hi I need to power the Udoo x86 plus from the head pins and be able to use and power the wifi and ssd , all from the pins Please help
Why? What is wrong with using the standard 12V connector? I don't believe it is possible to power it through another way.
For an application that I'm working with the barrel connector cannot be used On the header pin there is a Vin pin can this be used?
No, it is an Arduino pin and I even doubt it would work for the Arduino. It definitely is no 12V. Edit: it is 12V.
If you can read electrical schemes, you can download them for the udoo here https://www.udoo.org/docs-x86/Hardware_Reference/Resources.html I still think you cannot power the complete Udoo X86 through the Vin pin on the Arduino side (but I am not an electronic engineer).
The GPIO pin is the same as the barrel connector. It is a smaller diameter pin and may not handle the current.