[MLB-WIRELESS] Mast mounted wish list

[Lyndon David]

I was having a think about what would be in my ideal device for rolling out
a wireless mesh. I was thinking about the possibility of designing one as I
used to be an embedded systems hardware designer. Unfortunately time is
against me as I am too busy and then I am emigrating from the UK to
Castlemaine.

I was thinking that the ideal device would:

Be small enough that it can be mounted in a waterproof box. PC104 standard
board size comes to mind.
It would have one radio and one ethernet.
Have the RF connector mounted in the top of the box so that you can screw a
small omni directly to the top of the unit without having to use any
expensive LMR cable.
Very low power consumption so that no fans are needed. Also good if you need
to Solar power it.
Run from a single DC power supply from say 6v to 20v
If it is going to be run from mains power then use power over Ethernet so
that only one cable needs to be run to it.
1 serial port for development and debug use.
1 PCMCIA or mini PCI for the radio card.
Processor core: Several choices available, if it was x86 based then would be
capable of running one of the many embedded distributions without having to
get out the cross compiler. This is probably not a big deal as if there is
good hardware available someone will distribute the software built for that
platform.
16 to 32 Mb of non volitile memory. Preferably this would be on board for
least system cost.
64 to 128 Mb RAM preferably on board.
Industrial extended temperature range (-40 to +85 C) as this thing will be
up a pole anywhere from Australia to Norway. Dont think I have ever seen a
wireless card with this temp spec.
It would be really good if the wireless components could be on the board but
the certification process would be out of order.

Things we dont need. Video, sound, keyboard, USB, printer port etc etc.

So I had a look around to see what was happening.


www.soekris.com
Good board at a good price. Lots of functionality.

Lots of industrial control boards in PC104 format. They cost how much !!
Bloody hell.

LART board www.lart.tudelft.nl
Open source hardware. Would need some small modifications. Junk the
expansion connectors that are on the board and wire up a mini PCI instead.
Add Ethernet.
This board has some really good ideas. I particularly liked the way you can
program the flash from the JTAG port (explanation of JTAG at end) so that
you dont need a BIOS or PROM programmer etc.

Open brick www.openbrick.org
Open source hardware platform for thin clients. The price is not good. Now
we have VIA mini ITX boards at a fraction of the cost.

mini ITX motherboards.
Very cheap, small, no fans if using VIA Eden processor. Add an IDE to CF
converter for no moving parts. Power supply is a bit of a pain as it runs
from an ATX supply. Not ideal for headless operation unless the BIOS can be
told to redirect to the serial port. (have not read the manual)

Take a commercial access point, pull it out of the case and put it in the
waterproof enclosure and load your favorite software into it instead of the
commercial software it came with.

Are there any others ?

JTAG - is a test interface that is covered by an IEEE spec. It is used at
the end of the manufacturing line to test the board. One of the things you
can do with it is disconnect the processor core from the I/O pins and
"manually" drive the output pins into any state you want. You can interface
to the JTAG port using a little bit of logic and the parallel port from your
PC. The LART board uses this to bypass the processor and load boot code,
kernel and initrd image into the flash. The hardware and software to do it
are on their site.

I quickly came to the conclusion that:

You will not find the components in your local Dick Smith
Because of the itty bitty surface mount components making your own from a
kit of part will be at the very hard end of DIY electronics and is not
practical for the majority of us. Therefore it will need to be manufactured.
You need to make lots of them if this is not going to be rediculasly
expensive.

At the moment it would seem that there are no products that I can find that
match all of the wish list. The soekris board probably comes closest.

Anyone here own an electronics manufacturing line ?

Lyndon

PS I have been looking at Australian ISPs and they charge by the Mb. What
the F*** is that about ?



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