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Simple & Useful Project - For your P-Box


Omega-TI

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So you're just going to rely on the socket itself for stability? Might I suggest lengthening the card with empty space in order to reach the front and back slots, like the Rave adapter card in message #3 in this thread. It would seem to be more stable that way.

 

Gazoo

Unfortunately, I can't make the card the correct length, as I'm working in Eagle and thus am under a maximum size restriction of about 3 inches by 4 inches. Also, trimming the board size down makes it cheaper. :)

 

You could probably add some material to it or add a backing of some sort that would reach the slots for stability. I'll think of some ideas.

 

Edit: About the price, the board itself is gonna be $9.63 each to get 3 from OSHPark. I'll have to add up a BOM on Mouser later tonight to figure out how much components will add to that. I will update later.

Edited by gregallenwarner
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Ok, I've calculated my BOM for the speech synth adapter card:

 

 

MAX3000A CPLD    x1 @ $2.93      $2.93
Diodes           x6 @ $0.093     $0.558
Resistors        x9 @ $0.016     $0.114
Ceramic Caps     x7 @ $0.018     $0.126
Tantalum Caps    x6 @ $0.30      $1.80
LM317            x2 @ $0.639     $1.278
LM337            x1 @ $1.36      $1.36
PCB (OSHPark)    x1 @ $9.63      $9.63
---------------------------------------
Total (before shipping)         $17.826
So call it $17.83. There will probably be a small amount I'll have to add to cover the cost of shipping of the components once I place the order, but, depending on how many people commit to one, that shouldn't add more than a dollar to the final cost. Then just tack on the cost of shipping the assembled board to you using your shipping method of choice.

 

Those are the numbers we're looking at. So far, we've got Ω with 1, OLD CS1 with 2, and Iwantgames:) with 1. If anyone else is interested, say the word. I'll wait for a little while to let people respond before I begin this build.

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Ok, I've calculated my BOM for the speech synth adapter card:

 

Those are the numbers we're looking at.

 

 

That's VERY affordable, but... you forgot to add a few bucks to cover your time of assembly and at least a little profit. But yes, a definite +1 on a working unit.

 

An opportunity to get a gadget like this does not come around often, I'm thinking more people will be piling on before too long!

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Those are the numbers we're looking at. So far, we've got Ω with 1, OLD CS1 with 2, and Iwantgames:) with 1. If anyone else is interested, say the word. I'll wait for a little while to let people respond before I begin this build.

I would be interested in one, and be happy to pay for labor too - or happy to get a kit and build myself.

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If you can cover the cost of shipping, I'll ship to Denmark. Though I wouldn't be able to tell you off hand what the cost would be exactly, as I've never calculated it before.

 

I've never actually sold a project of mine yet. Everything I've designed, I've only kept to myself for my own uses. So I don't know what's a reasonable markup for something like this. That's why I just wanted to be as transparent as possible with my BOM so you know exactly what the cost is to me.

 

What is the recommended profit margin that you guys normally charge for your boards? Assembly wouldn't take too long, since it's all surface mount, so I can just reflow it in one step.

 

Also, I feel like my best strategy moving forward would be to start with 3 prototypes using OSHPark. I'd keep one for myself, and send out the other 2 to a couple of people here for testing. Once those two people report back their results, and pending any further tweaks that need to be made to the board, then I can go ahead with a larger production run, perhaps using a more economical board house for cheaper PCB's. Does that sound acceptable to everybody?

 

EDIT: About the kits, if you guys are serious about wanting to do the assembly yourself, I'd be happy to kit one out for you, but be aware, I do most of my designs using surface mount components, and this board, in efforts to make it as small as possible, has a pretty dense component population, so it would be next to impossible to assemble by hand with an iron. I'm set up to do reflow soldering, so I'm happy to assemble these for you, as it only takes about 15 to 20 minutes to do a full board, once I get going.

 

I've been tweaking the design a little, nudging components around, to make things fit a little nicer on there.

Edited by gregallenwarner
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I'd recommend a complete board instead of a kit, unless you're set up to do reflow soldering. Once you've got the setup, surface mount soldering is much faster and easier than doing things by hand.

 

I'm actually using the hot plate reflow method, rather than an oven. I spend a great deal of time researching it before I went ahead with this method, but basically, I have a hot plate that I dedicate solely to soldering (no cooking on this plate! Or else, Mmmmm, lead poisoning!)

 

I use an IR thermometer aimed at the board for constant temperature monitoring. Right now, I use a stopwatch and manually turn the hot plate on and off (Manual PWM!) to manually follow the appropriate heat curve, but eventually I want to automate this with a microcontroller. But aside from that, the method works surprisingly well. Couldn't be easier. (Well, admitedly, an automated oven WOULD be easier! But it's easy enough. I would say, anyone could do it.)

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Since you guys are so interested in this adapter, I figured I'd post an updated screenshot of the board. I've been tweaking it, fixing errors and optimizing the trace layout. I managed to get better thermal management for the voltage regulators by increasing their thermal planes, reduce unnecessary vias, shorten power traces, and generally make everything more tidy. I also noticed a crucial error in the 44-pin edge connector. When I flipped the component around to position it on the top, I guess I inadvertently mirrored it as well, so the pads were on the opposite side of the board from where they should be. (1 and 2 were flipped, 3 & 4, etc.) So I corrected that. I've attached new renderings of the top and bottom sides separately, in case you're interested in seeing the progress.

 

I can easily spend days just optimizing traces. I never feel they're quite right until I've tweaked them into beautiful, optimal paths. If I'm not careful, I might continue optimizing indefinitely! :-) (Don't worry, I think I may be close to perfection for this one!)

post-37498-0-27167700-1411584671_thumb.png

post-37498-0-41867100-1411584676_thumb.png

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Get your name on that board. :)

 

I am PEBless. My goal is to stay that way. This looks pretty cool though..

 

So the PEB with a flex cable card apparantly doesn't just take the lines comming off the expansion port and direct feed some edge connectors. It must be doing some logic considering you cannot just take the speech synth and connect it to the PEB without logic

Edited by slinkeey
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Get your name on that board. :)

Will do. That's usually the last step I take before sending it off to the board house.

 

I am PEBless. My goal is to stay that way. This looks pretty cool though..

Thanks. There's something to be said for going newer and smaller, but I still love my big ol' PEB. :)

 

So the PEB with a flex cable card apparantly doesn't just take the lines comming off the expansion port. It must be doing some logic considering you cannot just take the speech synth and connect it to the PEB without logic

You are correct. The Flex Cable Interface doesn't pass through the SBE (Speech Block Enable) line, and so you must replicate the selection circuitry that exists in the console to generate that line. I've done it in a CPLD, but the resources at the very beginning of this thread show how it's done with discrete logic.
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Very good so far. Rescanning the thread, I've now got this list of interested parties. Let me know if the number by your name is incorrect. And of course, if anyone else hasn't voiced their interest yet, and are wanting one, please let me know. I'll leave it open for a couple more days before I place the order. And by all means, if there's continuing interest after this run, I'll do some more, so don't worry if you miss it.

 

Gary from OPA   1
--- Ω ---       1
OLD CS1         2
Iwantgames:)    2
Ksarul          2
coolio          1
RasmusM         1
Astharot        1
Fritz442        2
ti99userclub    3
Thanks for the interest! I'm glad something I made is of use to somebody!
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