[amsat-bb] Re: YouTube on satellite power management

[Bruce Robertson]

On Thu, Nov 5, 2009 at 8:40 AM, Alan P. Biddle <APBIDDLE at united.net> wrote:
> There is a very interesting video on management of a satellite so as not to
> waste energy transmitting "to whales and penguins."  Not new, but a good
> discussion of the concept and implementation.
>
> http://www.southgatearc.org/news/november2009/satellite_power_saving.htm
>
>
> Alan
> WA4SCA
>

Thanks, Alan --

I'd like to include notes on previous implementations of this idea in
the website, but as a hobbyist, I wasn't able to find info on this.
I'd appreciate any institutional memory folks can offer.

Also, not mentioned in the video is just how easy it is for people to
play with these ideas on their own.

The underlying Plan13 library, as well as the one that stores
keplerian elements in EEPROM, are featured in this video
http://sites.google.com/site/qrptracker/ , at 1:33, we see the
micro-controller run a demo, which is a Predict look-alike.

All the code is open source, published at
http://code.google.com/p/qrptracker/ This is a SVN server, and I'd be
happy to welcome people who'd like write access.

On the hardware side, an Arduino that will run this code (and leave
half of its programming space for further ideas) is available for $20
- $30!

You can't go wrong with this model
http://www.sparkfun.com/commerce/product_info.php?products_id=666
but if you think eventually you'd like to go to a breadboard set-up or
a mini model (which fits nicely in an altoids box so you can hack on
this during your commute :-), I recommend that the USB bridge be
implemented off-board. Just be sure to get an arduino with an
ATMega328 processor. The ATMega168's 16k of program space just isn't
enough to store Plan 13 and do anything with it; whereas, the 328
leaves lots of space, even for a small operating system
http://robotgroup.com.ar/noticias/20091102/duinos-sistema-operativo-multitarea-para-arduino

None of this is meant to be an argument in an Atmel vs. Microchip
debate, since other considerations come into play in the final
hardware choice for inflight micro-controllers. But with C++ libraries
and (pretty well) C code, experiments in this context will be pretty
portable.

Have fun & 73,

Bruce
http://ve9qrp.blogspot.com/