I am trying to get an arduino to switch on something on the Raspberry Pi with a Mosfet.

Would this layout work?

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  • What is the MOSFET for? Why not just connect the PI and Arduino grounds and connect an Arduino gpio set as an output to a Pi gpio set as an input (with a resistor divider if it's a 5V Arduino)?
    – joan
    Jun 23, 2015 at 8:00

1 Answer 1


Joan is right. If you are trying to have an output on the Arduino trigger an input on the pi, then you merely need to use 2 resistors and create a voltage divider to change the 5V out of the arduino to 3V. The mosfet is unnecessary.

(Alternatively, if you've got more than one pin to connect you could use a buffer IC like the 74HC4050.)

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