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Newbie SMD

amirbaramamirbaram Posts: 13
edited 2005-11-17 16:15 in General Discussion
I have connected two sx 28AC/DP to a solderless prototype board and would like to try to move to printed circuit using PCB123.com. I would like to use the sx chips with smd connections and am not sure how I would program them. Do I need the printed circuit to have an sx key connection for each chip and only hook up the oscillator after programming the chips. That would seem to take away some of the advantage of the smaller chips because of the space for the sx-key connections.
What is the correct method·for programming an smd chip·on a printed circuit?
Thanks!·

Comments

  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-11-17 15:11
    the programming header doesn't need to take as much space as you think, heres a picture of Bean's SX-Video module:

    sx%20video%20rev%20e.jpg

    the programming header is to the right of the resonator, as you can see it occupies about the same space as the resonator does.

    You could also design an adapter plug to plug the SX-key into that steps the .1 x 4 pin header down to a smaller pitch 4 pin polarized header or socket.

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    ·1+1=10

    Post Edited (Paul Baker) : 11/17/2005 3:15:24 PM GMT
  • BeanBean Posts: 8,129
    edited 2005-11-17 15:43
    If you look at my OSD module picture here http://www.parallax.com/images/prod_jpg/30015.jpg
    You will see that I just left holes for the SX-Key. I just have pins coming out of the SX-Key and connect it to program the SX48 chip.

    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    "SX-Video·Module" Now available from Parallax for only $28.95

    http://www.parallax.com/detail.asp?product_id=30012

    "SX-Video OSD module" Now available from Parallax for only·$49.95
    http://www.parallax.com/detail.asp?product_id=30015

    Product web site: www.sxvm.com

    Those that would give up freedom for security will have neither.
    ·
  • Tony LeylandTony Leyland Posts: 71
    edited 2005-11-17 15:46
    Hi,

    I'd like to ask the following:-

    With this arrangement, I'm I right in assuming that with the Resonator in place, this will not allow the SX-Key /SX-IDE to debug the SX ?
    If this is indeed the case, is it advisable/ok to put maybe a jumper or dip switch to disconnect one of the pins of the resonator,
    to allow debugs to take place ?

    Thanks
    Tony
  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-11-17 16:09
    I believe he placed a socket there for the resonator to allow unplugging for programming, but placing a jumper/switch also will work. Actually Bean how do you program the chip with the resonator smt soldered in place, the traces clearly lead straight to the SX.


    Another method for programming which would require no programming header whatsoever is using a chip clip such as Mouser part #517-923660281 as shown on this page: http://www.mouser.com/catalog/621/1418.pdf·but you would have to wire out the connection in a strain-relief way.


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    ·1+1=10

    Post Edited (Paul Baker) : 11/17/2005 4:13:16 PM GMT
  • BeanBean Posts: 8,129
    edited 2005-11-17 16:13
    You can program with the resonator in place, you just can't debug.
    Bean.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    "SX-Video·Module" Now available from Parallax for only $28.95

    http://www.parallax.com/detail.asp?product_id=30012

    "SX-Video OSD module" Now available from Parallax for only·$49.95
    http://www.parallax.com/detail.asp?product_id=30015

    Product web site: www.sxvm.com

    Those that would give up freedom for security will have neither.
    ·
  • Paul BakerPaul Baker Posts: 6,351
    edited 2005-11-17 16:15
    Gotcha

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    ·1+1=10
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