I have a feeling that BTstack is sometimes getting "killed" as I am starting or using applications that use more memory.

This is especially annoying as it means that I have to exist the application, turn off the keyboard, turn it back on, restart the Keyboard app... hoping that this won't happen again the next time I start another app.

Is this something that could be resolved in BTstack?

hi. don't know what's going on. the keyboard app is rather minimal, don't think it eats much memory. the BTstack daemon (BTdaemon) does not use (much) dynamic memory, so it should keep running.

can you try to understand what's going on and/or collect numbers on memory usage. please join the dev list for discussion.

This happens to me when I start some heavier application like SpellChecker or OmniFocus. I even had this happen just by browsing to a few sites. I have an original iPhone, so I would assume this is less likely to happen on a 3GS which has 256 MB of RAM rather than 128 MB.

Do you suggest that I post on the dev list about this? I am not an iPhone developer, so I am not sure that I will be able to help much, beyond providing the best description I can of the problem.

If the keyboard stops working, there can be 3 reasons: the Bluetooth connection broke, the BTstack daemon app crashed, or, the BTstack Keyboard app crashed or was killed. But the last is the most likely. Can you attach /tmp/hci_dumpk.pklg of your iPhone the next time right after the connection breaks? I hope to see which of those happened. The app getting killed is quite possible. You could enable Syslog and look for messages, or, install CrashReporter and check for reports.

An additional BTstack Keyboard daemon would reduce the used resources to a minimum. But that would require a major rewrite of BTstack Keyboard app. Not sure what other options are there. You could try to run the other "backgrounded" using Backgrounder which would allow for fast switching... a bit better but no solution.

@Matthias, how can I access the /tmp/hci_dumpk.pklg?

you can for example use iFile to send it by mail or do something else. it's shareware, but that is in the free version.