Java program to decode DMR

[dtscho]

I've checked lots of times to make sure line-in is not muted. I'm not sure about it being "selected" - I think if something is plugged in to line-in, the computer will use it. I'll go back and re-check.

Couple of other questions:

I've tried both the mic and line-in jacks. Should I only be trying to get this to work with line-in? (Just trying to rule things out to isolate the problem.)

The PSR-800 puts out stereo audio through its headphone jack. My cable is mono. I know this shouldn't matter, but maybe there's some kind of problem there?

Will keep working on it. Thanks to everyone for the assistance.

Dave

 

[IanWraith]

Hi

Yes if you have a line in then stick to using that although the program accepts its audio input whatever the Operating System has decided is the designated audio source. In theory Windows "should" select a newly plugged in source but that isn't always the case.

Ian

 

[313RADIO]

ian thanks for dmrdecoded it works great! i dont know much about dmrs technicial detals, but i am wondering if there is a way to identify what system a certian frequency belongs to? i dont think theres a traditional control channel right? is there any system or tower info encoded into the data stream? i have a few trunked systems nearby, but im not sure whats what, fcc info is somewhat confusing, as i am hearing analog comms on some of there freqs. thanks

 

[IanWraith]

Hello

Glad you like the program. In answer to your question no DMR doesn't transmit anything (such as a system ident) to help you ID a system sadly which is a bit of a pain. There are different types of DMR systems out there also which makes this more complex. Being from the UK I can't help you with the FCC info but I'm sure there will be someone on here who can.

Regards

Ian

 

[wa6yvx]

Decoding DMR Bitstream

Has anyone made up a chart showing which bits are what? Sometimes I don't always get ID's displayed
(Source or Group), but I do get the 1's and 0's.

 

[313RADIO]

Ok thanks for thre reply. lets say if i see "rest LCN is LCN 8" or something to this effect, can i assume there are 8 active trunking channels?

 

[dtscho]

I've checked lots of times to make sure line-in is not muted. I'm not sure about it being "selected" - I think if something is plugged in to line-in, the computer will use it. I'll go back and re-check.

Couple of other questions:

I've tried both the mic and line-in jacks. Should I only be trying to get this to work with line-in? (Just trying to rule things out to isolate the problem.)

The PSR-800 puts out stereo audio through its headphone jack. My cable is mono. I know this shouldn't matter, but maybe there's some kind of problem there?

Will keep working on it. Thanks to everyone for the assistance.

Dave

Well, I finally got the PSR-800 to communicate with the computer. I had to use the mic-in port (line-in didn't work) and turn the volume way up on the scanner and the mic-in port. Even though I got some sync, it didn't really decode much of anything. I only got one color code while monitoring for a while, and I had error rates of 35-40%. I guess it's a volume problem, but I've got everything turned up. And the IF output volume being at "MAX" on the PSR-800 really eats the batteries.

Dave

 

[IanWraith]

Hi

Has anyone made up a chart showing which bits are what? Sometimes I don't always get ID's displayed
(Source or Group), but I do get the 1's and 0's.

Not all DMR frames contain any radio or group idents. If the program displays binary it is because either ..

1) It doesn't yet decode that type of frame for example the data transfer type frames.

2) The frame it has received isn't defined in the ETSI DMR standard and is manufacturer specific. We have worked out the meaning of the Capacity Plus ones but there are still plenty more to work out.

Regards

Ian

 

[IanWraith]

Hi

Well, I finally got the PSR-800 to communicate with the computer. I had to use the mic-in port (line-in didn't work) and turn the volume way up on the scanner and the mic-in port. Even though I got some sync, it didn't really decode much of anything. I only got one color code while monitoring for a while, and I had error rates of 35-40%. I guess it's a volume problem, but I've got everything turned up. And the IF output volume being at "MAX" on the PSR-800 really eats the batteries.

Try tuning your scanner to any radio station and see if you can record audio from its headphone jack via the Line In socket using any audio recording software. That will at least prove if there is some kind of a problem with the line in.

Regards

Ian

 

[Comint]

. . I had to use the mic-in port (line-in didn't work) and turn the volume way up on the scanner and the mic-in port. . . I guess it's a volume problem, but I've got everything turned up.

If you have to have the volume 'way up', then there is something seriously wrong somewhere. Either a faulty cable, or connection somewhere.

--
Comint

 

[313RADIO]

I setup logging with dmrdecode
I seeing mostly 4 different events

Group Voice Call to Group
Unit to Unit Voice Call

those 2 are easy but these

Capacity Plus Full Link Control LC
Terminator Data Link Control PDU

what exactly is in these transmissions?

also there are some frequencies that seem to be transmitting non-stop data, but there is nothing on slot1 or slot2 what is the point of that?

 

[IanWraith]

Capacity Plus Full Link Control LC
Terminator Data Link Control PDU

what exactly is in these transmissions?

Capacity Plus is a Motorola trunking protocol that is build on top of the DMR standard. A Terminator Data Link Control PDU is a data packet indicating that a data exchange has just ended.

Regards

Ian

 

[dtscho]

Hello All

From what I have read today it appears that Java on the Mac only supports a sampling rate of 44.1 KHz and not the 48 KHz required by the program. So for now it appears the program is only for Windows and Linux PCs sadly.

Regards

Ian

As a follow-up to the issue of using DMRDecode on a Mac, I was able to get the program working on my MacBook Pro by using the iMic USB audio device.

https://store.griffintechnology.com/desktop/imic

Dave

 

[IanWraith]

As a follow-up to the issue of using DMRDecode on a Mac, I was able to get the program working on my MacBook Pro by using the iMic USB audio device.

Thanks Dave its good to hear it works on another platform.

Regards

Ian

 

[loumaag]

As a follow-up to the issue of using DMRDecode on a Mac, I was able to get the program working on my MacBook Pro by using the iMic USB audio device.

https://store.griffintechnology.com/desktop/imic

Dave

and

Thanks Dave its good to hear it works on another platform.

Regards

Ian

Actually, since the platform is the same, just the input method is different this brings up the possibility of using this device for multiple instances of the program running if there is a way of running more than one iMic at a time.

Great info in any case (says the guy with a MacBookPro.)

 

[dtscho]

As a follow-up to the issue of using DMRDecode on a Mac, I was able to get the program working on my MacBook Pro by using the iMic USB audio device.

https://store.griffintechnology.com/desktop/imic

Dave

As I said in this message, I was able to get DMRDecode working on the Mac with the iMic. But I was still using the mono cable with the PSR-800, and having to turn the volume way up (and not getting much in the way of decode). Today, my stereo patch cable arrived from Monoprice, and the results are fantastic. I'm getting much more information, I don't have to turn the volume up, I can use the line-in instead of mic, etc.

I guess the PSR-800's stereo headphone output needs a stereo cord.

Dave

 

[IanWraith]

I guess the PSR-800's stereo headphone output needs a stereo cord.
Dave

That's good news. I have no idea why a stereo cable is needed there must be something unusual about this scanner but now other PSR-800 owners will know what cable is needed.

Thanks again

Regards

Ian

 

[Forts]

Had this entry in one of my logs today:

Service Options : Non-emergency/OVCM Call/No priority

What's an OVCM Call???

 

[IanWraith]

What's an OVCM Call???

I haven't come across one these before. According to the ETSI spec it stands for ..

Open voice channel mode service

It appears to allow certain radios to listen in or take part in calls which aren't addressed to them. Not sure I 100% understand it. Can anyone explain it ?

Regards

Ian

 

[Forts]

The system I'm logging uses Privacy on their groups... could this be some sort of patch setup where the Privacy is disabled to they can connect to other agencies? (Although I would assume for this scenario you would just program in an InterOP channel into the radio and not enable Privacy... but who knows).