Notices

Follows on from my most recent mbarcode thread post.

Yesterday+today I did some more (minutes) of dev work towards my plans for a working bitcoin mbarcode plugin that can read QR codes (commonly used to show bitcoin addresses for payment) and tried to get a dialog appearing to allow you to choose some actions for the address it finds.

Roadmap
The starting plan is to be able to do 3 actions with a scanned address:

1. show address' confirmed balance
2. show address history
3. pay scanned address some btc amount

Balance/History
History and balance being the simplest to start with and will basically just open up a browser to relevant blockchain.info page (or equivalent) for the history or do an API fetch for the current (confirmed) balance from same/similar service.

Payment
This will require more thought, and I'm being selfish for my own requirements for now; no plans to keep a full bitcoin client/daemon on the N900 unless someone can tell me how to do it and keep good battery life and still up to date with the blocks. Other people have hinted via posts that a full client is impractical.
I also have no plans to ever use a webwallet where some third party company knows the private key, so thats a bit limiting too (and if thats what you'd like, you better make it worth my while to work on that, but hold off a bit until I get some kind of basics done, both for your and my sake).

This indicates that some kind of web/other computer service would probably be needed, whether just to track the blockchain or for forwarding transactions (ie. need to choose thin/fatter client style). One thought that springs to mind is copying the Trezor or other hardware wallet schemes (various implementations have been prototyped). Not looked at that yet.

I think there might still be some options within those constraints, if anyone into bitcoin can list any that do that'd be great as I'm not sure I can remember which ones work which ways; I also have some thoughts I need to research to see if they're do-able security-wise for what bitcoin clients need to transact.

Web-wallet support (via some vaguely common API, ideally) may or may not arrive, if people want to make it worth my while then I'll do that after I have the basics done and figured out some UI stuff.

What I do/don't have:
* Recognising and logging the bitcoin address from a QR code using my own python plugin for mbarcode (this bits fairly trivial), copes whether its "bitcoin:" prefix or not.

* I, separately (as a standalone python prog) have a dialog popping up from the command-line intended for choosing/firing the actions, and code ready to call the browser with the right url for the history.
- but in my dialog window, the (getting techy a moment now) gtk.VBox doesn't appear in it after I've .add()'ed it (filled with my HBox'd buttons and label to show the address) - can I do it ok without creating a hildon.window/hildon.program first? Seems like I ought to be able to. Don't know if that also works fine over the top of the existing UI in mbarcode which I think uses Qt for the camera stuff? Actually its some weeks since I checked that part.. There'll likely be a standalone bitcoin app too btw, doing the same stuff but that takes its addresses from a text box (eg. copy-pasted) so you can still do stuff from eg. a btc address on a web page. Having a url plugin handler for bitcoin:xxxxxxxxxxxx addresses might be handy too but that's a way off being thought about yet (considering my current roadmap anyway, though that can change lots).

* Nothing beyond recognising the address works yet
(though the scanned-address's history via opening the browser should be trivial once the dialog UI works, got code to do everything but actually calling the browser for that already).
* The app/plugins will be very configurable, so they can use blockchain, blockexplorer or other service via specifying the url pattern as long as the output is easily parseable. All my apps I write (as an experienced professional python/C++ dev) tend to be pretty configurable and have logging for my and everyone else's needs.

Other Thoughts...
Any ideas for an app name? What about "Bitmaecoin"? BitcoiN900? (I'm not great at picking them..).

Donations will at some point be gratefully received but won't guarantee anything at present, talk to me directly/on here about something if you have greater needs and some patience as I do have a day-job. I'll update this post later if it gets to that point.

Background:
I recently moved to an Android phone but am still carrying my N900 about with me until more stuff is transferred over. I still love the physical keyboard and I still plan to use it for certain tasks where its easier or better to for it to be separated from a device with other account access.

I'm less confident about privacy/security on Android for doing things like bitcoin/other financial/personal/potentially risky tasks at present (little experience yet, and its hard to have everything be open source, though am exploring F-droid app store).

Hence my plan for my N900, for it to become more of an appliance for certain things.

(continued rant...) Most useful apps I see/hear of are written by people I don't know their reputation and can't see the code - thanks to the few that do have github repos but otherwise its a barren wasteland of proprietary apps that might be coded well or terribly/maliciously, its so hard to tell and mostly only ever via negative proof of security when holes/back-doors/spyware/... are discovered by 3rd parties.

So I've probably done about a day and a half's work on it since the first post above, and I seem to have motivation to continue for now; but I also discovered (after using khteditor), Khertan has a bitcoin client for Sailfish/Meego, and wondering if it might be portable to Maemo without too much effort. Its on github so am going to check into that, or see if I can grab some ideas from it.

(link to github source via Khertan's projects page at http://khertan.net/ )

I would be very interested - I got a whiskey at the Pembury Tavern with bitcoin on my N900 - it took me ten minutes to scan the code, manually edit and copy it into my blockchain.info wallet, type in the exact amount manually. It worked but in no way I would love to replicate it.
Will defintely donate, please continue your ideas!

Thanks for the interest and support. I imagined it might be painful. 10 minutes is long enough to validate the transaction in the next block

I haven't forgotten it but some weeks I get more done than others. spent 2 and a bit days equivalent work on it so far but still learning the gui programming side of it somewhat and the GTK objects.

I tried bit purse but didn't get past needing one of the QML libraries it failed to find that is obviously not as backwards compatible to Maemo. It almost looked like it could work though. I'm having more fun with g t k so am following that path for now, whether it's more useful in future for me or not! (probably less so). Once it works well enough I can consider redoing it with better design and learning more portable mobile dev skills...

Any more progress? I'm dying to start playing with and using it.

I got to a point where some individual parts of it were working, but then stopped working on it and haven't done any more work/integration for a month or more.

Have another couple of personal projects I'm working on away from my N900, but I will try to get back to it in the next week or two once I've pushed some other code to github for one of the other things.

This is very cool after a long break from bitcoin app development.
http://talk.maemo.org/showthread.php?t=66756
Does anyone remember back when the N900 was the first mobile device to get a bitcoin app, it was command line only.
(edit)
Wow, reading that thread back when people actually tried to mine coin with a N900!

Well at that time it was sure possile, as the chains were so much shorter. Had I had todays HW available back then there'd be no coins left for anybody else

I had a friend about then who bought a hot video card and mined 300 coin the month before some big player with heavy computing power moved in and grabbed all of the remaining short chains. My friend realized that he didn't have enough power anymore and returned the card before the 30 days were up. He really panned some gold, worth over $30,000 at one point.

How's it going?