Arduino for STM32

I've choosed this IC due to the fact that I needed MCO/LSE output. I thought that flash and ram was plenty.
I wanted a cheap IC. I don't need a bluepill or a F4 with float acceleration.

The sketch above is mostly a I2C master slave implementation.
I think that I'll go back to AVR for next revision ...

Hi,
I recently compiled a Atmega328P code to a STM32G0.
I just changed the pins for the new hardware and build.

First try :lol: But then I realised:
https://i.ibb.co/cJd9jgm/immagine.png

Wow, using flash is so different! is it due to all uin8_t variables instead of uint32_t?
This is basically my ...

Hi, I'm designing a new circuit using an STM32 instead of the AVR.
I've had a Nucled dev board for years... I got it like 8 years ago!

That said, I'm interested in designing something simple to start with but I cannot find a good starting point.
I've seen that there are idfferent bootloaders, cores ...