Broken MicroUSB idea: Creating a new connection
I've read about somebody wanting to try this, or perhaps achieved it, but can't find where.
http://www.cpkb.org/wiki/Nokia_N900_pinout and http://www.cpkb.org/wiki/Micro-USB_pinout Using these, the back of the pcb of the n900: http://www.cpkb.org/images/thumb/9/9...900_pinout.jpg Microusb cable: http://www.cpkb.org/images/thumb/0/0...b_pinout_2.JPG * 1 - (black) GND / ground * 2 - * 3 - (green) Data + * 4 - (white) Data - * 5 - (red) VDC / plus / +5V * 6 - shield Using this data: Is it possible to create a new Microusb connection? Where my microusb connection was, there are no more metal solder points to be able to repair the microusb port. Unsure 100% of the following: Line up TX with Data + Line up RX with Data - GND with GND But then where does one obtain the positive voltage (usually 5v). On the cable this is VDC +5v, but the battery positive cannot supply this voltage.VCC according to the link "Common Collector Voltage - main power supply ( usually 5V )". But would this work? the provided link doesnt actually specify where VCC is. The cable would then be routed to where the microusb was. So I'[d attach a new microusb port, with the cables being soldered from the new microusb port, to the connections above. edit: I already have a desktop charger. I also use TinySMB to transfer my files to and from pc. The only reason I'd have for doing this is if I want to reflash. |
Re: Broken MicroUSB idea: Creating a new connection
http://talk.maemo.org/showthread.php?t=54762&page=2
http://talk.maemo.org/showthread.php?t=45385 Nice to have some good tutorials for the USB fix. Thanks all :) |
Re: Broken MicroUSB idea: Creating a new connection
yep read those. however if you read my post again, ive mentioned i have no metal tracks on the pcb for the microusb anymore. which means i cannot use that area. hence my idea of making a new connection from the areas ive listed above
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Re: Broken MicroUSB idea: Creating a new connection
That's an fbus or mbus connection, not USB, by the looks of it. I think your best bet is to solder to the red and black components as indicated in this image http://talk.maemo.org/showpost.php?p...3&postcount=12
If you've torn those off too, it's probably too late. |
Re: Broken MicroUSB idea: Creating a new connection
could those rx/tx lines be used as TTL serial? that would open a lot of new areas for the N900.
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Re: Broken MicroUSB idea: Creating a new connection
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But the question is, where to get the +5 volt connection from? |
Re: Broken MicroUSB idea: Creating a new connection
IIRC these are debug/UART/serial ports, not USB ports.
Who knows if they're DC5V. You'll need a USB host controller, and not any random pins like JTAG/GPIO. Although, if they /were/ GPIO, anyone want to try strapping an Eye-fi card to them? |
Re: Broken MicroUSB idea: Creating a new connection
Quote:
Thanks for your answer... |
Re: Broken MicroUSB idea: Creating a new connection
1 Attachment(s)
Actually, you do get access to the USB connector via these pads.
I managed to charge the battery having +5V and GND connected to a 5V power source. Please be aware that this is highly experimental and you do this all at your own risk! By messing with your device in this way you'll for sure loose warranty! Furthermore, you may damage or even destroy your device! Having said that, lets move on: In order for the charging to begin +Data and -Data need to be connected (via some resistor ~2.5 Ohm) prior to connecting the power source. Else simply nothing happens. ;) Note: I measured whats going on with the default power supply on +Data and -Data and it showed a resistance of 2.5 Ohm. I used a 2.2 Ohm resistor and also tried to simply shorten +Data and -Data. In both cases the battery started charging after connecting the power source. I attached an image of the pins I used. Edit: I added my stuff in orange color. GND of course still is the same. Please note that: Quote:
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Re: Broken MicroUSB idea: Creating a new connection
Hi,
good work, Wonko! :) Anybody got a working USB data connection over the pads in Wonkos picture? I tried it, but without powering the device over the USB pads, but with battery. The N900 never appeared in /var/log/messages. Could it be possible, that an USB data connection needs also external USB power? Maybe to activate or power up some controlling chip? |
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