FLEX Support?

[MS3FGX]

Recently came across this project and very happy to see somebody taking up the challenge of getting multimon modernized. Was able to start it right up on my 64bit Mint machine with PulseAudio (so already worlds better than its predecessor).

Was wondering about the possibility of adding FLEX support in the future. As far as I know, there is no Linux software for decoding FLEX, only Windows applications like PDW. Would be nice not to have to run PDW in WINE all the time.

[EliasOenal]

Nice to hear that you like it. Adding FLEX shouldn't be too hard and if someone implements it I will gladly take the patches. I might do it myself, but probably not too soon. To be honest I have so far only verified POCSAG operation, thus the other modes could still have (x64 related) problems.

[MS3FGX]

My mistake, GNU Radio does actually include a FLEX decoder. Of course, having something lighter than GNU Radio to do this would be great.

[EliasOenal]

PDW has since been relicensed as GPL software.
https://github.com/Discriminator/PDW/blob/master/Flex.cpp

[jester-xbmc]

I had a look at using the PDW flex.ccp and creating a patch for multimode-ng, but i'm getting nowhere, are you still looking at implementing FLEX ? it would be a great addition, specially for rasp-pi setups piping rtl_fm
Thanks

P.S. ERMES would also be nice, but FLEX is more used
https://github.com/Discriminator/PDW/blob/master/ermes.cpp

[craigshelley]

Hello,
Back in 2011, I hacked together a FLEX demod for multimon. If I remember, I took some code from gnuradio, but had to write the symbol synchronization and quantization code. I've just rediscovered the code while playing with gnuradio, and thought it ought to be made public. I recall spending a lot of time making it robust to cope with noisy/weak signals etc..
I was just wondering if the project was still alive and if anyone would be interested in the code.
The only snag is that the code is quite a messy hack, and would probably need some tidying up to bring it up to standard.

Regards,
Craig Shelley

[EliasOenal]

I am pretty sure people would appreciate it, since I still get mails once in a while asking me about FLEX support. And while I personally don't have time to play with SDR anymore, I surely still accept pull requests.

[craigshelley]

Ok, I'll try to tidy up the code a bit. I've not had chance to try
multimon-ng yet, I'm hoping it should port across without much
modification.

Regards,
Craig
On 15 May 2015 12:04, "Elias Önal" notifications@github.com wrote:

I am pretty sure people would appreciate it, since I still get mails once
in a while asking me about FLEX support. And while I personally don't have
time to play with SDR anymore, I surely still accept pull requests.

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[jester-xbmc]

Thanks, it will be a most welcome addition.

[boetersep]

https://github.com/boetersep/multimon-ng, works on my pi, p2000 only

[craigshelley]

Flex support added, although not tested with all signal formats.
https://github.com/craigshelley/multimon-ng

[EliasOenal]

If you think it's ready, please send me a pull request. Also I think it would be good to have a small sample, if you can provide any.

[chris021]

Hi Craig, I have tried your fork with flex1600 with out any luck. Would it be possible for me to send you an audio sample?

[craigshelley]

Yes, sure please do. I'd like to get it working on all of the flex
formats.
On 26 Jun 2015 21:15, "chris021" notifications@github.com wrote:

Hi Craig, I have tried your fork with flex1600 with out any luck. Would it
be possible for me to send you an audio sample?

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[chris021]

Here are 2 samples. Both contain a mix of POCSAG and FLEX

https://onedrive.live.com/redir?resid=CE93060699F49335%21147

---

From: Craig Shelley notifications@github.com
Sent: Saturday, 27 June 2015 10:16 a.m.
To: EliasOenal/multimon-ng
Cc: chris021
Subject: Re: [multimon-ng] FLEX Support? (#1)

Yes, sure please do. I'd like to get it working on all of the flex
formats.
On 26 Jun 2015 21:15, "chris021" notifications@github.com wrote:

Hi Craig, I have tried your fork with flex1600 with out any luck. Would it
be possible for me to send you an audio sample?

Reply to this email directly or view it on GitHub
#1 (comment)
.

Reply to this email directly or view it on GitHubhttps://github.com//issues/1#issuecomment-115907098.

[craigshelley]

Hi Chris,

Both files appear to decode ok using the following commands:
$ multimon-ng -a FLEX -t raw paging01.raw
$ multimon-ng -a FLEX -t raw paging02.raw

The output looks like this:
FLEX: 2015-06-27 07:49:08 1600/2/A 00.096 [001234567] ALN THIS IS A TEST
PERIODIC PAGE SEQUENTIAL NUMBER 8251

The other FLEX messages appear to be emergency services pagers, which
I'm a little reluctant to post the decodes of.

paging01.raw contains 6 intelligible bursts of pager activity
1: at 0.2 seconds POCSAG1200
2: at 16.2 seconds FLEX1600/2 (no pages)
3: at 24.2 seconds POCSAG1200
4: at 46.3 seconds FLEX1600/2 (1 page) followed by POCSAG1200
5: at 86.2 seconds FLEX1600/2 (no pages)
6: at 100.6 seconds FLEX1600 (2 pages)

paging02.raw contains 4 intelligible bursts
1: at 5.6 seconds FLEX1600/2 (no pages)
2: at 20.6 seconds POCSAG512
3: at 40.6 seconds POCSAG1200 followed by FLEX1600/2 (2 pages) followed
by FLEX1600/2 (0 pages)
4: at 68.6 seconds POCSAG1200

Regards,
Craig

On Fri, 2015-06-26 at 22:20 -0700, chris021 wrote:

Here are 2 samples. Both contain a mix of POCSAG and FLEX

https://onedrive.live.com/redir?resid=CE93060699F49335%21147

---

From: Craig Shelley notifications@github.com
Sent: Saturday, 27 June 2015 10:16 a.m.
To: EliasOenal/multimon-ng
Cc: chris021
Subject: Re: [multimon-ng] FLEX Support? (#1)

Yes, sure please do. I'd like to get it working on all of the flex
formats.
On 26 Jun 2015 21:15, "chris021" notifications@github.com wrote:

Hi Craig, I have tried your fork with flex1600 with out any luck.
Would it
be possible for me to send you an audio sample?

Reply to this email directly or view it on GitHub

#1 (comment)
.

Reply to this email directly or view it on
GitHubhttps://github.com//issues/1#issuecomment-115907098.

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