maemo.org - Talk - The Ludicrous N900 Powermat Mod

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- - The Ludicrous N900 Powermat Mod (https://talk.maemo.org/showthread.php?t=72753)

Re: The Ludicrous N900 Powermat Mod

Nice to see more modders in here, good work.
If it had not been for my pretty powerful external/internal charger i would have made wireless charging myself.

But like the fact that you use a stock product and mod it with the N900, just like me, buy one thing, use it for something probably not intended :D

Re: The Ludicrous N900 Powermat Mod

Quote:

Originally Posted by ~phoenix~ (Post 999658)

where can i get theese powermat things??

http://www.powermateu.com/pm_uk/

They're also on Amazon and ebay.

Re: The Ludicrous N900 Powermat Mod

Another thing, if you make a dual mod, with other battery's then the scuds (because of the thickness), you should be able to integrate the powermat receiver module inside the cover, like if you use japod's or polarcell.

Re: The Ludicrous N900 Powermat Mod

Been considering something like this since I saw a mod for another phone. On Hackaday.

Quote:

Originally Posted by Wonko (Post 999642)

Alright... [B]I took the Powermat receiver of an Iphone 3G Powermat set. You can pretty easily break it off the casing without damaging it.

So, this is from an iPhone powermat. Dont those things need their data lines at certain voltages to charge properly?
If thats the true for the powermat charger, there must be something on the receiver or maybe the back that does the shorting. Any chance of reusing it?

Re: The Ludicrous N900 Powermat Mod

Would like to try this, but I'm going though airport security soon and I'm sure all them wires popping out might turn a few heads.

Re: The Ludicrous N900 Powermat Mod

Quote:

Originally Posted by yorkey (Post 999725)

Well, dunno about the iphone.
But there is the flat ribbon connector on the powermat receiver which connects to quite some pins of the iphone connector. From what I saw some of these are USB data lines indeed. Though, I have no clue what is happening on that lines. Furthermore, I am not that good in SMD soldering. Another chance to get this done could be to mess with the flat ribbon cable directly. Though, these things are pretty sensitive as well. Anyhow, my version is just a pretty crude, "hacked" together proof of concept. Maybe in some time there will be a better solution.

Edit: the iphone 3G Powermat receiver also has loop-through functionality for USB. So it "should" be possible to use this too instead of using a custom diode and a dip switch like I did.

Quote:

Originally Posted by jd4200

Would like to try this, but I'm going though airport security soon and I'm sure all them wires popping out might turn a few heads.

Heh, yeah, this is also one of my concerns. Well I think I'll have to reactivate an old phone to take with me on the travel. I don't like the idea of some airport security guy pulling apart my N900 and messing with the fragile cabling. ;)

Edit2: or even being pointed at with guns or being thrown at the floor with a knee in my neck... :eek:

Re: The Ludicrous N900 Powermat Mod

Quote:

Originally Posted by woody14619 (Post 999588)

WOW! Super! I would love this. I use an Otter Box on the outside, so removing or mangling the original back isn't that big of an issue if that's all the space it needs! Where are you connecting it internally?

It seems like the sender and the receiver need to be put very tightly next to each other in order for the charging to work.
I am not sure if it will work "through" that case.
Most probably you would need to also "mod" your otterbox case.

Re: The Ludicrous N900 Powermat Mod

Quote:

Originally Posted by Wonko (Post 1000176)

Thank you for the warning... I think I will order a set anyway and see what happens. I think I will also order a new back, so I have it, just in case I want to use it without the Otterbox in the future. ;)

I've wanted something like this for a long time, but always got hung up on how to connect it into the system without endangering/blocking the USB port. I plan on putting a micro reed relay (or maybe a low power opto-isolator?) in to short the data pins activated by current from pad itself, so it auto-closes the connection when it's powered by the pad. That should take less than 10-20mA for an opto-isolator...

Thanks so much for this awesome mod and the pictures. I love this phone, and the community around it!

Re: The Ludicrous N900 Powermat Mod

Quote:

Originally Posted by woody14619 (Post 1000194)

I plan on putting a micro reed relay (or maybe a low power opto-isolator?) in to short the data pins activated by current from pad itself, so it auto-closes the connection when it's powered by the pad. That should take less than 10-20mA for an opto-isolator...

Using an opto-isolator seems to work quite well. :) Thanks for that hint. I made an improved mod that uses such an opto-isolator (Optokoppler in German) to short-circuit +Data and -Data. I attached an image of the actual circuit I am currently using.
The diode BY 133 is used to protect the Powermat receiver from the USB +5V voltage and to prevent the opto-isolator being activated when the N900 is attached to a common USB port/charger.
Furthermore, I am now using the receiver part of a Powermat Nintendo DS Lite charger. This one is slightly thicker and requires more manual work in order to being attached to the N900 battery cover. Though it has the benefit that it is not as complicated as the Iphone 3G version and occupies a smaller area. I'll let you know how this one works out...

Re: The Ludicrous N900 Powermat Mod

Quote:

Originally Posted by Wonko (Post 999642)

Alright... of course all warnings etc. from the initial post apply as well ;)

I connect the whole shebang via USB. Though I am not using the USB port but rather the pads beneath the battery (see the first image).

I took the Powermat receiver of an Iphone 3G Powermat set. You can pretty easily break it off the casing without damaging it. Furthermore, it is internally connected via a flat ribbon cable which detaches easily.
On the second picture you can see where I identified GND and +5V (actually you get something around 5.2V from it). I accidentally fried the first GND soldering pad located next to the +5V pad so I used another GND pad which can be seen in the background.

Excellent! Couldn't find complete pinouts when I did my inductive charging mod, so I added a Li-ion charger to directly charge the battery -- now I can connect to the USB pads and BME can stop being a ****** about low-battery warnings.

Check my version out in my sig, and welcome to the very exclusive inductive-charging club! :)