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8 posts

Wannabe Geek


Topic # 27598 31-Oct-2008 23:14
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I am looking for a car charger for my open moko.  Thinking a usb one, like http://www.trademe.co.nz/Browse/Listing.aspx?id=184541331

but not sure, as the seller probally does not know if it would have the correct resistor between the ID pin and GRN to indicate to the neo that it can chage at 1000mAh

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BDFL - Memuneh
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  Reply # 175031 1-Nov-2008 09:31
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I thought all USB chargers spill out the same - it's a USB standard?

I have a few around here, even a white one that was sent to me by Telecom NZ with one of the Okta Touch devices. If you want it PM your name and address and I post to you.






8 posts

Wannabe Geek


  Reply # 175038 1-Nov-2008 10:04
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Yes, USB is a standard, but the standard specifies that devices can only draw 100mA unless they negociate with the bus.  If they successfully negociate with the bus, they standard allows them to draw 500mA.  However, usb charger devices usually short the D+ and D- pins together which indicates to the device they are allowed to draw 1000mA. The open moko relies on a 47K resister between grnd and the ID pin to acheive the same thing.

So, it seems like it might require me to do some testing of devices to see how they are setup.

Can the one you have be opened up and modified?

Glen

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