Quote:
Originally Posted by wlaf
Today I went to electroinic store to buy usb-ttl 1.8v convertor, but unfortunately they only had 5-3.3v. What do you suggest? Will it work or I have to create custom board?
Thanks for your help. :-)
8tw, I think hiding kernel messages with the welcome screen is a bad idea. I wish i could work with the boot loader just like what you can do with grub and lilo.
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Several people (including myself) have had success with their kindles seeing 3.3v okay IF the kindle has an additional ground (USB port connected). It seems that the ground pin on the serial connector in some kindle models does not work well.
For the kindle OUTPUT to be seen by the adapter, you may need a series diode, so the kindle can pull the adapter side of the diode to 0.7v (logic zero) or allow the line to float to the 3.3v on the adapter (perhaps pulled up to 3.3v with an additional 20K resistor). If the pullup current is too high (such as when driving a status LED) the kindle may not be able to pull it down to a logic zero.
See the 1.8v level shifter circuit in the hardware index wiki. You probably do not need to use the side of that circuit with the two diodes, which was necessary before using the extra USB ground...