Noob With Questions...

Discussions related to embedded firmware, driver, and user mode application software development
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drbob
Posts: 39
Joined: Sat Mar 29, 2014 11:22 am

Noob With Questions...

Post by drbob »

I'm new to the SDR world but want to dive in and get dirty...

For me, one of the points of strength of the bladeRF with the HF/VHF extender would be as a potential test platform. As an example, a very useful spectrum analyzer, and SWR meter, and a few other useful RF tools.

As I dig in after receipt of my board(s) I hope to go down the development path to build some of these tools. Other than the docs and information on the Wiki, any other advice?

Bob
drbob
Posts: 39
Joined: Sat Mar 29, 2014 11:22 am

Re: Noob With Questions...

Post by drbob »

I'm pretty excited - received my 115 yesterday, and ordered the 200 today. Looking forward to the arrival of this puppy and making it all 'happen'.

As I contemplate the future of this set of boards, I'm thinking it would be "awesome" to take turn this into a portable service monitor of an opensource variety. Had to lug the 2660 up to the mountain top the last few days and I thought, "wouldn't it be cool if..."? We're still in hicksville, so most of my work is analog lo-band, VHF, UHF since we don't get much of that "fancy stuff" like P25, etc., yet.

As a first step, I'm thinking it would be prudent to compile a list of "wishes" in this project and I'm curious to hear your additional input as potential candidates to add to the list

Watt meter
Spectrum Analyzer
Tone encoding and decoding
2-tone, x-tone sequential
POCSAG encode/decode (just because I have to deal with this routinely)
Rx/Tx testing with calibrated attenuation
SINAD measurements
Tracking generator
CW decode (if we're wishing, why not?)
Cable fault testing
SWR and antenna analyzer

My vision is to build a routed aluminum case with a good seal, and N-connectors for I/O of RF through the case - beef it up and make it relatively industrial so it could be attached to the lid of a laptop for field use.

And when I'm up on Capitol Peak I might even be able to work a little HF while I have lunch... LOL
spcutler
Posts: 28
Joined: Fri Mar 01, 2013 3:12 am

Re: Noob With Questions...

Post by spcutler »

If you need any specific help with POCSAG decoding, shoot me a message and I'll tell you what I can. I have POCSAG (and FLEX) decoding working pretty well with my software SeeDeR.
piranha32
Posts: 26
Joined: Fri Mar 01, 2013 6:25 am

Re: Noob With Questions...

Post by piranha32 »

It's very easy to decode POCSAG transmissions with gqrx and multimon-ng. One thing you have to remember is that multimon expects input sampled at 22050Hz, so you may have to resample the output from gqrx.
The following flow worked well for me on linux:

Code: Select all

#!/bin/bash
nc -4 -v --udp --listen localhost 65530|                                                \
        sox -b 16 -c 1 -e signed-integer -r 48000 -t raw - -r 22050 -t raw  -|          \
        ./multimon-ng -t raw -a POCSAG512 -a POCSAG1200 -a POCSAG2400 -f alpha  -- -
The audio signal was streamed by gqrd over udp to port 65530.
drbob
Posts: 39
Joined: Sat Mar 29, 2014 11:22 am

Re: Noob With Questions...

Post by drbob »

I'm just starting to get my feet wet with this unit (while waiting for my transverter card) and my build is on Windoze currently. I'm going to chat with my programmers about making this a project so I can modularize some of the pieces to call up for various functions.

It's my hope that we (ie, the community experimenting with these puppies) can build some dialog, develop a library of resources, etc., to draw more people into the fold - thereby increasing our knowledge base and contributors to the pool.

As a non-programmer, I find the link between having a blinky-light box and a functional tool that I can explore ideas with is entirely missing for me. (I have a staff, and they love some of my stupid questions at times... LOL) Fortunately, they don't understand much about old-school radio so they keep me around. One day there will be an overthrow and I'll have to turn the business over to younger blood, I'm sure, but until then I get to crack the whip.

I'll post some of my newest questions in one of the other forums tonight (please, no face-palms). :roll:
drbob
Posts: 39
Joined: Sat Mar 29, 2014 11:22 am

Re: Noob With Questions...

Post by drbob »

is there a repository of flowgraphs that people have created for various purposes? Just seemed to make sense that these would get posted, modified, cleaned up, etc., until they were "happy," but I haven't really seen much.
drmpeg
Posts: 62
Joined: Fri Mar 01, 2013 3:58 am
Location: Silicon Valley
Contact:

Re: Noob With Questions...

Post by drmpeg »

argilo has some very nice stuff here.

https://github.com/argilo/sdr-examples

Ron
drbob
Posts: 39
Joined: Sat Mar 29, 2014 11:22 am

Re: Noob With Questions...

Post by drbob »

awesomeness - maybe I'm hoping for the moon, but it would be very "cool" to have a repository of flowgraphs like this that we could all add to and fill out many different solutions to problems - does anyone else see a use for this? If it would be popular, I'd be glad to set up and host it...
drmpeg
Posts: 62
Joined: Fri Mar 01, 2013 3:58 am
Location: Silicon Valley
Contact:

Re: Noob With Questions...

Post by drmpeg »

Github is a pretty attractive place for this kind of stuff. After all, it is software. And of course, it's free.

However, a website that's an index to Github repositories would be cool. Something like:

http://www.rtl-sdr.com/big-list-rtl-sdr ... -software/

Ron
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