Pocket25: A Digital Voice Decoder for Android

[noamlivne]

Please test this P25 Phase II build and someone let me know if it's any better:

app-release.apk

drive.google.com

I have samples but they don't playback the same way the original does.

Sent you an email with a video and bug log. Great improvement!
P25 PII sounds much much better, though sometimes it stutters. Conventional unencrypted DMR sound fine for me.
Thank you very much for your efforts.

 

[imonitorit]

I'm getting better audio and some perfect copy. I live 2 miles from one of the towers. The CT statewide (CLMRN) system is simulcast so I've been playing with gain settings to limit that issue which I think causes the audio to get distorted. Great work!!

 

[rgchristy]

I'm only able to successfully monitor one P25P1 system near me. Anything else causes the app to close or hang up.

Please check your PM for Logcat logs and screenshots.

Thanks.

 

[AD8NT]

I'm only able to successfully monitor one P25P1 system near me. Anything else causes the app to close or hang up.

Please check your PM for Logcat logs and screenshots.

Thanks.

Thank you for the details information I'll look into this
Further, I've updated RTL_TCP_ECHO for those looking to provide me with samples

Release v1.0.0 - DMR and P25 Phase 2 Support · SarahRoseLives/rtl_tcp_echo

What's New Fixed recording/playback for DMR, P25 Phase 2, and other TDMA-based protocols Added --samplerate flag for accurate playback timing Proper rtl_tcp header handling (stripped from recordin...

github.com

 

[StoliRaz]

I use an Anker usb hub with an RTL-SDR occasionally.. Just make sure it has PD (power delivery) and it should charge your phone while using the SDR. Mine is similar to this, never had an issue.

https://a.co/d/7G90pzq

Something I failed to mention- you probably also want to pay attention to how close the USB-A ports are spaced together when buying one of these. While the Anker one has worked for me, that's because I only use 1 RTL-SDR on my phone. It would not fit a pair of RTL-SDR dongles, they're too wide to fit side by side. I would assume with Pocket-25 you would need 2 dongles if you were going to monitor trunking systems, one for control channel and the other for voice channels? So you'd need 2 ports spaced out enough to fit 2 RTL-SDRs and the USB-C PD unobstructed.

This cheaper UGreen one has 3 USB-A ports and the PD USB-C. It looks like it would fit everything, so I might pick one up myself-

Amazon.com

 

[AD8NT]

Something I failed to mention- you probably also want to pay attention to how close the USB-A ports are spaced together when buying one of these. While the Anker one has worked for me, that's because I only use 1 RTL-SDR on my phone. It would not fit a pair of RTL-SDR dongles, they're too wide to fit side by side. I would assume with Pocket-25 you would need 2 dongles if you were going to monitor trunking systems, one for control channel and the other for voice channels? So you'd need 2 ports spaced out enough to fit 2 RTL-SDRs and the USB-C PD unobstructed.

This cheaper UGreen one has 3 USB-A ports and the PD USB-C. It looks like it would fit everything, so I might pick one up myself-

Amazon.com

Only one is needed for trunked systems.
It leaves the control channel and monitors voice when active then hops back to the control channel.

 

[StoliRaz]

Only one is needed for trunked systems.
It leaves the control channel and monitors voice when active then hops back to the control channel.

Cool, good to know. Do you have an idea of when it'll be on Google Play or is that still too far off in the future? I haven't tried it but it looks good

 

[I_Am_Infinite]

I haven't got a chance to download and try as I don't got an SDR so I'm not sure if this can be added or already exist on the app, but signal strength meter, like scanners etc have

 

[AD8NT]

I haven't got a chance to download and try as I don't got an SDR so I'm not sure if this can be added or already exist on the app, but signal strength meter, like scanners etc have

I'll take a look at what all DSD exposes and see what I can hook into.

Side note: Video overview of the app can be found here with some in-action shots on a Phase 1 P25 system.

 

[Dan_C]

Does the software need any drivers to work or is it USB straight out of the box?

 

[AD8NT]

Does the software need any drivers to work or is it USB straight out of the box?

Your phone must support USB OTG (host mode) and you'll need an OTG cable to connect the RTL-SDR (unless using rtl_tcp)
There is no special driver needed, the app communicates natively with the RTL-SDR

 

[AD8NT]

I've added a web-based programmer for those who don't have premium radio reference accounts.
This will allow you to manually create systems and import them into Pocket25.

Eventually I hope to support csv importing and exporting as well.
You may download a new copy from Pocket25 - Digital Voice Scanner for Android using the account you originally created to get the newest release.

 

[I_Am_Infinite]

I'll take a look at what all DSD exposes and see what I can hook into.

Side note: Video overview of the app can be found here with some in-action shots on a Phase 1 P25 system.

Your doing a really good job with this. A signal strength indicator (bars) wud absolutely be amazing but I've never seen any software for decoding SDR signal with it so I'm not even sure it's possible. But it would be really cool and a unique addition if possible. Thanks for looking into.

 

[Mobby1-Kenobby]

Hi, AD8NT

I downloaded your Pocket-25 apk and installed it on my Eonon car stereo.

EONON GMX6S2 Specifications
Operating system, Android 13
Processor, Qualcomm QCM6225-AD
CPU Architecture, 8-core (4×A73 at 2.8GHz + 4×A53 at 1.9GHz)
RAM, 6 GB
Storage, 64GB
Display 8" QLED Touchscreen
Resolution 1280*720
Operating voltage DC12V
Android Auto Wired & Wireless
Wi-Fi Support 2.4G/5G & Wi-Fi 6 ready
Built-in 4G module
USB inputs, 3

I have included a few pictures.

The system being decoded is: Provincial Public Safety Telecommunications Network Trunking System, Provincewide, Saskatchewan

Unfortunately no channel grants are seen and no unencrypted P25 voice call audio is heard.

Logging is showing a great many error messages.

It appears the program decodes P25-P1 'implicit' messaging but it does not decode P25-P1 'explicit' messaging.

https://www.qsl.net/kb9mwr/projects/dv/apco25/P25ControlChannelFunctions.pdf

You are doing some very impressive work. Keep at it.

Cheers to you!

 

[AD8NT]

Hi, AD8NT

I downloaded your Pocket-25 apk and installed it on my Eonon car stereo.

EONON GMX6S2 Specifications
Operating system, Android 13
Processor, Qualcomm QCM6225-AD
CPU Architecture, 8-core (4×A73 at 2.8GHz + 4×A53 at 1.9GHz)
RAM, 6 GB
Storage, 64GB
Display 8" QLED Touchscreen
Resolution 1280*720
Operating voltage DC12V
Android Auto Wired & Wireless
Wi-Fi Support 2.4G/5G & Wi-Fi 6 ready
Built-in 4G module
USB inputs, 3

I have included a few pictures.

The system being decoded is: Provincial Public Safety Telecommunications Network Trunking System, Provincewide, Saskatchewan

Unfortunately no channel grants are seen and no unencrypted P25 voice call audio is heard.

Logging is showing a great many error messages.

It appears the program decodes P25-P1 'implicit' messaging but it does not decode P25-P1 'explicit' messaging.

https://www.qsl.net/kb9mwr/projects/dv/apco25/P25ControlChannelFunctions.pdf

You are doing some very impressive work. Keep at it.

Cheers to you!

Thank you sooooo much for sharing this!
It's one of the use cases I've been dying to see from the get go!
I'll review the information provided in the PDF, right now it's based on DSD-Neo so if it doesn't do it I'll need to look at the core of the application and see how/why it handles 'explicit' messages the way it does.

 

[rgchristy]

Is the link to the apk in post #32 the same apk that is listed in my downloads?

When I click on the link, it takes me to the purchase screen. When I log in and click on my downloads, it shows this:



I want to try to start over by uninstalling and reinstalling, but I want to make sure that I have the latest version. I'm not sure that January 13th is the latest, since your message #32 is from Friday, 1/16.

Thanks

 

[AD8NT]

Is the link to the apk in post #32 the same apk that is listed in my downloads?

When I click on the link, it takes me to the purchase screen. When I log in and click on my downloads, it shows this:

View attachment 195580

I want to try to start over by uninstalling and reinstalling, but I want to make sure that I have the latest version. I'm not sure that January 13th is the latest, since your message #32 is from Friday, 1/16.

Thanks

That's just the date you originally downloaded.
If you download it today you'll get the latest copy of the APK.
I will likely put together a better system for grabbing updates, that actually shows when it was last updated.

 

[rgchristy]

Thank you.

I'm starting over to make sure that there is nothing that I'm doing wrong on my end.

I'm running a Samsung A36 5G with Android 16 in developer mode

I following your video above step-by-step

Right off the bat, when I search for "otg" or "otg storage", the message is nothing found

When I search for "settings", there are a bunch of options, but nothing like your screen at the beginning of the video

When I plug in my RTL-SDR v3, I get the following message:



That's as far as I've gotten.

 

[AD8NT]

Thank you.

I'm starting over to make sure that there is nothing that I'm doing wrong on my end.

I'm running a Samsung A36 5G with Android 16 in developer mode

I following your video above step-by-step

Right off the bat, when I search for "otg" or "otg storage", the message is nothing found

When I search for "settings", there are a bunch of options, but nothing like your screen at the beginning of the video

When I plug in my RTL-SDR v3, I get the following message:

View attachment 195599

That's as far as I've gotten.

What happens if you click okay, anything?
My phone requires turning OTG on, but yours might be on by default? I'm not sure.

 

[rgchristy]

Default USB configuration under Developer options is set to "Transferring Files"