I'm trying to understand how the schematic from this github repo works. It uses an RTC to turn on an arduino, via a npn transistor and a mosfet.
I'm novice with electronics, so this might be a simple circuit. Specifically, I don't understand the combination of the npn and the mosfet. I get that the RTC pin is turning on the npn transistor to allow current to flow, and that somehow that connects the arduino to ground, but I don't get how the grounding part works.
- how does connecting the mosfet drain to arduino ground permit current to flow?
- how is current flowing back from arduino ground to vcc ground?
- what is the role of the capacitors?
- why is the npn emitter connected to mosfet collector?
I'm sure I have some basic misconceptions, hopefully the above is enough for y'all to help me identify them?
Also, if y'all can help me identify the names of patterns used in this circuit, it'd help me.
Also, ps, what tools might I use to simulate circuits like this one and learn on my own how/what/why? I'm aware of sparkfun's tutorials and some courses on udemy, but what are other go-tos?
Edit: related, Using a DS3231 RTC alarm + MOSFETS to turn on a MCU