Custom Cf Card Design

[wsuetholz]

Hello,

As you may have noticed from my prior posts.. I am interested in trying to get the Embedded Works Wi-FI/Bluetooth module working with the Zaurus.

In regards to that, does anyone have the interest/time to develop a design for a CF card that would have the proper Molex 54722-0607 mating connector and a SD card slot, heck maybe even add a GPS receiver as well since the part from Embedded Works EW-WMBGMR01 is really small.  I actually think that they get it from RoyalDigital, Inc. since I see a made in Taiwan label at EW.

This would be the ultimate expansion card for devices with a CF slot....  If it's doable.

I am not real hardware savvy, but most of the software work to interface with the Marvell chipset is done, and they are working with I think Koen to have the CF portion working.  If it could be made mostly compatible with the devices that are being planned to be used in the PP, then the drivers could be reused for the PP when it gets built.
 
No, I'm not suggesting squeezing the GSM phone on as well, unless you think it could be done :-)

I know that you can combine memory and WI-FI in a CF card since SanDisk did it with their 128M/802.11B card, don't know how they did it, but it showed up as two sub devices when the CF card was plugged in.

Bill Suetholz

[iczer3]

Dear wsuetholz,

Sorry to inform you that you cannot just wire 2 cf cards together to
form multifunction card. You need a selector to select between the
two cards. That bit requires both hardware (a splitter IC) and software
(implemented in both the attribute and common memory space).

basically you need in card space stating that you have 2 or more functions,
their respective memory/io address ... etc.

br,

felix.

[utx]

But at least http://www.embeddedworks.net/ and http://www.unex.com.tw/ produce BT+WLAN combo modules. If they have spare UART port there (I don't know), there is a chance to add GPS or GSM there easily.

I am also interested in purchasing of a CF combo, which fits inside Zaurus without extender (or with a movable antenna: good signal - antenna inside, bad signal - antenna outside the Z body).

[speculatrix]

I have often thought about an I/O expander for the Z which uses the CF slot as an interface, to provide
- a bunch of general purpose I/O pins
- ADC/DAC functions for stereo sound input or oscilloscope analogue capture
- TTL/CMOS logic level serial, I2C or SPI bus for connection to eeprom, gps etc

it could be part of a docking station or expansion sleeve.

unfortunately my embedded electronics knowledge is a bit rusty, and my time too limited to explore it. In a similar post to this, here on the forum, I commented about the Handspring palm compatibles which had a slight variation on the PCMCIA interface to take springboard modules, we already do this with the CF slot for wifi, bluetooth, gsm/gprs, so I think all of the above is possible, but whether it can be done cost effectively is another question!

[utx]

I have often thought about an I/O expander for the Z which uses the CF slot as an interface, to provide
- a bunch of general purpose I/O pins

I guess you can have at least 5 of them on IOPORT on all Z models (except pre-production SL-C3000 pieces), if you will repurpose serial lines. See my Z hardware pages to see what is actually connected on SL-Cxxxx.

- ADC/DAC functions for stereo sound input or oscilloscope analogue capture

Wait. I guess that stereo input can be done (at least on SL-Cxxxx) at least by two other ways:

If you look at the connector, you see two pins connected to ground shield. One is ground, second is insert detection. Insert detection is multi purpose pin, which can be also turned to RINPUT3. With a slightly modified 4-ring jack, you can reach this pin separately. I would expect lower quality sound however - measurement pin must be connected to power source and I doubt that it is noise-free.

Also ring2 is connected to D/A converter. Actually, CE-RH2 remote is only a set of resistors and ring2 is a simple resistance meter. This D/A is probably slow for audio recording.

Far the best would be a hardware modification: It seems, that parts for the right input are nearly completely soldered on the PCB, but for some reason RINPUT1 is connected to GND, not to right jack pin. It looks like a differential input (but by grounding of one side, it became assymetric and unusable in such way).

There is my guess: Remove RINPUT1-grounding (coil?) near the connector. Find a place, where you can connect RINPUT1 to the right jack line (with a bit of hope there may be prepared a place for the zero resistor). And finally solder protection capacitor. (MOD IS UNTESTED! NO GUARANTEE!)

If this will work, you could get a very good portable 24bit/96kHz stereo recorder.

- TTL/CMOS logic level serial, I2C or SPI bus for connection to eeprom, gps etc

According to PXA270 documentation, both SPI and I2C are somewhere inside the Zaurus.

it could be part of a docking station or expansion sleeve.

unfortunately my embedded electronics knowledge is a bit rusty, and my time too limited to explore it. In a similar post to this, here on the forum, I commented about the Handspring palm compatibles which had a slight variation on the PCMCIA interface to take springboard modules, we already do this with the CF slot for wifi, bluetooth, gsm/gprs, so I think all of the above is possible, but whether it can be done cost effectively is another question!
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Well, I never designed such small thing PCB as well and I don't ever know about high frequency problems one might meet there. I am just going to buy a better soldering lamp and starting to learn super tiny part soldering on something cheaper than Zaurus.

But there is also a completely different solution for "expansion board" - buy another tiny computer board, which has everything, what Z has not and connect both.