OESF Portables Forum
Everything Else => General Support and Discussion => Zaurus General Forums => Archived Forums => Hardware Mods => Topic started by: speculatrix on October 07, 2008, 07:25:01 pm
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a very neat little device!
http://www.buygpsnow.com/Canmore-GT-730F-U...port__1037.aspx (http://www.buygpsnow.com/Canmore-GT-730F-USB-GPS-Dongle-with-A-GPS-Support__1037.aspx)
I saw this via an engadget posting.
http://www.mydellmini.com/forum/integrated...ini-9-t167.html (http://www.mydellmini.com/forum/integrated-gps-on-my-mini-9-t167.html)
shame but I think it'd be too big to fit inside a Zaurus....well, maybe inside a 1000.
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As awesome as that would be (even from somebody who doesn't use GPS stuff much), doesn't having anything between the GPS and the sky kill performance?
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The latest chipsets are ridiculously sensitive; I've got a BT gps unit with a MTK chipset and it blows my older SirfStarII out of the water! Decent locks indoors, in pockets, etc. That said, it has a decent antenna; any GPS unit with an antenna small enough to fit inside the Z is going to suffer badly.
Better to use a BT GPS, I reckon; lower battery drain on the Z, and you can use it with the Pandora once it ships
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I have sometimes wondered if there is space inside the LCD half of the Z; if there was, couldn't you put a GPS in there behind the screen? ok, it'd be a difficult mod, especially to get the wires down into the main half, but it'd be very cool!
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I have sometimes wondered if there is space inside the LCD half of the Z; if there was, couldn't you put a GPS in there behind the screen? ok, it'd be a difficult mod, especially to get the wires down into the main half, but it'd be very cool!
I would be more worried the heat from the GPS module killing the LCD
Late
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The latest chipsets are ridiculously sensitive; I've got a BT gps unit with a MTK chipset and it blows my older SirfStarII out of the water! Decent locks indoors, in pockets, etc. That said, it has a decent antenna; any GPS unit with an antenna small enough to fit inside the Z is going to suffer badly.
Better to use a BT GPS, I reckon; lower battery drain on the Z, and you can use it with the Pandora once it ships
Ah, I see. So it might work if you soldered a larger antenna on an ran it around the Z's internals?
My SirfStarIII works really well (outside/in the car, at least, and I have no other GPSs to compare it to, other than the N810's infamously lousy one, but I digress...). It's also USB, and doesn't need proprietary drivers (just a pl2303 module), so my Pandora is going to be set as well.
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I think too this module would be too big. on closer examination, the GPS is a serial device and it uses a usb-serial bridge, so it'd be better to bypass the USB and connect it directly to an internal serial port. so, heres some more such modules:
http://www.rfsolutions.co.uk/acatalog/GPS_Systems.html (http://www.rfsolutions.co.uk/acatalog/GPS_Systems.html)
I am interested in this because I still think it's possible to boost the functionality of my 3100 by implanting a bluetooth or wifi module.
Also, am trying to design a micro-keyboard dock for my nokia tablet, using a brando supermini keyboard, one of those LiIon battery packs with usb/+5V out, a v small hub, a 3G usb modem and a usb GPS.
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It's far too big to fit inside Zaurus. Maybe inside Akita into space reserved for HDD. In case of Spitz I guess that you will get antenna and module on one larger PCB without any chance to fit them together into Zaurus. Space inside display is very small or well shielded.
If you really want to fit GPS inside, you may want to try separate module and separate antenna, connected with a thin HF cable (ideally buy an assembly with UMSMA connectors on both sides). You may want to try very small U-Blox or Wi2Wi modules.
But even with a sensitive GPS, you may want to prefer external GPS connected with Zaurus via Bluetooth. You could comfortably work with your Zaurus putting GPS into the best signal place. With a good external GPS logger you have another advantage - battery life: 30hrs for GPS logger, maybe 8hrs logging by Zaurus.
FYI, here are larger empty areas inside Spitz/Akita Zaurus:
- Akita only: CF sized space. Open from one edge.
- Above CPU shield: 30x50x2.8mm May cause thermal problems. Open from one side.
- Between plastic HDD cover and keyboard shield: about 30x15x4mm. Nearly completely shielded.
- Above the NAND flash: about 14x22x8mm. Partially open from one edge.
- Small but long non-shielded area in edges of the device and inside the battery cover.
- inside the decorative cover around the display joint point. Shielded by metalic surface.
For more see updated photos. See my signature for more.
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Speculatrix: Space inside display is very limited - on both left and right sides there are PCB (display controller and power). And it will be well shielded if you close the lid.
Regarding the DS-310FS: This module may fit into both Akita and Spitz, at least into the space in the plastic cover of HDD. Antenna has to be elsewhere. You will need a special thin HF cable - either using flying wires (a bit ugly) or a small daughter board with (low profile) UM-SMA connector.
Then you need to wire one quadruble resistor under the CPU cover (see albertr's description and my photos) and then attach serial cable to pins under the HDD.
Also attach non-regulated battery/AC voltage to prevent cold start (see the spec).
Last you need to get regulated 3.3V plus its control. Regarding the control, there is free GPIO 40 and probably 10, repurpose-able BTRTS and BTCTS, several nearly ununsed GPIOs on diagnostic connector and finally several free SCOOP2/AKITAIOEXP pins. Adding a special switching IC (special transistor) will fit your needs.
Regarding the 3.3V power:
From CPU changer (step-up to 5V, then back to 3.3V, the same is wired to IOPORT): Possible, but you are limited to 50mA (and even this may shut down your CPU with a peripheral connected to IOPORT). Hopefully, removing batteries for a while returns Zaurus back.
From CF/SD step down: Surprisingly it is step-down only with attached 2.8V detector, which seems to be in contradiction with CF standard, which requires at least 3.15V for regular operation. But my CF seems to work even with lower battery. It needs to be verified, whether it is possible to keep it on, when no CF/SD is attached. (Well, I don't understand the power design here.)
From HDD step up/down changer (Spitz only): It seems to give enough power and it is bi-directional. It needs to be verified, whether it is on if HDD is down.
From a custom changer: There are even two unused changers on the PCB, intended for Mitsumi Bluetooth module. But one has to find, how they should be connected. For Spitz, there is not enough space to solder it there.
If anybody will do 3.3V power voltage research inside Zaurus, please let me know. I am searching for a solution for BT/WLAN.
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My SirfStarIII works really well (outside/in the car, at least, and I have no other GPSs to compare it to, other than the N810's infamously lousy one
I thought the problem with the GPS in the N810 had been solved - it was because the date/time settings were completely screwy which meant the GPS was unable to get a hot fix.
Thanks to everyone for their ideas, it looks as if we'll need to wait for a newer generation of even smaller GPS chipsets before we can create a Zaurus 1000G or 3x00G!
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Thanks to everyone for their ideas, it looks as if we'll need to wait for a newer generation of even smaller GPS chipsets before we can create a Zaurus 1000G or 3x00G!
No, we don't need to wait. Moderm modules sized 12x12x3mm are small enough to fit inside Zaurus. Antenna is the problem. For example OpenMoko did not use compact chip antenna, but they used classical dipole, smartly placed inside the cover. It needs smoe of experimenting (or a lot of complicated computing), but it may be usable for Zaurus as well. Making a dipole needs only few wires.