[Arm-netbook] My little idea...

[Christopher Thomas]

On Tue, Oct 15, 2013 at 8:38 PM, Christopher Havel <laserhawk64 at gmail.com>wrote:

>  Just a little something I cooked up ;) no pictures yet, but here's a wall
> of text about it...
>
> 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. *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.*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.
>
>
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.

http://rhombus-tech.net/community_ideas/carrier_board/

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.


> 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.
>

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.



> 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? ;)
>
> 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!)
>
> 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

http://rhombus-tech.net/community_ideas/micro_engineering_board/
, and it consist entirely of through hole components.

The Second Revision to this board will be going out for prototyping this
week. Pictures and Details to follow this weekend.


> 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...
>
> Any interest at all?
>

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).

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?"

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.

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.

And welcome to the list/world of EOMA and embedded ARM.

Christopher Thomas
Firemoth Industries, LLC - Owner
christopher at firemothindustries.com
cell: 214-458-5990
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