OpenCpn Install on Android Tablets Easier Now.

[houlejm]

Marius

I downloaded NMEA Test.

It works well on my Samsung Galaxy Tab 2 10.1, Android 4.1.1

Jean-Marie

[mrm]

Roel, Jean-Marie, thank you very much for your reports.

Marius

[alex2035]

I would like to thank Armido, Sailias, et al , for their effort on this excercise. Having OCPN on Android tablet is a very good idea that I would want to see realized completely.
I might get one and try this to add another voice to the project.

alex

[armido]

Marius,

My absence from this thread is explained by the fact I have not had access to the internet since leaving Trinidad on Jan, 10. I am only able to send this now because an engine cooling problem has interrupted my voyage and brought me to a marina with wireless access.

There is an apk available from Google Play called GpsTest. Why would it be able to display my built-in gps information if it weren't able to read nmea data in a similar fashion to your nmea test because my ROM is buggy? I tried your test by starting it before and after the built in gps was activated. Same result. No nmea data output displayed. What is different between your test an GpsTest?

armido

[armido]

I just received an update to my recommended linux Installer, Linux Deploy. Arch Linux was added as a distribution choice in the last update. I've never used Arch Linux, so can't recommend for or against. But what's really great about today's update is that Fedora - my flavour of choice ever since Red Hat forked to provide supported as well as free (unsupported) versions - is now offered by Linux Deploy as an option. Fedora 17, the same version running on my laptop - is now available for my Xoom! Nows my chance to do a full wipe, install a new Jellybean ROM (provided most bugs have been resolved), install Fedora 17, OpenCPN and zyGrib all over again. Can almost do it with my eyes closed now...

armido

[mrm]

Originally Posted by armido

Marius,
[...]
There is an apk available from Google Play called GpsTest. Why would it be able to display my built-in gps information if it weren't able to read nmea data in a similar fashion to your nmea test because my ROM is buggy? I tried your test by starting it before and after the built in gps was activated. Same result. No nmea data output displayed. What is different between your test an GpsTest?

armido

armido,

without access to the source code I can only guess that GpsTest app uses GpsStatusListener interface to GPS data. However, this interface does not give access to NMEA data.

Marius

[armido]

mrm,

I'll be out of the loop again for the next several days - sailing northward resumes tomorrow.

What can you recommend for those who's device does not play well with your nmea test?

Using a gps with my tablet install of OpenCPN isn't important to me, but if it were - knowing I am using a custom ROM - what should I do? Is it likely an original Motorola ROM will work any better? Would this be likely no matter which tablet I own, provided it runs an oem android ROM?

I am asking because this will affect many a tablet owner's ability to use a gps with OpenCPN running in a chrooted linux environment. Am I getting ahead too early and too far on this? Since I and most others following this thread are presumed to have little knowledge of how android apks are created, we are clueless as to how what you are doing relates to our ability to eventually use a gps in OpenCPN on our tabs.

Thanks,
armido

[mrm]

Originally Posted by armido

mrm,
[...]
Is it likely an original Motorola ROM will work any better? Would this be likely no matter which tablet I own, provided it runs an oem android ROM?
[...]
I am asking because this will affect many a tablet owner's ability to use a gps with OpenCPN running in a chrooted linux environment. Am I getting ahead too early and too far on this?

armido,

I am researching this and information is scarce, scattered in bug reports and such. For now I conclude, that oem ROMs have less problems in this area (test results I received so far suggest no problems on oem ROMs, but the sample is too small to be statistically valid).

At the moment I think that custom ROM may be a bit too far ahead, while it is likely you would have success with oem ROM.

In fact, if you have time and could temporarily go back to oem ROM on your device and test this setup, your results would be very valuable.

Marius

[hwecken]

Originally Posted by mrm

Here is the app: http://infinity.eti.pg.gda.pl/tmp/NMEATest.apk

At the moment the only functionality is as follows:
- if device's GPS is switched off, application will patiently wait;
- if the GPS is on, first 200 NMEA sentences received will be displayed, then the app will stop;
- minimum Android version supported is 2.3.3, API 10.

All testers: please report if it works for you as described or not and include the device make/model and Android version in your feedback.
TIA

Marius

Hello Marius
your APP works as described on my ASUS Transformer Pad TF700T with Android 4.1.1
Hartmut

[mrm]

Hartmut, thank you for your report, appreciated :-)

Marius

[armido]

maurius,

Thanks for your reply. I've backed up the original ROM. Finding it among the several backups I've got may be a challenge though. Maybe Motorola has a download. It would be great if another Xoom owner could step up to bat here though.

aarmido

[armido]

Marius,

May I suggest you start a thread at xda inviting users of android devices to run your test? A quick search there reveals lots of discussion about nmea issues on android tablets - all over my head. Regarding the Xoom, there is an issue with Gingerbread 3.0.1 regarding nmea: http://osdir.com/ml/Android-Develope...3/msg04802.htm l think I was using Gingerbread 3.2 before going custom.

armido

[armido]

Marius,

The "htm" in the provided link should be "html". Can't copy & paste into my posts here using the Xoom - so more room for typos.

armido

[armido]

Marius,

Can you please explain how the apk called "GpsTest" is able to display latitude, longitude, time, heading, speed, and altitude without receiving nmea data from my built in gps? It is a mystery to me. And, if it is providing this information in some other way - without getting too technical, can you explain? Is this apk's dev onto something requiring only a small tweak to make the connection we seek?

armido

[mrm]

Originally Posted by armido

Marius,

Can you please explain how the apk called "GpsTest" is able to display latitude, longitude, time, heading, speed, and altitude without receiving nmea data from my built in gps? It is a mystery to me. And, if it is providing this information in some other way - without getting too technical, can you explain? Is this apk's dev onto something requiring only a small tweak to make the connection we seek?

armido

armido, I'll try to explain what I *think* "GpsTest" app is doing. Without looking at the source code I can only guess, but having looked at Android API I hope it is a somewhat educated guess..

Let's start with the very basics. A smartphone is essentially a computer. A computer consists of hardware, operating system and applications - think of them as layers, building on top of another, with hardware at the bottom and user applications at the top. For most of the time users interact with applications, without giving a second thought to the underlying layers of software and hardware, expecting them to 'just work'. That is OK, in fact good hardware and good OS'es rarely require users' attention.

Programmers, on the other hand, have a different perspective. In the process of writing an application, they have to consider *how* to interact with various hardware and system services present in a computer. Historically there was an evolution. First programs interacted directly with hardware. This was, of course, extremely counterproductive. Every programmer who wanted to, say, print a character on a printer (or rather punch a tape) had to figure how to do that themselves and write a piece of code to do that. Thus, a concept of an Operating System was born.
Operating System is in essence a housekeeper, offering standard ways to interact with services and resources present in a computer. This way an application program can simply use a standard interface to tell the OS 'here is a line of text, please print it' instead of doing it on its own. A collection of such interfaces is called an API (Application Programmers Interface).

Alright, this was a bit lengthy prelude. Anyway, remember the API concept.

Android OS is no different, it offers various APIs to access different areas of the device's hardware and other services including... yes, you guessed it, including the GPS data.

In fact, Android offers *two* different APIs for GPS access. They are somewhat complementary.

One of them is sort of dedicated to NMEA stream.

The other offers access to 'cooked' data (like speed, heading, etc.) and information on satellites' elevations, signal strength, etc.. All this *without* showing any NMEA to the application.

My guess is, that "GpsTest" presents information which it obtains by means of the second API, the one without NMEA access. In fact its functionality mirrors the API functionality pretty close.

Hope it was clear enough.

My apologies to computer scientists and geeks reading this.

Marius