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My micro usb cable is no longer working (but my charger does), so im wondering if i should look for a specific usb to micro usb cable or anything.

Im asking cause the charger provides 2000 mA while the USB specification is around 900 mA.
 

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My micro usb cable is no longer working (but my charger does), so im wondering if i should look for a specific usb to micro usb cable or anything.

Im asking cause the charger provides 2000 mA while the USB specification is around 900 mA.
are you saying that while using the touchpad you are getting +900 mA (on battery monitor widget for example)? that sounds about right with max brightness. you are getting 2000; its just that 1100 of it are being used while the touchpad is on and running.
 

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yeah you do need a specific one my cable broke as well so i had to buy a new one, i went to ebay and typed in palm usb charger there was one at the top for 5.99 + free shipping thats the one i bought and it works for me
 

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NO NO NO NO NO NO and NO.

You DO NOT need a specific cable. Any usb to micro USB cable will work. There's nothing clever about the cable, only the charger is Touchpad specific because it produces 2A when most will only manage 1A.
 

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NO NO NO NO NO NO and NO.

You DO NOT need a specific cable. Any usb to micro USB cable will work. There's nothing clever about the cable, only the charger is Touchpad specific because it produces 2A when most will only manage 1A.
You're mostly incorrect. Yes, any usb to micro USB cable will "work". However, for it to charge correctly (charge faster than it loses charge), you need a USB Micro B cable (or "Micro-B"). Trust me, I ordered some Micro-A cables and they wouldn't fully charge with the TP turned on. Swapped them out for Micro-B's and now it works just like the OEM cable.

Refer to this post.. http://rootzwiki.com...firmed-working/

and from Wikipedia.. "USB cable, 5 ft (150 cm), with a Standard-A plug and Micro-B plug on its two ends."
 

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I'm sorry to say you are talking complete nonsense. Micro USB A male connectors will not fit into a Micro USB B female socket so your claim that they, "wouldn't fully charge with the TP turned on" simply cannot happen.

Obviously when I say "any" cable I do mean the one with the right connector!
 

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NO NO NO NO NO NO and NO.

You DO NOT need a specific cable. Any usb to micro USB cable will work. There's nothing clever about the cable, only the charger is Touchpad specific because it produces 2A when most will only manage 1A.
The "clever" thing about the charger is not that it produces 2A, but that it recognizes the proprietary signaling from the TP and allows the TP to draw 2A!
Only the TP barrel charger will do that.
 

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I'm sorry to say you are talking complete nonsense. Micro USB A male connectors will not fit into a Micro USB B female socket so your claim that they, "wouldn't fully charge with the TP turned on" simply cannot happen.

Obviously when I say "any" cable I do mean the one with the right connector!
OK, so I made a mistake.. the cables I bought weren't Micro-A (they had the right connector) but they absolutely would not fully charge the TP. This wasn't just a faulty cable because I bought 5 of them (different lengths) and none would fully charge. I could only get the TP to charge correctly by buying cables that were specifically called Micro-B. I got them from Monoprice BTW and it looks they've merged their product listings since I made that purchase. They actually let me keep the ones that didn't work on the TP and they work perfectly for my phone.
 

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The "clever" thing about the charger is not that it produces 2A, but that it recognizes the proprietary signaling from the TP and allows the TP to draw 2A!
Only the TP barrel charger will do that.
Not quite.There is no signalling from the TP and there's no intelligence in the charger. The Touchpad simply checks if the data pins have been shorted together and if so, attempts to draw full power from the charger. You can make a regular charger appear to be a touchpad charger by shorting the two data pins (the central two) together - either in the cable or the charger. Obviously if you do it in the cable then you won't be able to use that cable for data transfer but it's often easier to do that than pulling a charger apart.The circuit diagram from the official charger is attached, the resistor bridge seems to be optional if you are using an Apple charger (it already has a similar setup for iPads) and required if it's a generic charger.

To put this to bed once and for all: if you are using the official charger any Micro USB cable will work. If you want to use a 3rd party charger you will need to mod the charger to get the full 2A.
 

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Not quite.There is no signalling from the TP and there's no intelligence in the charger. The Touchpad simply checks if the data pins have been shorted together and if so, attempts to draw full power from the charger. You can make a regular charger appear to be a touchpad charger by shorting the two data pins (the central two) together - either in the cable or the charger. Obviously if you do it in the cable then you won't be able to use that cable for data transfer but it's often easier to do that than pulling a charger apart.The circuit diagram from the official charger is attached, the resistor bridge seems to be optional if you are using an Apple charger (it already has a similar setup for iPads) and required if it's a generic charger.

To put this to bed once and for all: if you are using the official charger any Micro USB cable will work. If you want to use a 3rd party charger you will need to mod the charger to get the full 2A.
I suspect that the resistor bridge is to allow the TouchPad to pull the charge it needs and still transfer data via the data lines.
 

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http://event.asus.co...010/ai_charger/

should work- with a touchpad aswell.

havent had a chance to test it though.

edit: use at ur own risk
It depends how it's wired. The way iDevices detect a mains charger is slightly different to the Touchpad. See the circuit diagram below.

With a standard cable you will get:
51k/(51k+75k) * 5v = 2.02v on Data +
51k/(51k+43k) * 5v = 2.71v on Data -

From the HP implementation above you can see that the TP is expecting the same value on both Data + and Data - namely:
300k/(250k+300k) *5v = 2.72v

If you use a cable with the data pins shorted together you effectively put the 43k and 75k resistors in parallel between +5v and data and also both 51k resistors in parallel between data and gnd. This will give you:

43k x 75k / (43k + 75k) = 27.3k effective resistance +5v to data
51k x 51k / (51k + 51k) = 25.5k effective resistance data to gnd.

Finally we can calculate the voltage on both data lines with this arrangement

25.5k/(27.3k + 25.5k) * 5v = 2.41v

You can see this is a bit lower than the TP is expecting but it might work for 2 reasons:
1. Resistors are notoriously vague in their value and can vary by +-5% quite easily.
2. The TP is likely to allow a reasonable range on the expected 2.72v

If you want an easy* way to get an iDevice charger to work with the TP, short the data pins at the TP end and cut data + on the charger end. This will make the Data - voltage (2.71v) appear on both Data pins which is what the TP wants from its own charger)

*easy is a relative term, good luck managing to short the pins on something as small as a micro USB plug


As ever, YMMV. I am not responsible for any damage you may cause.

PS. I'd like to say thanks to Wikitronic for his amazing circuit diagram tool at http://webtronics.googlecode.com Without the diagrams this thread would be much harder to follow.
 

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It depends how it's wired. The way iDevices detect a mains charger is slightly different to the Touchpad. See the circuit diagram below.

With a standard cable you will get:
51k/(51k+75k) * 5v = 2.02v on Data +
51k/(51k+43k) * 5v = 2.71v on Data -

From the HP implementation above you can see that the TP is expecting the same value on both Data + and Data - namely:
300k/(250k+300k) *5v = 2.72v

If you use a cable with the data pins shorted together you effectively put the 43k and 75k resistors in parallel between +5v and data and also both 51k resistors in parallel between data and gnd. This will give you:

43k x 75k / (43k + 75k) = 27.3k effective resistance +5v to data
51k x 51k / (51k + 51k) = 25.5k effective resistance data to gnd.

Finally we can calculate the voltage on both data lines with this arrangement

25.5k/(27.3k + 25.5k) * 5v = 2.41v

You can see this is a bit lower than the TP is expecting but it might work for 2 reasons:
1. Resistors are notoriously vague in their value and can vary by +-5% quite easily.
2. The TP is likely to allow a reasonable range on the expected 2.72v

If you want an easy* way to get an iDevice charger to work with the TP, short the data pins at the TP end and cut data + on the charger end. This will make the Data - voltage (2.71v) appear on both Data pins which is what the TP wants from its own charger)

*easy is a relative term, good luck managing to short the pins on something as small as a micro USB plug


As ever, YMMV. I am not responsible for any damage you may cause.

PS. I'd like to say thanks to Wikitronic for his amazing circuit diagram tool at http://webtronics.googlecode.com Without the diagrams this thread would be much harder to follow.
Everything you say here is correct, however, a shorted data line on a modded cable charges at a lower rate than one with correct resistor values.
I have made up every conceivable combination of cables and modded chargers and the only one that will give full rate is when the correct values are applied andthe existing resistors in the charger (usually for the benefit of iPad charging) are removed.
If there is another proven way I would love to know it.
 
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