, what socket can I use to actually put this on my IC?

    Thanks!
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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  3. Shizman

    Thread Starter New Member

    Dec 2, 2008
    7
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    Ya, looks like this is about $200. That's a lot more than I wanted to pay.

    I was considering an adapter like this:

    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220282940990

    Would this help me? I have a PIN programmer that supports 40 pins though. Argh, this is frustrating. I think I'll just spend $5 or so and get the pin or SOIC-based versions.

    While we're on that topic, what can you use to program a SOIC chip?
     
  4. RiJoRI

    Well-Known Member

    Aug 15, 2007
    536
    26
    Look into the PICKit2. One of the boards (the debug module) has an 887 chip already.

    Also, I think there are DIY programming instructions for the re-programmable (F) chips. Check the uChip forum,

    As to how they are programmed, usually it's in-circuit: the board has a 4-6 pin connector which goes into the PICKit's socket, and away you go! Of course, this is good only for limited-run boards: Plugging in a board, programming the chip, and unplugging the board 100 times gets boring very quickly!

    HTH,
    --Rich
     
  5. Shizman

    Thread Starter New Member

    Dec 2, 2008
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    0
    I actually have the Pic2Kit with its sample board, complete with PIC16F already attached. I think that's why I ordered another one, in hopes of being able to make my own board and then solder this new chip onto it.

    Now I'm running into more questions that are difficult to find answers for:

    1. Do I need to put my QFN chip in a socket before attaching it to my own PCB? If not, how do I attach/solder it?

    2. Are the QFN chips really made for machine-soldering methods (i.e. should I just get a pin-based or SOIC IC?)

    3. (Asked already above) How do I cheaply program this darn thing?

    Thanks for any help you can give!
     
  6. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    1. Its better to use a socket because in case the chip burns you can replace it easily. Also, there is a chance to destroy the chip due to overheating while soldering.

    2. Not really, but it is easier to work with DIPs than QFNs.

    3. You can buy a DIP to QFN adaptor as the one you found in ebay.
     
  7. Shizman

    Thread Starter New Member

    Dec 2, 2008
    7
    0
    What socket should I use for the 44-pin QFN chip? Are there specific things I need to look for when shopping for this?

    So the thing I showed you on eBay will allow programming of it? I have a 40-pin programmer, so I assume only a subset of the pins are needed for programming?
     
  8. mik3

    Senior Member

    Feb 4, 2008
    4,846
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    Yes, just a few pins of the chip are used for programming. If you can identify them (datasheet) you can take a simple QFN socket and a few wires as to be able to connect the QFN pins (the ones only needed for programming) to the DIP socket.
     
  9. Shizman

    Thread Starter New Member

    Dec 2, 2008
    7
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    Ahh beautiful. Now, any idea where I can get a socket for this chip? I have tried looking in Digikey, but I have no idea what to look for. Are they called something other than a "socket"?
     
  10. mik3

    Senior Member

    Feb 4, 2008
    4,846
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  11. Shizman

    Thread Starter New Member

    Dec 2, 2008
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  12. RiJoRI

    Well-Known Member

    Aug 15, 2007
    536
    26
    So it actually seems quite simple!

    --Rich
     
  13. bertus

    Administrator

    Apr 5, 2008
    15,649
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  14. Shizman

    Thread Starter New Member

    Dec 2, 2008
    7
    0
    Even better! I found a bunch of sockets on eBay and bought them to make my own programming adapter for my Pic2kit. Those pictures will come in very handy.
     
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