![schematic](https://i.stack.imgur.com/4acEI.png)

[simulate this circuit](/plugins/schematics?image=http%3a%2f%2fi.stack.imgur.com%2f4acEI.png) – Schematic created using [CircuitLab](https://www.circuitlab.com/)

I did add the NPN 2N3904 because I want to put on sleep the Arduino. So I need to put LOW the GPIO when goes in sleep.

This is a prototype. I will port on an Arduino Mini 3V3.

I did forget the pullup from gate, but cannot edit the schema :(

Load is 5V display, with MAX current usage of 67mA. So per OHM Law, I got ~75 Ohm.

Arduino is 5V and his GPIO drive ON/OFF the 2N3904.

I did study that it is common to assume that base current is 1/10 of the collector current. But, what the collector current in my case? That 67mA?

If yes, I need to select a resistor for

5V (Arduino) - 0.9 (Vbe per datasheet) = 4.1/ (0.067 /10 ) = ~600 ohm?

For R2, Do I need to do same absumption?