<div dir="ltr"><br><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Oct 15, 2013 at 8:38 PM, Christopher Havel <span dir="ltr"><<a href="mailto:laserhawk64@gmail.com" target="_blank">laserhawk64@gmail.com</a>></span> wrote:<br>
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Just a little something I cooked up ;) no pictures yet, but here's a
wall of text about it...<br>
<br>
I've got hand drawn schematics made up for an EOMA-68... er... I'm
calling it a Carrier Board for now (the PCB that the CPU card goes
into). This one uses only through-hole components, and all but two
(the PCMCIA slot and, oddly enough, the Ethernet jack) are very
cheap. The idea is that someone like me who is rather a bit of a
dunce with the soldering iron can still put it together in a
dedicated weekend, if so inclined. <b>That is, a person with fairly
beginner-level hobby skills can buy a fistful of parts and a CPU
Card, etch a PCB (or get one from somewhere) and after a few hours
of lead fume inhalation, has a complete computer in their hands.</b>
That's a huge gift, I think, to the Maker community, not to mention
the technically-inclined poor folk out there (I *know* I'm not the
only one!)... seriously, it sounds like good stuff to me.<br>
<br></div></blockquote><div><br></div><div>With the exception of the Through Hole components, we're right there with you... here was my idea I am currently in the process of building right now. </div><div><br></div>
<div><a href="http://rhombus-tech.net/community_ideas/carrier_board/">http://rhombus-tech.net/community_ideas/carrier_board/</a></div><div><br></div><div>Regarding the Ethernet component, I have a Gigabit Ethernet jack that has magnetics and is through hole that is only $3. Also, I have a Hirose PCMCIA connector that is ALSO very cheap ($3.69), and is through hole as well. ALSO, it can be had for free from "NeedASample.com". The board I mentioned above will be listed as opensource and free to download and modify.</div>
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My two rules for designing were (1) no surface mount anything at all
period end-of-story, and (2) use as many very standard parts as
possible. Every component can be had at Mouser Electronics in single
unit quantities.<br></div></blockquote><div><br></div><div>My consideration to this would be, while Through Hole is definitely easy, SMD is ALSO easy (within reason), it is only perceived as complicated due to the size differences. SMD components aren't necessarily more fragile, and they are certainly manageable for the common person. I have taught several high school classes and freshman college courses on SMD soldering by hand with commonly available tools. My most common recommendations, 1) Clean TIP, 2) Flux, 3) Steady but abundant heat availability. Also, if soldering SMD, for passive components, it's easier to stay within the 0805-1206 range, and TQFP/SOICS, QFN and BGA ARE doable by moderate-average skilled people, but just require more patience.</div>
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The Ethernet jack has the magnetics built in, so it's
(unfortunately) the most expensive part on the board -- but I
couldn't find a through-hole Ethernet transformer... I've probably
also omitted some necessary things out of simple ignorance (I have a
hunch that there's more to the USB connection than four wires, a
power supply and data feed, and the connector itself, for instance).
I'm more budding hobbyist with this stuff than anything else -- but
hey, you gotta start somewhere, right? ;)<br>
<br>
The only thing I don't like is that it still requires a custom PCB
unless one wants to do some very creative dongle-making... probably
doable but it'll be very ugly in a number of ways. That said, I'll
be quite surprised if this design cannot get away with using a
single-sided PCB -- meaning any shmuck who can get to eBay can order
the supplies to make the board at home if they want to. (Sounds a
little like me!)<br>
<br></div></blockquote><div>Most boards that require high current, or impedance matching will need to be 2 layer at a minimum, and 4 layer is recommended for the larger component counts. A simple carrier board like you are describing has already been made</div>
<div><br></div><div><a href="http://rhombus-tech.net/community_ideas/micro_engineering_board/">http://rhombus-tech.net/community_ideas/micro_engineering_board/</a></div><div>, and it consist entirely of through hole components. </div>
<div><br></div><div>The Second Revision to this board will be going out for prototyping this week. Pictures and Details to follow this weekend. </div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
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If anyone wants to try reading my horrible chicken scratch I'll send
out a link to a scanned copy, otherwise I'll try and work up the
motivation to move it into my graphics software (CorelDRAW X3),
since, although I have a copy of Kicad, I never really bothered to
learn how to use it properly...<br>
<br>
Any interest at all?<br></div></blockquote><div><br></div><div>There is TONS of interest, and the market is there. My company, and others, will be releasing several iterations very soon, all open source, and easy to purchase, build, or assemble. They will be easy to send to places like BatchPCB, SeeedStudio, or even your local hackerspace (for those that can do 2 layer etching). </div>
<div><br></div><div>I have given 3 Presentations in the last 2 weeks, they have all been received with very warm and interested queries, with things like "Do you know what I could use this for?! When can I buy it? Can I have this sample?! How many can you sell me?" </div>
<div><br></div><div>Your ideas are very much welcomed, and if you like, I, or any number of people on here, would be more than happy to look at what you've got. Or you can post images to imgur and include the links via a new topic thread to let everyone see. </div>
<div><br></div><div>And if you have any questions, please feel free to call or email me any time, or post a question to the list, and someone should get back to you shortly. </div></div><div class="gmail_extra"><br></div>
And welcome to the list/world of EOMA and embedded ARM.</div><div class="gmail_extra"><br><div dir="ltr"><div style="font-family:arial;font-size:small">Christopher Thomas</div><div style="font-family:arial;font-size:small">
Firemoth Industries, LLC - Owner</div><div style="font-family:arial;font-size:small"><a href="mailto:christopher@firemothindustries.com" target="_blank">christopher@firemothindustries.com</a></div><div style="font-family:arial;font-size:small">
<span title="Call with Google Voice">cell: 214-458-5990</span></div></div>
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