Re: [Discuss-gnuradio] Using Header/Payload Demux

[chris 0]

Hi Martin,

Thanks a lot for all your help!  I just added the CRC checker, and it works perfectly!

I'd never have been able to figure that out by myself.

Kind Regards

Chris

On Mon, Jan 27, 2014 at 8:12 AM, Martin Braun <address@hidden> wrote:

On 01/25/2014 09:30 PM, chris 0 wrote:
> Tag Debug: Rx Bytes
> Input Stream: 00
>   Offset: 0  Source: n/a     Key: packet_len   Value: 14
>   Offset: 0  Source: n/a     Key: packet_num   Value: 0
>   Offset: 1  Source: n/a     Key: packet_num   Value: 1
>   Offset: 1  Source: n/a     Key: packet_len   Value: 112
>   Offset: 3  Source: n/a     Key: packet_num   Value: 2
>   Offset: 3  Source: n/a     Key: packet_len   Value: 112
>   Offset: 5  Source: n/a     Key: packet_num   Value: 3
>   Offset: 5  Source: n/a     Key: packet_len   Value: 112
>   Offset: 7  Source: n/a     Key: packet_num   Value: 4
>   Offset: 7  Source: n/a     Key: packet_len   Value: 112
>   Offset: 8  Source: n/a     Key: packet_num   Value: 5
>   Offset: 8  Source: n/a     Key: packet_len   Value: 112
>   Offset: 10  Source: n/a     Key: packet_num   Value: 6
>   Offset: 10  Source: n/a     Key: packet_len   Value: 112
>   Offset: 12  Source: n/a     Key: packet_num   Value: 7
>   Offset: 12  Source: n/a     Key: packet_len   Value: 112
>
> For some reason the first packet_len is still 14, rather than 112, which
> is confusing me.

Hi Chris,

this is, in fact, correct behaviour.
HPD -> All lengths are 14
Multiply tag -> All lengths are 112
Repacker -> Finds first tag, uses that for processing and scales it
back. You can test this by adding more tag debugs.

An easy solution would be to pipe the OUTPUT of the initial repacker
into both the header generator and the payload modulator. This way the
number of symbols gets coded into the header. Note that this length is
also used in the HPD to slice the payload out of the rx'd stream.

See: http://i.imgur.com/1ciVDjM.png

I'm beginning to realize that maybe the default header generator needs a
scaling value as well. *sigh*

MB

_______________________________________________
Discuss-gnuradio mailing list
address@hidden
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio