Originally Posted by kraqh3d
... I know, I know, I know. I really need to purchase a 1.8v TTL serial/usb cable. Why is the one from FTDI so expensive? I've got five PL-2303 based CA-42 cables that I've re-purposed for my other ARM boxes. It's too bad but they are 3.3v.
Any help will be appreciated, and I don't mind working up a detailed procedure from my experiences.
If this works, I'll need to break the Kindle again. Any suggestions on how to do it? I also should probably flash the original kernel back and restore standard 3.3 before breaking it.
You can voltage-shift your 3.3v adapters to 1.8v. You might only need one side of the "super simple level shifter" circuit I posted in its own thread (see the hardware index). On my K5, I only need a single diode and 22K resistor (plus removing a status LED on the 3.3v adapter because the K5 cannot sink enough current to extinguish the LED). The K4 and K5 have series 1K resistors on the serial Rx and Tx lines, so you must take that into account (which is why I use 22K resistor instead of 1K).