Stuffing Serial Bluetooth Module Inside C1k Casing, share your success stories ... Options

[albertr]

Since I haven't yet read/seen any posts about success stories on the subj (except for someone who claimed he added a usb bt dongle, but didn't support it by any tech info/pics), I'm getting ready to perform a first surgery on my C1K. Time permitting, I hope to do it sometime next week (maybe on July 4th holiday weekend).

Here's a few thoughts I have on the subj:
- There's a ffuart wired up to a port on the back of the C1K (so-called sharp i/o port) that has all modem control lines. I'm leaving it as a last resort (if everything else fails), since I want to retain it for rs232 comm.
- There's a btuart in PXA270 that has CTS/RTS control lines, but it's unknown if Sharp traced it on PCB. I would guess that it would make sense to have it traced just in case, i.e. planning for future models with built-in BT, but with Sharp you never know...
- Well, it leaves us with stuart that is wired up to IRDA transmitter/diode, but doesn't have any control lines, so hardware flow control is not possible.

If btuart lines can't be traced, either rs232 or irda has to go. Personally, I don't use IRDA myself, so for me the choice is clear. But not having hardware flow control leaves us with a challange of fighting high interrupt latency of bloated Sharp's kernel to avoid fifo overruns. I took a look at Sharp's serial driver, and as usual with sharp it's ... well, not good. I had troubles with overruns even at modest speeds. Now, the good thing is that it;s Intel PXA270, not Sharp's proprientary hardware, so full tech specs are available. I spend a few hours on "unsharp'ing" the serial driver, so now it seems to run ok. I tested it @ 460800 and not getting overruns anymore. I still need to test it @ 921600 and implement suspend/resume hooks, maybe add some hooks to front LED to show activity, etc.

Anyway, just thought it would be useful to have a dedicated thread where we all can share tech info and success stories. Please feel free to contribute... and I'll update you on status of my surgery.
-albertr

[albertr]

Ahh, right! Sorry, I completely overlooked that...

Too bad that GPIO 42 & 43 pins are used in PXA250-based clamshell Zauruses. It looks like they are *NOT* used on PXA270-based Zauruses (scoop's GPIO used instead), but tracing them might be a challenge.

-albertr

[speculatrix]

Ahh, right! Sorry, I completely overlooked that...

Too bad that GPIO 42 & 43 pins are used in PXA250-based clamshell Zauruses. It looks like they are *NOT* used on PXA270-based Zauruses (scoop's GPIO used instead), but tracing them might be a challenge.

-albertr

what's the difference between the pxa250 (700 and 5600) and pxa255 (760,860)? This discussion is making me excited about the possibilities of squeezing a BT module inside my 860!

useful table:
http://tuxmobil.org/pda_survey_sharp.html

--- edit ---
ah, apparently the 255 has 30% lower power consumption, and a faster clock speed, and a faster bus (200 not 100 MHz).

This post has been edited by speculatrix: Sep 1 2005, 07:11 AM

[2x4ever]

ah, apparently the 255 has 30% lower power consumption, and a faster clock speed, and a faster bus (200 not 100 MHz).

This is the only difference i think. And you will suffer the same troubles which i have with my C700.