Our digital video signal is on the air!
John Pritchard
First question..
What was or could have been the internet centric way to move from vega to pc164 (@oz7sat)?
- relocate usrp, plug cables, etc
- install gnu radio
- ?download something?
- (then, pipe gstreamer into gnu radio)
To receive the signal via USRP one would do the same?
- (then, pipe radio to gstreamer)
http://en.wikipedia.org/wiki/23-centimeter_band
http://en.wikipedia.org/wiki/Amateur_television
Alex Csete
> http://twitter.com/csete/status/19672913053
We did get on that air and had stable video link for more than 30
minutes, after which the receiver computer was running out of battery
http://twitpic.com/298axs
>
> First question..
> What was or could have been the internet centric way to move from vega to
> pc164 (@oz7sat)?
>
> relocate usrp, plug cables, etc
> install gnu radio
> ?download something?
> (then, pipe gstreamer into gnu radio)
Not sure I understand the question... One can insert internet link
anywhere in the pipeline on both receiver and transmitter, e.g. have
one computer do the video capturing and processing and another do the
software radio thing and link them with TCP, UDP, RTP, ... So you can
stream your webcam from the US using RTP to me and I can put it on the
air if you want ;-)
For this concept setup, the whole transmitter part (capturing,
encoding, software radio TX) was running on a single computer as was
the receiver. The TX computer is a new laptop with intel i7 quad core
processor. It could do the encoding and software radio TX without
sweating: http://twitpic.com/298ixb
The RX computer was my old laptop, which is not much faster than a
modern netbook http://twitpic.com/298axs
>
> Second question..
> To receive the signal via USRP one would do the same?
>
> (then, pipe radio to gstreamer)
Yes, see attached "design document" ;-)
I will write this up with proper description next week.
This week I'm busy preparing for the AMSAT UK colloquium.
Alex
John Pritchard
This week I'm busy preparing for the AMSAT UK colloquium.
Can't wait :)
Alex Csete
>
>>
>> This week I'm busy preparing for the AMSAT UK colloquium.
>>
>
> Can't wait :)
I've put the slides and videos on slideshare:
http://www.slideshare.net/csete/gnu-radio-and-the-universal-software-radio-peripheral-4889786
The video recording should also be available soon.
Joshua
John Pritchard
i'm wondering if a $300 USRP is possible
very well!
--
http://www.google.com/profiles/john.douglas.pritchard
Alex Csete
sell 200k units which would cut the per unit manufacturing costs). You
can look at similar products - I doubt you'll find many for less than
$10k.
You can of course try something smaller, but you will always have very
high costs developing the prototypes, probably no less than $50k even
when you have a reference design. You'll have to sell many $300 units
to get the initial investment back.
Did you see the presentation by Howard Long G6LVB? That little £100
USB dongle receiver they are developing is only possible because they
use commercially available DVB SOCs; however, in order to get the
technical specs for those you need to sign all sorts of NDA papers so
it can't be used for open source.
Alex
> --
> http://groups.google.com/group/ultra-light-space-flight?hl=en
>
John Pritchard
You can of course try something smaller, but you will always have very
high costs developing the prototypes, probably no less than $50k even
when you have a reference design.
Made me think about the simulation of energy propagation and radiation in electronics. I suppose this is the problem? Wonder if my ham course will take me there.
Guess I'll stick to a mostly analog outlook for the moment.
Alex Csete
>
>> You can of course try something smaller, but you will always have very
>> high costs developing the prototypes, probably no less than $50k even
>> when you have a reference design.
>>
>
> Made me think about the simulation of energy propagation and radiation in
> electronics. I suppose this is the problem?
The problem is that building and making physical things work requires
time and material.
It's like writing and publishing a book, i.e. the cost of the first
printed copy vs. the cost per book if you print thousands.
> Wonder if my ham course will take me there.
I think your ham course will teach you how to safely connect an
antenna to a transmitter without getting electrocuted and what to do
to prevent interference between different users of the RF spectrum.
Simulation of energy propagation and radiation in electronics sounds
more like a topic for post graduate R&D in electrical engineering or
physics.
John Pritchard
omg lol