Future of Electronics In Aviation

On 2008-06-26, Le Chaud Lapin wrote:
74HC138? You EE too?

No, nothing so grand - merely a hobbyist, although I do some fairly
advanced hobbyist stuff (the current hardware project is an ethernet
card for one of my old 8 bit computers, the hardware is done and works -
all fine pitch SMD on a 4 layer PCB. But the real engineers did all the
hard work packaging a MAC and PHY in a chip, I just had to lay out the
PCB well enough, along with some glue logic and memory).

--
From the sunny Isle of Man.
Yes, the Reply-To email address is valid.

On Jun 26, 11:19*am, Dylan Smith wrote:
On 2008-06-26, Le Chaud Lapin wrote:

74HC138? You EE too?

No, nothing so grand - merely a hobbyist, although I do some fairly
advanced hobbyist stuff (the current hardware project is an ethernet
card for one of my old 8 bit computers, the hardware is done and works -
all fine pitch SMD on a 4 layer PCB. But the real engineers did all the
hard work packaging a MAC and PHY in a chip, I just had to lay out the
PCB well enough, along with some glue logic and memory).

Hah...what a coincindence. I have been reading the 802.11-2007 spec
for past few nights.

I am about to buy this:
http://us.zyxel.com/web/product_fami...No=PDCA2007080
Turns a PC into instant access point, which I will need to recreate a
DHCP-like server for new type of addressing scheme that is different
from IPv4 and IPv6 using a standard PC. Otherwise, would have to hack
WRT54G from Linksys and port my software to Linux or run two Wi-Fi
adapters in ad-hoc mode, which would have worked, but since would have
had to buy an adapter in addition to the one I already have...

Your computer sounds very compact. What are the specs? Which chip?
Zydas? Prism? OS? I am always interesed to see how spartan
requirements get for such devices.

I am particularly interested in knowing the delays for association and
reasociation. I read yesterday:

http://www.smallbusinesscomputing.co...le.php/3600486

...that re-association from one acess point to another by a moving
node can be as low as 68 milliseconds, which is not bad, but
obviously, the lower the better. [This is for MAC/PHY only, not higher
layers like DHCP] I need ultra-low-handover-delay to help solve the
mobility problem in computer networking. I will probably buy 5 of
these dongles, and set them up in a line spaced 100 meters apart, then
walk with laptop in hand and check that a streaming-video session from
hard disk of one of the computers is not broken as laptop moves 500
meters as it associates and reassociates with the 5 pseudo-access-
points.

-Le Chaud Lapin-

Dylan Smith wrote:
On 2008-06-26, Le Chaud Lapin wrote:
He also showed me a miniature camera with 700+x400+ (forget exact
resolution). Cost was about $100. I asked him if such a device could
be mounted on GA aircraft

If it's small duct tape will do as a mounting :-) I've used a similar
camera (it's about the size of a large thing of lipstick, hence is
called a 'lipstick camera') on planes and racing motorcycles.

Some examples (although the quality will be somewhat degraded by
youtube):
http://www.youtube.com/user/74HC138

I also now have a completely self contained camera which cost (in US
money) about $70. Records to an SD card. It's not as good quality as the
lipstick camera, but it weighs only 35 grams and fits on a radio
controlled helicopter.

Could you post a link? One of those would
probably fit inside the wing tiedown eyebolt
on my plane.

On 2008-06-26, Jim Stewart wrote:
Could you post a link? One of those would
probably fit inside the wing tiedown eyebolt
on my plane.

It's called the FlyCamOne - you can probably get one at your nearest
hobby store that deals in RC. Google will find you a supplier on your
side of the world if you want to do it online; all my links for it are
European (I got it from http://www.heliguy.com)

--
From the sunny Isle of Man.
Yes, the Reply-To email address is valid.

On 2008-06-26, Le Chaud Lapin wrote:
Your computer sounds very compact. What are the specs? Which chip?
Zydas? Prism? OS? I am always interesed to see how spartan
requirements get for such devices.

It's wired ethernet (100baseTX and 10baseT autonegotiation) rather than
wireless. The chip is the Wiznet W5100 which is aimed at 8 bit/embedded
applications. It includes a TCP/IP offload engine too - it's a pretty
flexible chip - it gives you the option of using as much of its inbuilt
stuff as you want - you can write your own stack and talk straight to
the MAC, or you can just use its IP layer, or use the whole thing.

The old 8 bit machine it's for is one of these, which were enormously
popular over he

http://en.wikipedia.org/wiki/Zx_spectrum

Quite a lot of the work is software. It's different to write a DHCP
client in Z80 assembler :-)

--
From the sunny Isle of Man.
Yes, the Reply-To email address is valid.