Quote:
Originally Posted by Linc
I have spent some time today trying to get the Sony ereader PRS-T1 to charge off just a 5V supply without luck. So I put a scope onto the USB data lines and watched the ereader "chatting" to the PC the whole time. So the upshot is that those people at Sony have made damn sure that you can not use any old charger. No combinations of just tying data lones high or low with pullup resistors works, there must be an active "chatting" between the reader and the charger, whcih is why the PC works. I love the Sony reader but I hate the way they have behaved here to make sure you must buy their accessories. It's a dirty way to do business. There is no need for a USB device to "chat" just to charge.
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I read
here (beware: French, search for title: Schéma 003b - Version compatible avec les appareils "difficiles") that data lines must be set to 2V for fussy devices (with separate resistor dividers for D+ and D-, 75kOhms to +5V, 49.9kOhms to the ground).