Ekko,
Are you trying to test this out initially over the air? If so, you may consider just running this through a script to itself without going over the air. This would remove all possibility for interference and environmental black magic.
As far as testing what I am talking about, start by simply adding bytes to the file you are trying to send. White space, or a specific character, or whatever you want. Run this through the system. Once you add enough extra bytes, you will eventually see your entire wanted data.
This is not a good final solution however. With this you will run into a problem sending multiple things back to back and you will have to deal with the packetizer input buffer on the TX side holding onto the extra added bytes and prepending them onto the next thing you want to transmit.
The better solution would be to do what Marcus suggested. This would be adding something before the packet encoder step that will ensure the data moving through the system has enough bytes for the packet encoder to do what it needs to. This is up to you as how and where to implement, but the bottom line you need to be aware of is the number of bytes that are required to generate a chunk of packets and that your data needs to be an exact multiple of this number.
Hope this is helpful,
Michael
From: Ekko [mailto:address@hidden
Sent: Thursday, January 07, 2016 5:13 AM
To: Michael Berman <address@hidden>
Cc: address@hidden
Subject: Re: [Discuss-gnuradio] how to send a complete file
hello Michael
as you said,there are not enough data to feed the packetizer ,
now i use the dest file(generated by the same grc) as the source ,
1--->i think that the dest is generated by the grc,so the data in dest file must can feed the packetier, is it right
when i use dest file (generated by the same grc,now called A) as source file,to run my grc ,i got a new dest file (called B)
i campare the data in A and B
there is also some data lost. if my guess no.1 aboved is right ,
the data lost may not be caused by （ there was not enough data in the file to feed the packetizer）
hope for your correct.
thank you
--Ekko
2016-01-07 2:26 GMT+08:00 Michael Berman <address@hidden>:
Ekko,
It has been a while since I have dealt with this kind of issue with the digital coms, but I have run into this. The problem I found was that there was not enough data in the file to feed the packetizer properly. There are probably several work arounds for this, but the simplest would be to pad the data up to the exact amount the packetizer needs to generate the packets and send them along. You can check if this is the case by varying the size of your file. If you change the number of bytes in the file, you should see the amount left out varying; if you add bytes slowly you should see a breakover point near a multiple of the number of bits the packetizer needs that will create a small or no amount of data not transmitted.
Michael
From: discuss-gnuradio-bounces+mrberman87=address@hidden [mailto:discuss-gnuradio-bounces+mrberman87=address@hidden] On Behalf Of Ekko
Sent: Wednesday, January 06, 2016 9:01 AM
To: address@hidden
Subject: [Discuss-gnuradio] how to send a complete file
hello
I'm using gnuradio to simulation the gmsk tx/rx with a file
this is my grc
you can see ,i am using a file_sink and file_source,
the file_source is set to not repeat,i want to send this file ony one time.
and my source file‘s size is 140KB
after i run this grc (i am sure the send is stop )
i check the dest file,the size of whitch is 139.3KB
then i compare two file
just like
we can see that some data is lost(exactly 22 lines)，
so i want to know how can i send a complete file, just i send 140KB,and recieved 140KB,
then stop.
thank you
-Ekko
