Output 3.3V when setting pin to high

Question

I would like to pass 3.3V and Ground to an component. How can I achieve such a thing?

I for example would like to let a wire get 3.3V when I for example do digitalWrite(pin, HIGH). It is hard for me to explain this, so I created an illustration in the hope of better clarifying it.

Edit: I have an product that I have dismantled. On the PCB, there is a push button. I would like to solder some wires to the place where the button is so it can be controlled with an arduino (probably wemos d1). When plugging a cable in the 3.3v of the arduino and a cable from the ground, when connecting it to the push button it will cause a boot of the dismantled product. This explains why I would like to give power to a component ONLY when a pin is set high, so I can for example boot the product via a website / app eventually.

Answer 1

The normal way is to use a P-channel MOSFET as a "high side" switch.

^{simulate this circuit – Schematic created using CircuitLab}

R1 keeps it switched off under "normal" circumstances. Driving D4 LOW makes M1 turn on and allow power through to the "component".

Make sure that the MOSFET has a threshold voltage of no more than (less than?) -3V (that is, somewhere between 0V and -3V - note: P-channel MOSFETs have their thresholds quoted as a negative voltage).

You could connect R1 to 3.3V instead of 5V, but since the GPIO would have 5V on it when HIGH it would be wasting power while idling - so it's better to pull it to 5V instead.