Forum: GNU Radio Fwd: Re: FSK with TX-RX in ISM-band 433 Mhz

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B8e644018d61c5dbd80cc8a00d2e5935?d=identicon&s=25 Luis Simoes (Guest)
on 2006-03-22 17:25
(Received via mailing list)
On Tuesday 21 March 2006 19:15, you wrote:
> > correlator block in according to my needs and build the new block
> > the correlators are working well but the problem can be on the radio
>
> known input data.
>
> Hope that helps,
> Eric

Hi Eric,

thanks a lot. Now I am looking a bit at the code of gmsk2 and gmsk2_pkt.
What
do you think about building the graph this way (without radio part):

gmsk2_demod ----- keep one in N ----- packing ------- file_sink
                            ^^^                      ^^^
                    manchester decoding     pack symbols to bytes

Is oversampling rate (spb) of 2 enough? What is the result of
gr.packe_sink?
Where is the data? I have to implement a preamble detection, is this
possible
with the packet_utils?
The problem is I try to design a receiver for the data format of a MICA2
mote
module and there is no access_code in the packet nor the  payload length
is
512 bytes.
Thanks again,
Luis

-------------------------------------------------------
0dfa1a815559738fc7e0f17b0cbf9e54?d=identicon&s=25 Thomas Schmid (Guest)
on 2006-03-22 20:45
(Received via mailing list)
Hi Luis,

I have the code to decode mica2 motes. It is not perfect yet since I
still use the correlator and I would like to move over to the gmsk way
with proper synchronisation. But it works ;)

In my case, the cc1k sends a synchronisation sequence of 0x999999 to
which I synchronize the correlator. Then, I feed the found softsymbols
into the sos_packet_sink. You have to note that I use SOS as an
operating system on the mica2s. SOS adds a sync sequence just before
the message starts (tinyos does the same). The sos_packet_sink then
finds that sequence in the soft symbols which allows us to get byte
synchronisation. Then, we can look at the packet header and read the
whole message. Once parsed, the messages get added to a msg_queue.
>From the message queue, they get to the registered callback.

Thomas
533e669652a899ecd3b838295aef0837?d=identicon&s=25 Angilberto Muniz Sb (Guest)
on 2006-03-23 00:16
(Received via mailing list)
Can anybody show how to plot from file?

I can capture wbfm to file (modified
capture_to_file.py -- kd7lmo)

I can "play" fm from file (modified nfm_rcv_file.py --
kd7lmo)

Now -- after a capture to file, how do I plot it ?

Thank you,

Angilberto.


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0dfa1a815559738fc7e0f17b0cbf9e54?d=identicon&s=25 Thomas Schmid (Guest)
on 2006-03-23 00:23
(Received via mailing list)
This might help you further:

http://webpages.charter.net/cswiger/plotting.html

Or if you prefere matlab/octave, Dawei Shen's website

http://www.nd.edu/~dshen/GNU/

has an FAQ which gives some information.

Thomas
533e669652a899ecd3b838295aef0837?d=identicon&s=25 Angilberto Muniz Sb (Guest)
on 2006-03-23 03:19
(Received via mailing list)
Thank you, Thomas.

The examples help'd me a lot...
I'm try to "clone" the Python FM implementation into
the Matlab/Simulink enviroment...

Its kind-a-working...

Angilberto.

--- Thomas Schmid <thomas.schmid@gmail.com> wrote:

>
> nfm_rcv_file.py --
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> > Tired of spam?  Yahoo! Mail has the best spam
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> > http://mail.yahoo.com
> >
> >
> > _______________________________________________
> > Discuss-gnuradio mailing list
> > Discuss-gnuradio@gnu.org
> >
>
http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> >
>


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Dc48f9c00e3e6de9640898a531c26d89?d=identicon&s=25 Charles Swiger (Guest)
on 2006-03-23 15:33
(Received via mailing list)
On Wed, 2006-03-22 at 18:18 -0800, Angilberto Muniz Sb wrote:
> --- Thomas Schmid <thomas.schmid@gmail.com> wrote:
> > has an FAQ which gives some information.
One neat trick is to use gnuplot's "splot" function on complex data.
It will actually plot a 3d phasor tip corkscrew that you can drag
around with the mouse and look at from various angles.

--Chuck
B8e644018d61c5dbd80cc8a00d2e5935?d=identicon&s=25 Luis Simoes (Guest)
on 2006-03-24 14:05
(Received via mailing list)
Hi Thomas,

nice to see someone in the gnuradio world treating with the same
problems.
In my case the cc1k send 5 preamble bytes (0x6666) followed by a
synchronisation sequence of 0x9999. After this comes the header and my
data.
The synchronisation sequence of 0x9999 is the chip pattern of
transmition
 what represents a bit pattern of 0x33.
Could you sent me some of your code to see how you realised the
synchronisation detection and the manchester decoding? Did you use bit
padding as in gmsk2?

Thank you in advance,
Luis


-------------------
Luis Simoes
Department of Wireless Networks
RWTH Aachen

On Wednesday 22 March 2006 20:44, you wrote:
> the message starts (tinyos does the same). The sos_packet_sink then
> finds that sequence in the soft symbols which allows us to get byte
> synchronisation. Then, we can look at the packet header and read the
> whole message. Once parsed, the messages get added to a msg_queue.
>
> >From the message queue, they get to the registered callback.
>
> Thomas

-------------------------------------------------------
745d8202ef5a58c1058d0e5395a78f9c?d=identicon&s=25 Eric Blossom (Guest)
on 2006-03-27 20:23
(Received via mailing list)
On Wed, Mar 22, 2006 at 11:44:42AM -0800, Thomas Schmid wrote:
> the message starts (tinyos does the same). The sos_packet_sink then
> finds that sequence in the soft symbols which allows us to get byte
> synchronisation. Then, we can look at the packet header and read the
> whole message. Once parsed, the messages get added to a msg_queue.
> >From the message queue, they get to the registered callback.
>
> Thomas

Thomas,

Can we get this code into the GNU Radio repository?
It's sounds like it's of interest to many.

Eric
B8e644018d61c5dbd80cc8a00d2e5935?d=identicon&s=25 Luis Simoes (Guest)
on 2006-03-27 23:33
(Received via mailing list)
Hi Thomas,

nice to see someone in the gnuradio world treating with the same
problems.
In my case the cc1k send 5 preamble bytes (0x6666) followed by a
synchronisation sequence of 0x9999. After this comes the header and my
data.
The synchronisation sequence of 0x9999 is the chip pattern of
transmition what
represents a bit pattern of 0x33.
Could you sent me some of your code to see how you realised the
synchronisation detection and the manchester decoding? Did you use bit
padding as in gmsk2?

Thank you in advance,
Luis


-------------------
Luis Simoes
Department of Wireless Networks
RWTH Aachen
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