maemo.org - Talk - my modified n900 - "normal" usb port and solar panel

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- - my modified n900 - "normal" usb port and solar panel (https://talk.maemo.org/showthread.php?t=90460)

Re: my modified n900 - "normal" usb port and solar panel

Quote:

Originally Posted by joerg_rw (Post 1352443)

You'd be surprised what even a small PV-cell can do when no load (device shut off, battery full and cut out due to protective circuit kicked in) and you give it a flash from a photography electron flasher.

Estel is absolutely right with his concerns. I'd like to add concerns about USB2.0 electrical properties getting messed up by your rework, resulting in data errors or even complete failure to establish connections at highspeed (480Mb/s). Even some cheap USB cables can fail for highspeed when the building quality and cable are poor.

[edit] re your 2nd post: all that's reasonably hot-swappable in N900 is already made to support hotswap. uSD slot gets powered down when you remove the battery cover, so you don't destroy the uSD by removing it while powered. SIM is useless to hotswap anyway. So what's the rationale of your hotswap plans? I failed to get the point.

[edit2] With sufficient electronical expertise you could create a convenient way to hotswap the battery, but the needed know-how is not trivial. To give you a starter: you MUST NOT parallel-connect two LiIon cells with differing charging level.

/j

The point of making the slot hot-swappable means that i don't have to remove the battery cover to remove the card. Something like nokia n95 style. But i'll have to find the switch that power down the card slot when battery cover is removed, and connect it to the new card slot (n97's) so when pushing the card inside to have a similar effect with removing battery cover. Remeber at nokia n95 when you pushed the card inside the slot for removal, it appeard something like "closing applications" and then "remove the card".
That is what i want from n900. Remove the card WITHOUT removing the battery cover.
P.S. Making sim card slot hot swappable sounds like a good idea. Thanks joerg_rw!

Re: my modified n900 - "normal" usb port and solar panel

Quote:

Originally Posted by joerg_rw (Post 1352443)

SIM is useless to hotswap anyway

This is the only point on which I disagree with Jörg. My previous phone, Treo 600, had a hot-swappable SIM and I found it very useful. In fact I find it very annoying that all other phones force me not just to turn them off but worse, take the battery out just to replace the SIM. Having said that, if Nokia made it that way then I suspect that making the SIM hot-swappable would be a matter of more than just bringing the contacts out. It might require some software changes too.

Re: my modified n900 - "normal" usb port and solar panel

Quote:

Originally Posted by pichlo (Post 1352480)

[...]Having said that, if Nokia made it that way then I suspect that making the SIM hot-swappable would be a matter of more than just bringing the contacts out. It might require some software changes too.

Exactly, that's why I said it's useless.

/j

Re: my modified n900 - "normal" usb port and solar panel

Quote:

Originally Posted by ryu1 (Post 1352453)

[...] But i'll have to find the switch that power down the card slot when battery cover is removed, and connect it to the new card slot (n97's) so when pushing the card inside to have a similar effect with removing battery cover.

This is a Reed- or hall-sensor engaged by the magnet in cover which holds the kickstand. It's an electronic component that needs a tiny bit more than just soldering two wires to it, to replace it with a mechanical switch inside a slot-in uSD holder. You'll at least need a cmos gate plus some ESD protection measures to avoid frying the gate and/or the CPU itself when something odd happens to your slot-in uSD-holder, like you discharging your wool pullover to the slot.

/j

Re: my modified n900 - "normal" usb port and solar panel

Quote:

Originally Posted by pichlo (Post 1352480)

Having said that, if Nokia made it that way then I suspect that making the SIM hot-swappable would be a matter of more than just bringing the contacts out. It might require some software changes too.

But if i brig the contacts out, then turn gsm off ( i use a menu applet to turn on/off gsm, wlan, bt) remove the sim then insert a new sim then turn gsm on again. Wouldn't that work? Maybe i'll test that tonight :p

Re: my modified n900 - "normal" usb port and solar panel

Quote:

Originally Posted by joerg_rw (Post 1352484)

If that's the case, the solution is WAY more simple the that. :D
All i have to do is take that magnet out, and stick it to the kickstand, so when i open kickstand that small magnet comes out with it.
It is much more simple to open the kickstand to mount/unmout sd card, then to remove the whole battery cover (in my opinion)

Re: my modified n900 - "normal" usb port and solar panel

GSM: yes (you also might want to check dual-SIM SIMswitcher-app of peterleinchen)
kickstand: well, if you like it that way
/j

Re: my modified n900 - "normal" usb port and solar panel

Quote:

Originally Posted by joerg_rw (Post 1352493)

GSM: yes
kickstand: well, if you like it that way
/j

It is the easyer way :p. Open/close kickstand = mount/unmount sd card. All left to do is stick that n97 card slot on top of n900's one, and make a nice cut in the battery cover. (your idea is better joerg, but there is no more room inside n900 for CMOS gate, not to mention ESD protection)

About sim card slot, you are sayng it will work that way?

Re: my modified n900 - "normal" usb port and solar panel

(gsm) see http://talk.maemo.org/showpost.php?p...&postcount=104
It seems under certain circumstances (re PIN) the modem can handle swapping the SIM, and you can make maemo side software to handle it as well, by e.g killall csd. There are still several problems like operator name shown etc. Check out peterlienchen's simswitcher app for how to handle all that, you might patch it for your purpose

ps: thanks for 4444 thanks to whomever it been, I owe you a schnaps
/j

Re: my modified n900 - "normal" usb port and solar panel

Remember, that by moving magnet into kickstand, you cut yourself out from using super-effective physical device separation for swap (i.e. using swap on microSD, to avoid I/O races with home activity).

It wouldn't be funny to, practically, pull your ram stick out of device, everytime you open kickstand (that's how device feels it, when you have swap on microSD, and microSD disappears, instantly).

/Estel