Topic: BitcoinSpinner - page 17. (Read 55489 times)

There are Canon printers (and perhaps other brands) that take a bluetooth connection and print directly from your phone. You could take a screen shot of the QR code and print it straight from the phone.

Base58check takes care of the little typos, at least O0Il.

If you have any significant amount of bitcoins in your wallet, be careful which systems your backup goes through. Avoid pulling it through a computer.

The following advice is only for fat wallets. If you have less than, say, 100 bitcoins, you can probably take the small risk that they get stolen. But if you have more, read on.

Printing from your phone directly to a printer without a computer in between would be fairly safe, possibly the best way to do it. But be careful not to use some service that uses any computer or cloud in between. That wouldn't cut it. Direct-printing USB or Bluetooth printers are still a rare breed though. I guess things will get better over time.

Unfortunately you cannot put the phone face-down on a copier. The copier beams too much light at the original, so the phone screen will not be visible on the copy.

Photographing the QR code with a Polaroid camera would do just fine, but those are out of fashion these days. If you still have one, keep it usable for this purpose. Polaroid has a cute Bluetooth printer for smartphones, which would solve the problem very nicely, but that would set you back another $100.

Taking a screenshot and pulling it through your computer is decidedly less safe, but then an Android phone with many programs installed and usually connected to the Internet is also not safe. You could have a bitcoin-stealing Trojan on it, for example, or some remote-controlled spying software.

If all else fails, you can still copy the wallet backup to the clipboard, paste it into a text editor, and write it down on a piece of paper by hand. Just understand that every single typo will completely invalidate your backup. I'm not sure about digit zero vs. upper-case O and lower-case L vs. upper-case i ambivalence, but you could try to use a text editor with a font where each character is unique. Test your backup before you rely on it.

If you have a larger amount of bitcoins on a phone, you probably want a separate phone without an always-on Internet connection and with little or no extra software installed. That would be your little bitcoin safe. An older Android phone, factory-wiped, devoid of unneeded software, and with all Internet connections switched off is ideal. Of course you have to connect it to the Internet to do a transaction, but disconnect it again when you're done.

Yeah. I know how to get the plaintext string. Now I have to enter it into another tool to get the QR code again to print it. I was wondering if there was a shortcut I'd forgotten. Probably not, from the responses.

If you copy the qr code, it goes into the clipboard as the plaintext string. You can then do what you wish with it.

If you have the ZXing barcode scanner, you can paste the text in there and it will turn it into a qr code which can be shared. I have the brother printer app so I printed it out but you could also do all the other standard sharing things (just don't share to Facebook).

Perhaps Jan could add sharing directly in a future release.

You wouldn't want to email it. Think of the consequences of it floating around for everyone to see.

Jan,
I forgot. To print a wallet backup QR on paper I have to actually take a photo of the QR code as displayed on my phone. I can't export the QR image or email it or anything. Right?

o_dima, thanks for the input. As Gizmo states, he made a patch for this, but I didn't apply it yet, so it is all my fault. Right now I am 110% booked with some great stuff that will be demo'ed at the May conference, and I am not likely to release an update until after that.

There is a patch for that!
You may upvote it or suggest improvements if you don't like the result and I can improve on it.

If you are not an Android developer, I could also provide you with a binary but I'm even too lazy to use my own version so it's not being updated and easily available on the market neither. Google has some strange rules about "exporting crypto" that scare me from putting my version on my developer account as I don't want my account to be suspended. (Well, actually writing this, I feel really like a sissi. Maybe I put it online soon but then again I don't want to step on other people's feet and would have to change the name but still honor Jan and other people's work sufficiently to not be the bad guy … and how about using Jan's server? Well … you know )

Hi Jan,
One uncomfortable thing is that BitcoinSpinner shows that your funds is beeing sending until 1st confirmation comes but most servises shows your payment complete after 6 confirmations. So it might stress new users - money went out and only  2 hours later appears at their destination.
The various solutions could be:
- make a number of confirmations 1-6 as parameter in settings,
- show the number of confirmations for each line in the transaction history,
- make a line in the transaction history as an active clickable link to transaction-ID page at blockchain.info.

Right, I haven't added key import yet. The good news is that it is very easy to send bitcoins from one address to another ;-)

I found this app last week.  I think there might be a bug when I press the back button then launch the app again -- it sends me to a blank screen with the app's name as the title.  I hit back, and it launches normally.

If I can just figure out how to get the address from Andreas's app onto this one, I'll be very happy.

Edit:  As far as I can see, that bug I was talking about was fixed.  It looks like I can't import the private key from another address made with Bitcoin Wallet for Android to BitcoinSpinner.  Ah well.

New version out 0.8.2b:
-Using MtGox's new ticker located on data.mtgox.com. The old one is being deprecated.
-Updating Russian translation according to O.Dima V's changes

Upgrade from Google Play or alternatively you can do a direct download at: https://code.google.com/p/bitcoinspinner/downloads/list

Enjoy

Thanks for this info.

It is going to be interesting to see bloom-filters integrated with wallets. I believe that we need all the diversity we can get, so BitcoinSpinner is not going the bloom-filter path. 
I am working full time for Bitcoincard now, and since the company regards the backend system as a strategic asset they are evaluating currently evaluating the benefits of open sourcing it. I can hopefully tell more about this after the conference.

With bloom filters on the horizon or kind of available already, will BitcoinSpinner continue to use its custom server or will this allow to turn it decentralized and independent from one particular server?

Edit: All the effort that went into the server rewrite and negotiations with some BTC companies sounds like the answer is no.

(I didn't follow this thread yet. Don't know why )

Regarding the blockchain fork currently in progress, BitcoinSpinner is on the 0.7 (winning) chain.

Yeah, I thought I heard you changed some stuff in order to make it easier to run multiple servers... it'd be awesome if you took advantage of that. Don't know about how big a beast is needed, but I'd be happy to chip in some coinage to make it happen. Would hate to have it go down in the middle of some deal when I'm on the run...

Hehe, if that wasn't a precise prediction … 

The server was unreachable for 2-3 hours, which is about the response time from the service provider. This reminds me that it is about time that I run a second redundant copy. However, everything is back to normal.