Micro-FTX
As shipped, unless otherwise requested, is configured for 5v0 i/o levels.
(Attach-1: ftx-bottom)
FTX Jumpers
Since the Kindle uses 1v8 for its serial port, and other controls, the jumpers have to be changed to configuration #3.
(Attach-2: ftx-jmpr)
FTX I/O References
A usable (very quiet) ground and a 1v8 reference for the FTX can be found at the top right of the KT2 board.
(Attach-3: adptr-io-ref)
Serial Port
The "Serial Debug" pad site is wired to the FTX (only Rx and Tx) in the usual manner.
(Attach-4: serial-port)
Hardware Reset (reboot)
This control lead is pulled up to 1v8 and protected from noise by the adjacent resistor, capacitor, and diode combination.
Either pad on the cntrl lead could be used, but to spare some possible grief the pad furthest from existing parts will be used.
(Attach-5: reset-cntrl)
Power on/off
This control lead is pulled up to 1v8 and protected from noise by the adjacent resistor, capacitor, and diode combination.
Either pad on the cntrl lead could be used, but to spare some possible grief the pad furthest from existing parts will be used.
(Attach-6: power-cntrl)
USB Boot
This control pair require a more sophisticated handling than a simple connect to ground (like the two controls above do).
Also, these control leads from the SoC are driven by one of the 3v3 supply rails.
The result of those two facts will require a few parts to interface the boot-mode leads to the FTX bit controls.
FTX CB Leads
These leads will have to be re-configured from the factory default by re-programming the chip's on-board eeprom.
But the Micro-FTX board supplies 4 such control bits and we need only 3 of them.
The re-programming of the Micro-FTX will be the next step in taking control of the KT2. Ah, which is the reason I did not indicate which of CB0 ... CB3 will be used on the pics. ('cause I don't know yet
)
PS:
Yes, the power on/off and the reboot (hardware reset) have been confirmed to be working as expected.