Quote:
Hmm... so recording everything isn't that much data. That's good, and simplifies things. But yeah, I forgot that the empeg keeps the hard drives read-only, and spun down most of the time. I guess there's probably a way to hold the data in memory until a certain amount has been recorded, then write it in chunks to the hard drive. That would help with keeping the drive from spinning all the time, which wouldn't be good for it. How much memory is there for apps to use? Probably not much. As for the R/W thing, that's a bit trickier...

The whole job can be done with a moderate bash shell script running on the empeg. You can use the Hijack ;@EXEC_ONCE feature to (re)launch it at boot. The script could create a ramdisk device, and then use dd to copy from the serial port to a temp file on the ramdisk.

Each time the file hits a defined size (eg. 1MB, determined by parameters to dd), the command would exit, and the script would then continue: remount the disk RW, use cat to append the temp file's contents to a master log file, and then set the disk back to RO, nuke the temp file, and loop again.

The tricky bit is ensuring the drive gets set RO before any power-off of the player, as otherwise a possibly lengthy fsck will cripple it at next boot. There's a config.ini setting somewhere that controls power-off after the ignition turns off, and one could tie into that.

This could take a couple of hours for a reasonable UNIX script writer to get working correctly.

Me? I just use a laptop for stuff like this!

Quote:
I couldn't just re-partition one of the drives however I like? I don't mind losing my data, as I can put it all back fairly easily.

Quote:
Why not just pickup one of those nifty IDE>CF adapters, grab a decent size cf card, and setup the scripts to write directly to the flash device?

Quote:
The tricky bit is ensuring the drive gets set RO before any power-off of the player, as otherwise a possibly lengthy fsck will cripple it at next boot.

Quote:
Supposedly there is a spare 32 meg partition reserved for stuff just like this.

Quote:

According my revised calculations (this time somewhat based in reality), the NMEA data will come to about 2 megabytes per hour. Not a lot, but when you're talking about 6 weeks of driving, 32 megs won't be enough. On the other hand, assuming I go the path of making a RAM drive for temp storage, even if the RAM drive is only 1 meg in size, that means I'll only need to write to the hard drive every half hour or so (plus right before the script closes). In which case, it doesn't seem like it would be too risky to have the normal data partition set to RW for a couple of seconds every half hour. Does that make sense?

Quote:
According my revised calculations (this time somewhat based in reality), the NMEA data will come to about 2 megabytes per hour. Not a lot, but when you're talking about 6 weeks of driving, 32 megs won't be enough. On the other hand, assuming I go the path of making a RAM drive for temp storage, even if the RAM drive is only 1 meg in size, that means I'll only need to write to the hard drive every half hour or so (plus right before the script closes). In which case, it doesn't seem like it would be too risky to have the normal data partition set to RW for a couple of seconds every half hour. Does that make sense?

Quote:
And although I can hack my way through shell scripting, if it turns out I have to write REAL code, I'm pretty much screwed.

Quote:
If cost isn't much of a concern just get one of these for $150 and your set.

Quote:
i already have the Empeg, so why spend another $60 for a device I'll only use once?

Quote:

From what I've heard here, it seems like I should be able to get this working with a not-too-complicated script. I'll be out of town for the next two weeks, but will start writing the script when I get back. Thank you all for your help, and I'll be sure to bug you again once I start the code writing!