Simple Android App for P25RX

goldmyne99

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Jul 23, 2018
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I have been experimenting with Android and the P25RX using an OTG usb cable for displaying data. I am not a programmer. Just playing around in the radio hobby.

This is a 30 sec mp4 video file of the app I built running on an old 2013 Nexus 7 tablet (2 gig ram and Andriod 5.1.1). P25 Phase 1 and Phase 2 systems near me.

Mp4

The app has a short TG history pop up window, a direct frequency enter window, and a TG follow button. The Nexus 7 powers the P25RX. Sound remains line out/bluetooth from the P25RX.

If any fellow experimenters are interested, I will gladly share the completed 3 meg apk file with you for free. I'm good at yahoo email.

To be clear, I am NOT selling anything. I built it with "MIT Ap Inventor 2" and just like sharing ideas as part of the hobby. It just parses the text seen in the BTConfig console. As such, future releases may cause the app to fail and need updating. But for now...it works.

Please understand, I can not support troubleshooting or feature requests. It may NOT work for you.

The Android device must support OTG serial with an OTG cable. The apk file will need to be sideloaded on your device for installing. Too many flavors of Android for me to provide any knowledge on how to do things on your specific device.

It works well on my 3 Android devices. Two old Nexus 7's and a newer ONN 10.1 tablet with Android 10. My 2012 Nexus 7 (1 gig ram and Andriod 4) does not like it when opening the TG history pop up. Everything else works fine on that unit.

Just having fun with the P25RX, I hope you are too. It is a great device!
 

btt

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I have been experimenting with Android and the P25RX using an OTG usb cable for displaying data. I am not a programmer. Just playing around in the radio hobby.

This is a 30 sec mp4 video file of the app I built running on an old 2013 Nexus 7 tablet (2 gig ram and Andriod 5.1.1). P25 Phase 1 and Phase 2 systems near me.

Mp4

The app has a short TG history pop up window, a direct frequency enter window, and a TG follow button. The Nexus 7 powers the P25RX. Sound remains line out/bluetooth from the P25RX.

If any fellow experimenters are interested, I will gladly share the completed 3 meg apk file with you for free. I'm good at yahoo email.

To be clear, I am NOT selling anything. I built it with "MIT Ap Inventor 2" and just like sharing ideas as part of the hobby. It just parses the text seen in the BTConfig console. As such, future releases may cause the app to fail and need updating. But for now...it works.

Please understand, I can not support troubleshooting or feature requests. It may NOT work for you.

The Android device must support OTG serial with an OTG cable. The apk file will need to be sideloaded on your device for installing. Too many flavors of Android for me to provide any knowledge on how to do things on your specific device.

It works well on my 3 Android devices. Two old Nexus 7's and a newer ONN 10.1 tablet with Android 10. My 2012 Nexus 7 (1 gig ram and Andriod 4) does not like it when opening the TG history pop up. Everything else works fine on that unit.

Just having fun with the P25RX, I hope you are too. It is a great device!
Great work! Can this app generate sound from PCM samples? You can see how to decode the audio over the virtual serial port here:


Look at void process_usb_rx( uint8_t c ), case 4: The voice information is only output if 'en_voice_send 1'. The BTConfig software sends this command to enable 8 kHz binary voice output. The case 4 in process_usb_rx() shows how this binary data is encoded.

The first 4 bytes for a voice frame are this:
#define VOICE8K_MAGIC 0xb25f9c71

Then followed by 320 bytes or 160, 16-bit signed mono audio words at an 8 kHz rate.

There is also an audio flush command. Shown in case 3:, c==0x31

-edit: I just read you post again. I guess there really is no reason for the phone to produce the audio. The P25RX can do this direct or via Bluetooth. Again, great work! I look forward to seeing more. Hopefully, examining the above file from the display project will give you some more ideas.
 
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goldmyne99

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Jul 23, 2018
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Thanks for the kind words!
I will be looking at the display project for possible ideas. I am limited by what the MIT App Inventer modules can support and my limited programming skills. I know it does support audio streaming. My goal was getting display and some control buttons worked out. Just living and learning. A big thanks to you for bringing the P25RX to life!
 
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ka3jjz

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If you put this in a dropbox or on Google Drive, it can be linked in our new wiki...Mike
 

goldmyne99

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Jul 23, 2018
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If you put this in a dropbox or on Google Drive, it can be linked in our new wiki...Mike
Thank you for the suggestion.

At this time, I prefer to continue to share the apk with those that contact me (email or direct message here) as noted in my first post. As I am experimenting with my limited programming skills, I am not ready to post an experiment to the world.

The good news is that many have had success with the app on their devices. Only one had an issue that was easy to resolve.

Have fun. Enjoy your P25RX.
 
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phillydjdan

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Can't send you a direct message but I'm interested in the apk. If you can email it to me, it's philly.djdan at gmail, thanks.
 

goldmyne99

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Jul 23, 2018
Messages
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Just an update on my Android app experiment. Many have found it to be useful and have provided great feedback to improve it. Thank you!

I am continuing to make improvements to my Android apk. An Apple version of my app is not possible for me to create.

However, I wanted to experiment to see what is possible.

I put together a "proof of concept" WI-FI access point web server connected to the P25RX usb. This allows for displaying the P25RX info on a device with WI-FI and a web browser.

This "stand alone" access point web server uses an ESP8266 WI-FI module. No internet connection needed.

Three wired connections:
ESP8266 wifi module -> Arduino/USB host module -> P25RX usb.

The Wi-Fi connection:
A phone/tablet/laptop connects via Wi-Fi to the ESP8266 access point.

A lot of trial and error with Arduino code, html code, etc.

Here is the P25RX real time data displayed via WI-FI on my Apple SE web browser. (display info only...audio remains line out or Bluetooth).
p25rx_wifi.png



I am not a programmer. This is very much a learning experiment as a hobby.

I would encourage others to have fun and experiment. You never know...your ideas may just surprise you!
 
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Thank you for the suggestion.

At this time, I prefer to continue to share the apk with those that contact me (email or direct message here) as noted in my first post. As I am experimenting with my limited programming skills, I am not ready to post an experiment to the world.

The good news is that many have had success with the app on their devices. Only one had an issue that was easy to resolve.

Have fun. Enjoy your P25RX.
RR is letting me Direct message, can you email me at jsteinbrech @ gmail.com
thank you
 

hkrharry

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goldmyne99
I can report that your program works on my Lenovo Tablet, thanks for the App, looking forward to updates as you improve features.
All the buttons provided seem to play just fine.

I am going to try and install it on my Sonim XP8800 phone and see what happens.

HH
 
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W4KRR

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For those who have got this working, how are you getting audio? Bluetooth from the P25RX device to earbuds, or some other method?
 
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