Ok, I've had enough with my N7 tablet running all sorts of various ROM's and such.. So I picked up a Toshiba WT8 tablet.. Obviously there is no custom ROM to enable OTG charging capabilities.. so I'm kind of stuck with how to handle the power issue.
The WT8 battery should be able to power the tablet during my commuting, and during SQ shows I attend as long as it's charged each night or every other.. So here's my options:
-Remove the battery and use a DC-DC converter to power the tablet directly, and use my existing Arduino/Mosfet delay module I created to control the show by enabling power to the tablet, then 'pressing' the power button to turn it on, and on shutdown it will 'press' the power button to initiate shutdown and then power off the DC-DC.
-Leave the battery and use my existing Arduino/Mosfet delay module to short the USB host pin to ground, power-on the tablet by 'pressing' the power button, then use the tablet on battery.. Then on shutdown 'press' the power button to initiate shutdown, then break the USB host pin and enable a DC-DC 5v supply to feed tablet to charge. My Arduino is powered on at all times in the car so I could even have it charge for a 2hr period overnight and then shutdown the DC-DC?
As far as DC-DC to replace the battery goes... would you just probe the battery connector for voltage while on AC power and try to closely match that voltage for the new dc-dc operating voltage?