I have a system built with a Raspberry Pi 4 and an Arduino to control its startup, shutdown and reset, I have already started to design a current monitor circuit (discussed here).
But one of the problem of the Raspberry Pi is that it will consumme a lot of current even after shutdown, I would like my Arduino to be able to stop the power going through after it is halted.
I was thinking to use a simple relay on high-side, but they make noise right ? A simple NPN or PNP, or MOSFET transistor may find difficult to deal with the current range (0 to 3A).
What would be the ideal solution ?