MindStorm122
Posts: 1
Joined: Thu Feb 25, 2016 9:55 am

Re: [HOWTO] Decoding pager transmissions with a Pi and rtl-s

Thu Feb 25, 2016 9:59 am

Hi,
Great post works really well apart from one issue im seeing.

The pager message im receiving is supposed to have the following format
QDAll members please note thatPumper is back in station. LFF Rollinson [STHM]
but when multimong decodes it i receive à and a hard return replacing the right and left square bracket. eg
QDEvening Im looking for a wildfire for a job at in the morning, Ã
DEDMÃ<NUL><NUL>
Any ideas on what could be happening here?

jditcham
Posts: 1
Joined: Mon Apr 22, 2013 11:49 am

Re: [HOWTO] Decoding pager transmissions with a Pi and rtl-s

Mon May 30, 2016 12:38 am

Tadcom wrote:I've done everything like you all described, but I get this output:
Enabled demodulators: POCSAG512 POCSAG1200 POCSAG2400
POCSAG2400: Address: 724320 Function: 0
POCSAG2400: Address: 26267 Function: 3
POCSAG1200: Address: 1901616 Function: 1
POCSAG512: Address: 1837816 Function: 0
POCSAG512: Address: 362826 Function: 1
POCSAG512: Address: 40810 Function: 2
POCSAG1200: Address: 46824 Function: 2


Could you tell me what's wrong? I think that the signal is too weak... :roll:
I know this is an old post but I had the same problem. I'm just letting people know my findings..

I had the blacklist issue too.

I was getting audio but it was scratchy, I knew it wasn't a signal problem because when I plugged the antenna into one of my uniden scanners it was loud and clear. Which pointed to dongle or tuning... I played around trying to adjust the frequency and that didn't seem to make much differency. Then I found this http://davidnelson.me/?p=371 on RTL SDR frequency correction and the magical -p option in rtl_fm ... the audio cleared up and the moment I started piping to multimon I had pager text spewing out beautifully!!

my command line
sudo rlt_fm -M fm -f 148.6375M -s 22050 -o 4 -p 30 | multimon-ng -t raw -a POCSAG1200 -v1 -f alpha /dev/stdin

Now to figure out how to feed filter and feed what I want to my mobile devices!!

Ptyme
Posts: 1
Joined: Sun May 07, 2017 11:29 pm

Re: [HOWTO] Decoding pager transmissions with a Pi and rtl-s

Sun May 07, 2017 11:34 pm

So how did you go filtering what you wanted?

I've finally got it working but need a way to filter cap codes and keys words

Any help would be appreciated.

Ptyme

jditcham wrote:
Tadcom wrote:I've done everything like you all described, but I get this output:
Enabled demodulators: POCSAG512 POCSAG1200 POCSAG2400
POCSAG2400: Address: 724320 Function: 0
POCSAG2400: Address: 26267 Function: 3
POCSAG1200: Address: 1901616 Function: 1
POCSAG512: Address: 1837816 Function: 0
POCSAG512: Address: 362826 Function: 1
POCSAG512: Address: 40810 Function: 2
POCSAG1200: Address: 46824 Function: 2


Could you tell me what's wrong? I think that the signal is too weak... :roll:
I know this is an old post but I had the same problem. I'm just letting people know my findings..

I had the blacklist issue too.

I was getting audio but it was scratchy, I knew it wasn't a signal problem because when I plugged the antenna into one of my uniden scanners it was loud and clear. Which pointed to dongle or tuning... I played around trying to adjust the frequency and that didn't seem to make much differency. Then I found this http://davidnelson.me/?p=371 on RTL SDR frequency correction and the magical -p option in rtl_fm ... the audio cleared up and the moment I started piping to multimon I had pager text spewing out beautifully!!

my command line
sudo rlt_fm -M fm -f 148.6375M -s 22050 -o 4 -p 30 | multimon-ng -t raw -a POCSAG1200 -v1 -f alpha /dev/stdin

Now to figure out how to feed filter and feed what I want to my mobile devices!!

kriskenbe
Posts: 1
Joined: Sun May 28, 2017 5:50 pm

Re: [HOWTO] Decoding pager transmissions with a Pi and rtl-s

Sun May 28, 2017 5:55 pm

I've installed a raspberry pi with a SDR dongle on it and got pocsag working.
But I would like to store the messages in a database, and show these on a website.
I've tried everything above, but can't get it working. Anyone that want to take a look at it?
Oh, i'm not that familiar with Linux :)

Sonny_Jim
Posts: 45
Joined: Tue Oct 23, 2012 4:15 pm

Re: [HOWTO] Decoding pager transmissions with a Pi and rtl-s

Mon May 29, 2017 6:00 am

"Doesn't work" is not a fault report. Please be more descriptive with the problem you are having.

cjk422
Posts: 1
Joined: Fri Dec 15, 2017 9:27 pm

Re: [HOWTO] Decoding pager transmissions with a Pi and rtl-sdr

Fri Dec 15, 2017 9:31 pm

Thanks for the great guide! I'm successfully decoding POCSAG2400 pager transmissions on my Pi.

I'm tuned in to fire/EMS pages. The county send out a LOT of information in these pages sometimes, and I'm constantly getting long transmissions cut off, and it's preceded by the warning:
POCSAG2400: Warning: Message too long
I found the code in multimon-ng/pocsag.c that's generating the warning:

Code: Select all

if (s->l2.pocsag.numnibbles > sizeof(s->l2.pocsag.buffer)*2 - 5) {
  verbprintf(0, "%s: Warning: Message too long\n", s->dem_par->name);
  s->l2.pocsag.state = END_OF_MESSAGE;
break;
}
Looks like it something to do with the buffer size. Is there any way I can increase the buffer size so the messages don't get clipped?

thegearjunkie
Posts: 1
Joined: Thu Jan 04, 2018 12:36 am

Re: [HOWTO] Decoding pager transmissions with a Pi and rtl-sdr

Thu Jan 04, 2018 12:46 am

hi i am a complete noob when i tomes to raspberry pi and i needed some help please
i have successfully setup rtl_sdr, and the possag decoding tools i need but my sdr's are the really old ones and i need to change the ppm of the device i am useing

sudo rtl_fm -A fast -f (myfreqhere)M -M fm -s 22050 -g 44.5 -l 305 | multimon-ng -n -v1 -p -t raw -a POCSAG512 -a POCSAG1200 -f alpha /dev/stdin

it is working great all i need to change is the ppm so i can get on the right freq ?
can anyone please give me a hand ?

Janjorgen
Posts: 1
Joined: Thu Apr 16, 2015 8:04 pm

Re: [HOWTO] Decoding pager transmissions with a Pi and rtl-sdr

Wed Nov 14, 2018 9:49 pm

Hi,

I seem to have a problem with lighttpd.

I have access to /var/www/html/index.lighttpd.html (Placeholder page) @127.0.0.1
But when i try to access a .txt file in the /pager folder through a browser I get: 404 - Not Found.

I have already run:

Code: Select all

sudo chmod 777 /var/www/pager/
Here are my config file:

Code: Select all

server.modules = (
	"mod_access",
	"mod_alias",
	"mod_compress",
 	"mod_redirect",
)

server.document-root        = "/var/www/html"
server.upload-dirs          = ( "/var/cache/lighttpd/uploads" )
server.errorlog             = "/var/log/lighttpd/error.log"
server.pid-file             = "/var/run/lighttpd.pid"
server.username             = "www-data"
server.groupname            = "www-data"
server.port                 = 80


index-file.names            = ( "index.php", "index.html", "index.lighttpd.html" )
url.access-deny             = ( "~", ".inc" )
static-file.exclude-extensions = ( ".php", ".pl", ".fcgi" )

compress.cache-dir          = "/var/cache/lighttpd/compress/"
compress.filetype           = ( "application/javascript", "text/css", "text/html", "text/plain" )

# default listening port for IPv6 falls back to the IPv4 port
include_shell "/usr/share/lighttpd/use-ipv6.pl " + server.port
include_shell "/usr/share/lighttpd/create-mime.assign.pl"
include_shell "/usr/share/lighttpd/include-conf-enabled.pl"


Any ideas? :D

Return to “Other projects”