[hpsdr] HPSDR software direction

[Chris Albertson]

The key is the define interfaces such that after a point the hardware
used is not important.     One way to do this is to have to interface
able to answer queries.  The higher level can ask "what frequency
bands can you tune to?"  "What sample rates can you support?".
Without this the higher level software must be hard coded to specific
hardware.    If you want to leverage those 7,600 SR40 users then you
have to write software they can use

I don't see any reason at all to standardize on a programming language
or GUI toolkit.   Mostly programs can be self contained and if two
need to "talk" that can do so over sockets.   The interfaces need to
be as "over the wire".

Interfaces are easy to design if all you want is a software emulation
of a 1980's HF radio.  But today with SDR we can do so much more.  For
example if you are going to decode FSK why convert it to audio first?
A modern SDR can and should be able to decode and maintain a
transcript of EVERY signal in the band.  30 years ago we needed a
hardware filter to select a portion of the IF.  Today we can have
1,000 filters running simultaneously inside a computer.     What I'm
getting at here is that an interface needs to allow M:N connections.
This means if a class-x object can talk to a class-y object you have
to allow that there could be any number of x and y objects in the
system.   each can be queried for limits like bandwidth or frequency.
  with many of them you also need an ability to search and select.
This is not hard to do.  You model the interface on a group of people,
when one shots out "anyone here speak French?", most will ignore you
but one or five might say "Yes".  You have a set of objects, each can
describe itself and knows when it's name is called and can say "I'm
here".

When you have a software system like that it is very easy to expand it
with new features.  Also and I think this is key, a new developer does
not need to know much about how the existing code works.  He can add a
new kind of graphics windows display or add support for new SDR
hardware without knowing how other parts of the system work.

So don't think of an interface as a pipe that connect two objects.
think of it as a "radio net" that connects a set of operators.

++++++++++++++++++
easy for the Softrock40 camp to use and contibute to as well. There
are many on this list who I am sure who also have a toe in that camp
too. There are nearly 7700 people on that Yahhoo list, so there is a
large user/experimenter base there.
-- 
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Chris Albertson
Redondo Beach, California

 1280966423.0