[svlug] semi-offtopic: CCD telescope and Linux

[John Conover]

Akkana Peck writes:
> Florin Andrei writes:
> > For somewhere between $100 and $200, one can purchase a decent telescope 
> > at Fry's. 
> 
> I predict you'll be quite frustrated trying to do imaging with
> a telescope you bought for $200 at Fry's. At least go by Orion
> (on deAnza at McClellan in Cupertino, or http://telescope.com --
> not telescopes.com, which is a different outfit) and take a look
> at what else is available.
> 
> Or join the San Jose Astronomical Association (http://sjaa.net)
> or the Peninsula Astronomical Association
> (http://www.foothill.fhda.edu/ast/pas.htm), both of which have
> loaner programs and public star parties so you can try several
> types of scope and talk to people who use them. (I don't think
> anyone has loaner CCDs, so you'd have to buy or make that part.)
> SJAA's loaner program is a lot bigger and its star parties both
> bigger and more frequent. PAS does have a lot of imagers who would
> probably be happy to talk your ear off about options, though.
>

Wan'a hobby project?

I can't find it on google now, but a couple of years ago, as a
hobby/educational project, someone in one of the photog groups, (and
there was a HOWTO web page,) built a pin hole camera using a
commercially available Samsung CCD which had a Linux interface.

As I remember it, it was a USB file system interface, from Kawasaki
Semiconductor and was used to dump the CCD image to a jpg file in
static RAM, (both devices were commercial units used in digital
cameras.) The USB interface was on the chip, too.

The CCDs in cameras are quite small, about a quarter inch on an edge,
and the mechanics of hooking it to an eye piece doesn't look that
difficult.

Samsung owns about 90% of the digital camera CCD market, (and the US
operations and tech support,) are local in the BA.

Kawasaki owns about 85% of the digital camera CCD interface market,
and the US operations and tech support is on first street in SJ, near
the airport.

The actual algorithm used to convert CCD dump to jpg is quite
involved, (there are aliasing issues, etc.,) and there are about half
a dozen small 10 person companies, (e.g., its a cottage industry,)
that license the algorithms-if you buy the Kawasaki unit, the license
fee is included in the part price. Most of the companies are
ex-Stanford graduates, and are in CA.

I don't know what single unit pricing is, but in large volumes, the
semiconductor BOM for a digital camera runs about $7 for low end units
to $12 for high end units.

One downside, though, is that the pin spacing on the ICs is less than
10 mils, so a breadboard would require a layout, (there is Linux PC
board layout software,) and shuffling it off to an online PC board
maker, which runs about $50 for a couple of boards. Reflowing the
solder for the prototype can be tricky, (but it can be done with a
electronic "blow dryer," if one is careful.)

I don't know if there are commecial units available, (if there isn't,
there should be-and there is probably a market for such a device.)

FWIW ...

     John

-- 

John Conover, conover at rahul.net, http://www.johncon.com/