Re: [Discuss-gnuradio] Send and Recieve data like "Hello World"

[Tarun Tiwari]

Meenaktchi,

On 7/8/07, Meenaktchi Venkatachalam <address@hidden> wrote:

Thanks Tarun.

 

I am still facing problem with printing the payload as a string. It gets printed as hex thou i use %s or %r. I checked the parameters passed to the callback function in ../gnuradio-core/src/python/gnuradio/blksimpl/pkt.py and payload is converted to a string using to_string() but still when I print payload it gets printed in hex format.

I think you are not unpacking the received payload before printing it. Please go through http://docs.python.org/lib/module-struct.html . I hope this would help you.

Any suggestions?
Thanks for any help
Meenaktchi

Regards,
Tarun

On 7/6/07, Chris Albertson <address@hidden > wrote:

--- Tarun Tiwari < address@hidden > wrote:

> Meenaktchi,
>
> You can pack "Hello World" string as paylaod then use
> send_pkt(payload) on
> the transmiter side. similarly unpack the payload at reciever to
> convert
> into string.
>
> you need to use same formating for pack and unpack at Tx & Rx
> respectively.

Why not implement a mode that is common in the real
world?  Then you can test your receiver by listening
to real signals. No need to have a transmitter working
first

RTTY is the most basic and simple
digital mode possable.  There are no frames
and no packets, no protocol and the data rates
is very low, about 45 characters per second
It is just asynchronous FSK
using two tones 1200 Hz apart.  See
http://en.wikipedia.org/wiki/Radioteletype
The technology is so simple it predates computers

There are many programs for doing RTTY on a PC
under Linux or Windows using just a sound card
So you can download and run an example working
system, get it to work, then duplicate it using
gunradio.

The "hello world" should be the simplest thing
that can still work.  I think RTTY is that.


Chris Albertson
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