View Single Post
Estel's Avatar
Posts: 5,028 | Thanked: 8,613 times | Joined on Mar 2011
#132
Originally Posted by phr View Post
This sounds great. I'd be interested if for no reason just to support the project spirit.
Thanks a lot for Your kind words and feedback! BTW, for everyone who likes to support this project, please consider pre-ordering. Of course, I can't guarantee when exactly it will be available, but as a thank-You for monetary supporting this (which already gave a nice boost on project's speed, as two nice guys pre ordered full body replacement, and another nice Maemo user ordered backcover), You'll be able to provide custom logo/extengraved on backcover +, of course, being sure to be amongst first few that receive final body/backcover

Originally Posted by phr View Post
1) I'm ok with either single or dual battery. I like the idea of 2 batteries in the same plane instead of stacked, to keep case thickness down.
Probably won't happen, as it would require complicated tricks or making device wider/longer. Aim of this project isn't to transform N900 into tablet-sized thing with 3.5'' screen - for most people, additional thickness is less of a problem, than a longer/wider device. Also, there is always a possibility to order flat backcover.

Of course, as I've answered to Huz, if someone prepare designs (applicable to linuxcnc) and cover costs, I'll gladly make them on my CNC for those willing to get such different kind of things.

Originally Posted by phr View Post
2) I was a proponent of full sized SDXC but I think it's not worth it any more. 32gb microsdhc is dirt cheap and 64gb is affordable. Full size exists in 128gb but is it worth it? Dual micro slots is probably better than 1 full size if it comes to that. (But probably not feasible).
Full sized SD card are much less expensive - especially, at earlier stage - comes first when new capacity is introduced, offer better speeds, live through more cycles, etc... Dual card setup is not possible, it doesn't work that way. You would need 2nd SD interface on N900 itself.

Originally Posted by phr View Post
4) It's not worth messing with 18650's instead of flat cells (which aren't that expensive). Flat cells of high capacity are available. In fact it might be nice to have mounting option for add-on layer holding a 4000 mah flat cell like the one in the Open Pandora palmtop. It could be set up with a 5v step-up converter so it would charge the phone like an external charger, rather than going directly to battery contacts. But it would still be a solid piece, no external wires etc.
Flat cells that *really* offer advertised capacity are quite hard to get and much more expensive. We're talking about real capacity, not what is put on label. See battery thread for more details.

Converted to 5V is a no-go - losses in efficiency + why the hell would we want that? + if someone really need it for any reason, custom converted can be plugged to batteries itself, even before protecting PCB (again see battery thread and dr_frost_dk mods to add plug connected directly to cells)

Originally Posted by phr View Post
One thing I've wanted for ages is a phone powered by commodity AA NiMH (not lithium) cells. Yes they're less efficient but they're cheap and easily available. Good AA's are about 1.2V 2500 mAH so two AA's have about 1.4x the energy of a BL-4J, I think. It could be possible for the external layer to use more AA's, maybe even 6 or so of them. I still have a 6AA holder for my ancient Motorola analog flip phone and it was a practical device.
Even putting aside fact that it would be completely incompatible with N900's battery interface/charging chip/ etc (= not possible/feasible), it's also not true. You need 3 NiMH to get average voltage of single LiIon, so 3 2500 mAh NimH's would give You *only* 2500 mAh @ 3.6V. Of course I'm putting aside "plentora" of other problems. +, NiMH's are hurt by not going through full charging cycle, ages much quicker, etc, etc... LiIon's in mobile world is actually very reasonable.

Originally Posted by phr View Post
5) I like the idea of threaded hole over the camera (27mm? 37mm?) to allow screw-in lens accessories available for digicams/camcorders (telephoto/wide angle converter, filters, etc). Might be interesting to also supply some kind of remote flash trigger.
Not going to happen - results would be poor without properly considering optic's characteristic on given distance from lens, and I'm no optic's engineer.

Originally Posted by phr View Post
One thing I wonder, will the metal case interfere with GPS reception? Same for Bluetooth, wifi, etc.?
Originally Posted by immi.shk View Post
good point
but i guess it they are mostly located on main body..

plus metal should increase there efficiency instead of decreasing it..

i guess- if it does interfere that section could be left plastic.. or the reception antennas could be shifted(soldered + extended) to camera hole(larger backcover) since its useless till now and not visible directly, and its material could be changed to whatever increase th reception..
also whatever design we are gonna get a big metal kickstand it could also do the purpose
It was asked before - of course, it would block (shield from) all signals (including gsm), if done wrong way. Fortunately, we will manage to do it proper way, without loss of signal quality or even boosting it

Originally Posted by immi.shk View Post
also a single layer of cover(transparent Poly-pack or lamination) and the device is splash-resistant & still 100% usable..
...and would heat like hell, due to insulating, air-tight layer I would be afraid to use it with anything more than 500 mhz, if encapsulated like that.

/Estel
__________________
N900's aluminum backcover / body replacement
-
N900's HDMI-Out
-
Camera cover MOD
-
Measure battery's real capacity on-device
-
TrueCrypt 7.1 | ereswap | bnf
-
Hardware's mods research is costly. To support my work, please consider donating. Thank You!

Last edited by Estel; 2012-05-20 at 16:56.
 

The Following 4 Users Say Thank You to Estel For This Useful Post: