Hi all, last week I was investigating power supplies on our Udoo board. After googling around I found one very nice web page udoogurus which covers all DC-DC converters on board. Nice reading for all who would like to understand how different supplies are generated. My conclusion was: from UDOO rev. D schematics it is impossible to turn off power supply 5V VCC_SW and 3.3V VDD_SNVS. Step-down converter U26 is enabled when EN pin is high. With its fixed connection to VIN via the resistor it is configured for automatic start-up. Because power good signal drives enable pin for U25 which generates VDD_SNVS this means that first we get stable 5V VCC_SW and little later 3.3V VDD_SNVS. VDD_SNVS drives SAM3X (Arduino) which means it can't be shutdown when i.MX6 is shutdown. The only way is to leave i.MX6 running (pwr_5v_gpio leave low) and just reset SAM3X with sam3x_rst_gpio driving low. I took this second approach and I can run in different modes.
vpeter is right, you can. You can also power it up via dc-in jst white connector behind the ethernet.
