Android modem and tracking app

[Matthew Brejza]

Hey all, now available in the android play store is a new android app to add to the recent influx, under the name of 'HAB Modem and Tracker'

As you might have guessed from the name, unlike the other apps, this one has a built in RTTY decoder, as well as being able to grab data from habitat. The app also uses OSM offline mapping, so no internet connection is required. Also part of the app is chase car uploading and graphing.

Some screenshots: http://imgur.com/a/z2VHc

A few points to get started (I don't feel a complete user guide is really necessary):

 - Maps can be downloaded from http://download.mapsforge.org/maps/ (and are required)

 - To change your callsign look in the settings (used for chase car and uploader)

 - To get audio in to your device, a splitter cable is needed. The audio jack on phones/tablets is usually a combined headphone/mic port, and so will need a special cable, which seem to hard to get hold of. However, referring to http://pinoutsguide.com/HeadsetsHeadphones/samsung_moment_pinout.shtml , making a cable from parts from maplin should be easy enough.

 - The echo button on the decoder feeds audio in through to the speakers, however the detection of internal mic or external input does not work too well, so turning this on with no audio input results in a slightly horrific sound.

 - I only have a tablet so this has been tested a lot less on phones. The audio (and so decoder) is known not to work on at least one phone.

The decoder (still very much in beta) supports:

 - 50/300 baud data

 - 7/8 data bits, integer number of stops

 - It is quite sensitive to timing errors, which the reason why it may not work well with some payloads

 - 16bit CCITT checksum

 - Shifts > ~300Hz or so

Planned:

 - Option to use flight data rather than all testing data that might be in the data fetch period

 - Caching payload docs for offline use (this will allow for a greater range of GPS formats. As it has to be able to work offline and so without a payload doc, only non-ambiguous formats will be displayed on the map)

 - Predicted landing point

 - Lots of other bits and pieces

(Potential) FAQs:

 # Can I use more than one map file at once

      - Due to the limitations of the mapping library only one map file at once is supported. You can try to generate your own .map file from OSM data based on instructions here: https://code.google.com/p/mapsforge/wiki/GettingStartedMapWriter (however this is not straight forward)

 # Why is android >= 3 only supported, will 2.x become supported?

      - No, I wasnt planning on it, chances are older devices would have a hard time running it anyway

 # Will directions to the payload be added?

      - When added to the mapping library, yes.

# Can it be translated to ________ ?

      - If someone translates https://github.com/mattbrejza/rtty_modem/blob/master/habmodem/res/values/strings.xml into your language

[Matthew Brejza]

There is now an update in the marketplace for the app which mostly fixes decoder related bugs and crashes on some devices. (I have just uploaded it so it will take a couple of hours to become available)

I have also added a short guide on how to make up a cable on the wiki: http://ukhas.org.uk/projects:hab_modem

Matt

[NickB]

Also had the problem of it crashing on the second decode.

Will try the update. Thanks for the guide!

Op zaterdag 23 februari 2013 21:32:09 UTC+1 schreef Matthew Brejza het volgende:

[Matthew Brejza]

I have added couple more features which should be of help:

- Predictions are now downloaded and displayed on the map for live flights (uses the same data as spacenear)

- The decoder's bit synchroniser has been improved and should work for almost all payloads now. The performance matches fldigi after testing on today's flight

- When the app is in the foreground the screen will dim after a while but will not turn off or lock. This can be disabled in the options

Hopefully this will be of use to someone with the flurry of flights coming up.

Matt 

On 17 February 2013 01:45, Matthew Brejza <mbr...@gmail.com> wrote:

[mclane]

Hi Matt,

I am following your development since some time; however, I never succeeded to get a decode.

My setup is as follows:

Yaesu VR500 receiver -> audio cable -> Google Galaxy Nexus (Samsung)

On my PC running dl-fldigi I get a clear decode with no errors.

On my phone using your app, I see a nice waterfall with the two tones in the middle and the decoder nicely synchronizing on them. I have manually selected the baud rate (50) and the decoder indicates "tracking signal"; however the text appearing on the bottom is simply garbage. The signal is 7N2; however the fields "DATA" and "STOPPS" do not indicate anything (I assume, due to the fact that the decoding is not successfull). On the map page, I have selected my payload (PYSY) and data from habitat seems to be correctly loaded.

Any hint what to do?

Regards,

Uli (ala mclane)

[Kev Walton]

Hi All

Apologies for resurrecting a very old thread, but I find Matt's Android HAB Tracker and Modem App very useful for decoding RTTY on the move.

However on my current handset the Echo function no longer works - it doesn't play back audio through the phones speaker.

The code used is:

public void enableEcho()

{

if (isRecording){

AudioManager manager = (AudioManager)getSystemService(Context.AUDIO_SERVICE);

    manager.setMode(AudioManager.MODE_IN_CALL);

    manager.setSpeakerphoneOn(true);

}

    enableEcho = true;

}

Does anyone have any expertise in how that would need to be changed / debugged and how to build a new APK?

Thanks very much

Kevin

[Kev Walton]

Hi All

I have been working to port Matthew Brejza's Android HAB Tracker and Modem code to Android Studio so I could fix a few things and produce a new APK.  I find the app very useful to do RTTY decoding on the move.

I have now achieved that and there is an APK here:

https://github.com/KevWal/HAB-Tracker/tree/master/habmodem/apk-release

With the following changes

• Includes untested 100 and 150 baud functionality (written by Matt but not released)
  
• Increase the vertical size of the waterfall and message box components on the screen
• Add a waterfall colour gradient scale parameter to advanced options - allows the full colour gradient to be used
• Increase the speed of the waterfall by reducing the default buffer size to 1,500 (was 3,000)
• Fix the Echo button functionality on my Galaxy S10 (doesn't seem to work on some other devices)
• Fix the Strings in the Payload data on the map page

I hope to carry on making improvements, bringing it up to a modern Android SDK and solving issues. 

Matt's original announcement for reference:

A few points to get started (I don't feel a complete user guide is really necessary):

 - Maps can be downloaded from http://download.mapsforge.org/maps/ (and are required)

 - To change your callsign look in the settings (used for chase car and uploader)

 - To get audio in to your device, a splitter cable is needed. The audio jack on phones/tablets is usually a combined headphone/mic port, and so will need a special cable, which seem to hard to get hold of. However, referring to http://pinoutsguide.com/HeadsetsHeadphones/samsung_moment_pinout.shtml , making a cable from parts from maplin should be easy enough.

 - The echo button on the decoder feeds audio in through to the speakers, however the detection of internal mic or external input does not work too well, so turning this on with no audio input results in a slightly horrific sound.

[David Akerman]

Excellent, and I have a feature request :).

Add an option to emit telemetry sentences on a UDP port, then I can have it feed telemetry to my chase app.

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[Kevin Walton]

I can give it a go Dave! Can you point me at the code that will receive those sentences and any examples of other apps that transmit them?

Thanks
Kev

--
Sent from my Android device. Please excuse my brevity.

[David Akerman]

It's just UKHAS sentences over UDP, so if you do some basic sanity checking - which I imagine the code is doing anyway before it uploads to habhub - to know that you have a UKHAS sentence then send it over UDP.

I can send you a teeny program that listens for UDP packets to a specified port via any LAN interface.  If that does your UKHAS sentences then it's working.

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