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GM5: Least-cost USB-MIDI Interface Chip for 4.50 EUR


TK.
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I added myself to the list rather late. I'm 3rd from the bottom. I have not received any invoice yet. am I too late? or will there be another buying opportunity?

It was too late for the first order, but you will get the chance to buy some of the remaining, unpaid chips at 25-08-2008, 8 p.m. CET (see http://www.midibox.org/forum/index.php/topic,11387.msg97347.html#msg97347)

I will start a second order once we reach 250 (or 500) pieces again

Best Regards, Thorsten.

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Mine arrived safe and sound in Singapore.  Thx TK.    ;D

The resistor markings on the PCB silkscreen are kinda strange.  It has R6,R11,R12,R14,R15,R28,R29,R55,R56 and R38.  I saw R56 when I first looked and thought  where are the other 55 going to fit. :o

edit: I see now that the numbers match the schematic.  :P

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edit: I see now that the numbers match the schematic.   :P

I haven't seen the schematic, but it is possibly an extract of a larger design. Sometimes it is easier just to keep the component designators unchanged, for cross referencing, and re-use of parts lists etc.

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Fine :)

Btw: today I sent the remaining paid orders (meanwhile I'm able to prepare ca. 20 mailers per hour ;))

10 Orders haven't been paid yet, the guys got a reminder; deadline is next monday.

Some of you may have noticed, that the postage was lower than expected. The reason is simply, that the weight of some envelopes was lower than 100g. And sometimes the post office lady was so tired of checking the weight, that I got an unexpected discount ;)

And another note: at one day it wasn't possible to get the requested injurance, since I sent the mailers from a smaller post office close to where I'm living.

What I've also learned: PayPal fee is sometimes higher than expected - and I had to pay it. It's different for national/international payments. However, the saved postage compensated the loss.

Here some hints based on my experiences I made in the last days. They could be useful if somebody is planning similar bulk orders in future.

  • By asking the people to send emails with a special syntax in the subject, you can use your email program to trackback orders, money requests, payments and special requests. Also the communication channel is ensured (testing the email filters)
    order_mails.gif

  • Avoid Paypal if possible (e.g. on national money transfers), it saves money. Note that you have to pay the transfer fee!
    order_paypal.gif
  • if Paypal is prefered: request the email address registered at Paypal

  • don't provide different tracking/injurance options, this can drive a post office agent crazy... and the people who are waiting in the queue behind you ;)

  • track the orders in a spreadsheet. Use different colours for "order confirmed", "money received", "mailer sent out".
    order_spreadsheet1.gif

  • By creating cell-references in a second spreadsheet, you can print out the mailer addresses without much effort:
    order_spreadsheet2.gif

However, all these measures saved a lot of time, but they don't completely guarantee that I put the correct quantity of chips and PCBs into the mailer. So, please inform me immediately if you expected more or less parts (my spreadsheet tells me, that the outgoing quantities are still correct)

Best Regards, Thorsten.

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Btw: today I sent the remaining paid orders (meanwhile I'm able to prepare ca. 20 mailers per hour ;))

10 Orders haven't been paid yet, the guys got a reminder; deadline is next monday.

yeh... I know... sometimes common online-banking sucks, and sometimes paypal sucks, and sometimes everything sucks  ::)

money should arrive on time

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Wow, first time in life soldered smt and it worked from the very first second i plugged it in!

generic wxp driver recognized it w/o problems.

Congratulations! What soldering technique did you use? That drag soldering described in this thread looks risky for me as a beginner I think. How hard is it to solder every pin individually in the usual way?

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How hard is it to solder every pin individually in the usual way?

I tried to solder each pin individually and failed. :P (probably possible with smaller soldering tip). After failure I just solder every pin ignoring the bridging, and I removed bridges with soldering wick after I finish soldering. I didn`t use any kind of SMT paste or flux.

Could wick remove too much solder so it left pin unsoldered to the pad? Looks nice and clean but I`m not sure is it properly soldered all the way. I`ll see is it working today if I buy the rest of parts.

EDIT:

@TK

That port naming is very nice! I always wanted to have naming option instead of numeration as you don`t have to remember what is connected where. Good work!

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What soldering technique did you use? How hard is it to solder every pin individually in the usual way?

well i did it individually each one and it gone pretty well; but to ensure it i passed with desoldering wick and removed anything i didn't like.

i used very thin (hmm.. 0.1mm i think? have to check it out later at home) solder and a magnifying glass.

3448_2_jpg156005c5baf40ff51a327f1c34f297

3450_1_jpgf3ccdd27d2000e3f9255a7e3e2c488

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