Atmega328p with arduino without the board

Question

Perhaps this is a beginners question and I am not sure. I currently have a custom made circuit with an atmega328p chip connected to an mpu6050. However, when I program in Arduino I am not sure what to do? I can't pick a "board" as the atmega328p doesn't belong to a board? (from what I'm aware at least)

How in Arduino do I choose to program for my atmega328p chip? Without having to pick a board such as Arduino Uno etc. As I don't have any board for this. Or does the atmega328p chip always belong to a certain board?

I have a fully working circuit with a cyrstal (16MHz), battery sources, atmega328p etc. But I don't know how to program it with Arduino? I can program it in C, but would like to use Arduino due to certain libraries.

Answer 1

The board option is actually selecting a variant out of the installed cores (which provide the basic Arduino framework for a group of boards/chips). Each core can support multiple variants/boards/chips and can give each of them individual lists of options. There certainly also is a core, which supports the Atmega328p with all needed config options (like the frequency setting). You just need to install it from the boards manager.

Though, since you use a 16MHz crystal just like the Uno/Nano, you could just select the Uno or Nano as board. Neither the Arduino IDE, nor the Atmega328p can know, that the Atmega is actually a standalone one and not mounted on an Arduino board. So you can just use that board when you keep the config options inherent to an Arduino Uno/Nano (frequency setting and pin mapping mainly).