One button power control scheme.

Implemented power management for the Atmega328 microcontroller.

When the button is pressed, the microcontroller will receive power and start up. On startup, drives D4 high to maintain power through the transistor.

The microcontroller monitors the time or button presses (on the D2 Int0 line) for shutdown actions.

The tracking of button presses is carried out by the microcontroller along the D2 input line (which is pulled up to power supply) when it goes into a low state.

In the example sketch, connect the button module: GND and Vcc to an external power source.

Output: GND to Arduino GND, Vcc to Arduino Vin, P (power control) to Arduino D13 (or D4), B (button input) to Arduino D2 (Int0).

The complementary pair of AO4606 transistors can be respectively replaced by IRLML6402TRPBF and IRLML0030TRPBF transistors respectively of polarity. AO4606 is a convenient compact case, the IRLML6402TRPBF and IRLML0030TRPBF transistors have better characteristics.

The diode BAV70WT1G can be replaced by two 1N4148WTs.