I've got one more question before I solder my final bits
I'm using a thumbduino, so the power source is the 5V USB host... I don't have a 9V supply...
Can I run from a regulated 12V supply? Already, I'm going to power the LCD from an external 5V regulator, I'm not sure if the USB host will support the thumbduino and the LCD (I don't think it will negotiate for more than 100mA).
That 9V is connected to both the 33920 and the OBD2 interface, so I don't want to screw that up