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circuit fabrication

Lee MarshallLee Marshall Posts: 106
edited 2007-10-14 18:52 in Propeller 1
after reading a prop 2 thread, specifcally the part about it being in a qfn/plcc package.
I use tripad board for building circuits(like stripboard, but with the strips grouped into 3 holes). PLCC would be bad enough(confusing socket pinout), but qfp/qfn with a very high pin count could make things very awkward for hobbyists like myself. the only solution i can think of is to get one of those REALLY expensive QFP ZIF sockets, but im a little tight on cash for that.

I'd appreciate any advice as to how to connect the prop II when it is released without resorting to getting PCBs made(too much time/money), such as another circuit fabrication technique.
how does everyone else expect to wire it in?
Ive heard of something about using a wiring pen with polyurethane enameled wire, would trying this do me any favours?

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-Confucius

Comments

  • hippyhippy Posts: 1,981
    edited 2007-10-12 15:48
    From previous discussions, Parallax are aware of the problems faced by hobbyists and home constructors and I believe a proposed intention is to deliver a plug-in solution ( like the Spin Stamp ) which will help in that respect. If Parallax do not offer a solution then I am sure others will step into the arena. It should be possible to also obtain QFP/QFN and PLCC breakout boards form existing manufacturers.
  • Ken PetersonKen Peterson Posts: 806
    edited 2007-10-12 18:21
    General purpose QFP breakout boards tend to be rather expensive from what I've seen. However, in large enough quantities, it wouldn't be expensive to custom make a PCB. Check out www.expresspcb.com . You can get three double-sided 2.5" x 3.8" boards for $51, and the design software is a free download. You could probably make two or three breakout boards with each of those by cutting them apart after they are made.

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    The more I know, the more I know I don't know.· Is this what they call Wisdom?
  • Graham StablerGraham Stabler Posts: 2,510
    edited 2007-10-12 18:39
    I'm hoping the first propII product is a protoboard with appropriate pricing, that will keep me happy for a while.
  • Lee MarshallLee Marshall Posts: 106
    edited 2007-10-12 19:28
    You said...
    You can get three double-sided 2.5" x 3.8" boards for $51, and the design software is a free download.

    good suggestion, unfortunately, shipping to scotland brings the deal to around £42($84), which is more than i would like to(can) spend on some adaptor boards.
    then again, maybe i will have finished school and have my own house/big high paying job(Microprocessor Design Engineerscool.gif) by the time the prop II comes out.
    btw: have we got a proposed date for release of the prop 2?

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    -Confucius

    Post Edited (Mr Crowley) : 10/12/2007 7:35:33 PM GMT
  • grasshoppergrasshopper Posts: 438
    edited 2007-10-12 19:44
    You could make your own PCB board for $33.00 at advanced circuits it would be considered a prototype. I have had great results from them and they have free software available. I have never used the program but the tools are available.

    www/4pcb.com
  • Graham StablerGraham Stabler Posts: 2,510
    edited 2007-10-12 19:50
    Even with a pcb soldering the thing reliably by hand will be tricky, I suspect WHEN the prop II comes out so will a variety of solutions, I'd worry about it then, I suspect it will be a while. Plenty of time to become a zen master in the propI.
  • grasshoppergrasshopper Posts: 438
    edited 2007-10-12 21:25
    My apologies i forgot that some are a bit new or at least shy, in the soldering department. I solder smd parts every day and i often forget that others are still soldering DIP components. I guess you can wait, but i am designing a board as i type this to accommodate the Propeller and its supporting devices. I could make 1 for you all you pay is cost.
  • IAN STROMEIAN STROME Posts: 49
    edited 2007-10-13 00:05
    Hi Lee,
    Check out Qbis Electronics on Ebay
    stores.ebay.pl/Qbis-Electronics
    I got 4, 24 to 152 pin PQFP adaptors for 9 quid
    including postage to Scotland!!
    Quick service < a week.


    Best Regards
    Ian

    :- Anything you buy, will be in the sale next week.
  • DroneDrone Posts: 433
    edited 2007-10-13 03:18
    Flip the part over & glue it to a piece of perf-board. Then solder one or more 0.1" header(s) on the perf-board and use wire-wrap wire to attach to the 0.1" header pins. Lastly, solder the other end of the wire-wrap leads to the pads on the upside-down part.

    The resulting break-out board will plug into 0.1" prototyping boards. Use a low-wattage iron on the SMT part, I use a variable temperature 6W iron with a sub-mm tip. I know it's a kludge, but it works... and it's cheap (forgetting about the cost of labor).

    David
  • Lee MarshallLee Marshall Posts: 106
    edited 2007-10-13 03:47
    hmm, i was considering learning about wire wrapping, i hav a variable temp 50W iron jumpin.gif, wrapping tools from my main "supplier"(farnell UK) are costly though, the cheapest i can find is:
    uk.farnell.com/jsp/search/productdetail.jsp?sku=441089
    and thats £22.30(around $44), obviously a rip-off, as they r sellin them for $6.99 at radioshack.

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    I hear and I forget. I see and I remember. I do and I understand
    -Confucius
  • peterzpeterz Posts: 59
    edited 2007-10-13 09:21
    There is at least one express pcb manufacturer in Europe. Some time ago someone asked for it in this forum and someone gave the internet address of a·pcb·manufacturer in Europe that works that way: small series, fast and cheap! It did not have software tools however, only the pcb service.

    I have tried to find that post on the forums but I have been unable to find anything. Does the search engine work at all?
  • mirrormirror Posts: 322
    edited 2007-10-13 11:07
    I was searching for a same PCB manufacturer (I think) on the forum a couple of weeks ago, and also failed. Then I remembered that I got them to send me an email. Only 1 problem. The manufacturer is in China, not Europe. The adress is : www.pcbcart.com. There might have been a European manufacturer mentioned in the same message thread, if I could find it.

    Sometimes the search engine works - I have found stuff before, but this forum seem to be growing at a frightening rate. I used to read all the posts (propeller only) - I now skip lots as I don't have the time to read them all.

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  • evanhevanh Posts: 16,076
    edited 2007-10-13 11:31
    If you only want small volumes for the moment then Yellow Pages is your friend. Even moderate sized cities will have one or two PCB makers. Get a tour around the plant. [noparse]:)[/noparse]
  • LeonLeon Posts: 7,620
    edited 2007-10-14 14:40
    I mostly use PCB-Pool for prototypes:

    http://www.pcb-pool.com

    The quality is excellent and prices are quite reasonable.

    Leon


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  • DroneDrone Posts: 433
    edited 2007-10-14 18:52
    Advanced Circuts has recently recleased an EDA suite (schematic capture, layout, autorouter, etc.) program that is seemingly Free and not hindered (reports are it can save Gerber's dunno about Exc drills). Link www.pcbartist.com/

    David
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