LinuxOniPaq

intro

I got an iPAQ H3660 on ebay that was 'broken'. After reconnecting the touchscreen cable to the mainboard it seemed to work fine. now that it works i need to liberate the poor thing from winCE (as in wince in pain). following the docs on hh.o it was pretty easy other than getting a working serial connection. turned out i was over thinking it...

serial connection

though it's not mentioned on the wiki the iPAQ (at least the h3660) has a builtin rs232 level shifter, thus using an additional one (as is common with embedded uarts) f's it all up. I was getting jibberish out of the serial port until i connected the iPAQ serial lines directly to my computer (no rs232 transceiver). eventually i got out the multimeter and noticed -5v on the Tx pin - not TTL at all so i figured the level shifter must be built-in. a little more searching revealed that it was. i was sure i needed RTS, CTS but my faith in rs232 has been restored (3 wires is more than enough).

bootldr

haven't got to explore all the features of the new version but this provides a serial console to upgrade the linux distro on the iPAQ as well a boot wince (why would you want to?) or really any other ELF file compiled for the SA1110.

To create a serial cable hack your usb cradle with the following pinout. Remember you only need point to point wiring NOT a level shifter like the max232.

DB9	iPAQ Header	Function (wrt the iPAQ)
2	7	Rx
3	8	Tx
5	GND pad	Ground

You can also solder to CON2 but the pinout is different. Look at the HOWTO for the mapping.

outro

at some point i'll add some pics of GPE running. It has some cool features like being able to rotate the screen into any orientation (well in 90 deg increments anyway). Seems like tying that into an accelerometer would mean that you could reorient the screen solely with gestures (turn the pda on it's side and the screen rotates to match).

but basically since I now have linux running and was able to hack the cradle to add in the serial port I've lost interest. Working devices are no fun...maybe i'll break it again so it'll be of interest again.

-- ChristopherPepe - 02 Aug 2006