Hello, I'm a programmer but I'm new to electronics.
My project works fine but I need your advice on how to use only one step down to power both, the arduino nano (5v) and the SIM800L (4v) and also I need to know if my connections (resistors, etc.) are acceptable.
Here's a video of my question: Question Video
And here are the schematics of my project:
My project needs to work with 12V, since it will be connected to a house alarm battery.