Dive computer logs

[araviele]

Hi, I'm a rec diver writing a simple android dive log app. I've built the dive log app and it works great. Much better UI than what I've seen and what I need. I've used it for some diving in Cozumel late last year. I am now trying to integrate dive computer downloads taking advantage of recent android USB api functions and that works great. I can get my dive computer data! I need help parsing the dive log data. I have an Oceanic VT4.1 that I've been using and I have the dive log and can see where 84 dives are delimited in the log data but I can't decifer the data. Tried the company to help with log structure but no luck. Is there anyone on the Board who can help?

Btw, writing this in Java, not C. Looked at Subsurface and other existing dive apps. Liked Subsurface but the app was a over the top for my needs and the UI was not intuitive in some instances but the download function worked well. Tried to use lib divecomputer (download library) but I'm a newbie (read hobby for a retired guy) to this stuff and didn't know how to use it for android.

So again, any guidance would be great and appreciated.

 

[txgoose]

Unless you're just looking to create your own app, which I get, I suspect that Subsurface would be open to a more rec centric UI option. They appear at least quasi open source. I also think that the UI could use some work, but I am also not contributing code so I like what I get. If you go contribute there, then I win.

 

[dmaziuk]

libdivecomputer tarball has several .c/.h files for oceanic, that would be where I'd look.

 

[araviele]

Unless you're just looking to create your own app, which I get, I suspect that Subsurface would be open to a more rec centric UI option. They appear at least quasi open source. I also think that the UI could use some work, but I am also not contributing code so I like what I get. If you go contribute there, then I win.

That's and an approach to the problem I have not considered. Thanks.

It is a rec diver app. Graphic. Easy to use. Maybe the Subsurface team might be interested. I'll ask while I try to untangle the logs.

 

[araviele]

libdivecomputer tarball has several .c/.h files for oceanic, that would be where I'd look.

Yea. Unfortunately I think that's the route I'll need to go if someone doesn't have the magic log key for an Oceanic VT 4.1 readily available and willing to share.

Thanks for the reference.

 

[dmaziuk]

yep, and that someone is libdivecomputer. Subsurface has their sources in github too, you can view the files in the browser instead of downloading the whole tarball...
Subsurface-divelog/libdc

 

[elmo]

Assuming you are only interested in supporting your dive computer... Searching for VT4 in the libdivecomputer file Subsurface-divelog/libdc tells you that it belongs to the Oceanic Atom2 family. Even if you are not a C programmer the following files are likely to be useful
Subsurface-divelog/libdc
Subsurface-divelog/libdc
Subsurface-divelog/libdc
Subsurface-divelog/libdc
Be sure to read and understand the licence stuff at the top of each file. This is especially important if you end up sharing your app.

Unless you're just looking to create your own app, which I get, I suspect that Subsurface would be open to a more rec centric UI option. They appear at least quasi open source. I also think that the UI could use some work, but I am also not contributing code so I like what I get. If you go contribute there, then I win.

What is "quasi" open source? It is licensed under open source licences, Subsurface code is free to download, the apps are free to distribute, the development discussions are accessible and developers are pretty responsive.

 

[txgoose]

What is "quasi" open source? It is licensed under open source licences, Subsurface code is free to download, the apps are free to distribute, the development discussions are accessible and developers are pretty responsive.

Wasn't trying to make a legal case. Notice I said "at least." Simply an outsider not well versed in the legalese of coding licenses encouraging him to look into it. Thank you for the detailed clarification.

 

[dmaziuk]

It's not "open source", it's "free" that's GPL code is not. However, you'd need to ask a lawyer whether reading the GPL'ed source to figure out the file format, and writing your own code to read those files, makes your code "derived work" in the legal sense.

 

[atdotde]

It's not "open source", it's "free" that's GPL code is not. However, you'd need to ask a lawyer whether reading the GPL'ed source to figure out the file format, and writing your own code to read those files, makes your code "derived work" in the legal sense.

I cannot really follow your first sentence. Subsurface is GPL 2.0 (except some parts it uses like EXIF parsing which comes with a different open source license) which is quasi by definition open source. I don’t know your definition of „free“ but sure it is not public domain: if you create derived work and share it (which is encouraged) you have to do it as open source as well, that’s copyleft.
There is no copyright on procedures or algorithms, so you can read open source code to learn how it works and recreate it from scratch. There is only copyright on the implementation. So when you copy and paste code, that’s a derived work.

That said, I believe in general it’s a better idea to share forces rather than the hundredth new program each with its own deficiencies. Thus I would always rate it a better investment of time to improve an existing project (unless it’s broken beyond repair) rather than starting a new one.