While working on a project that started with an arduino, I ended up having to
make my own PCB for size and power consumption.
I moved to the Atmel
atmega328P which is a pico power microcontroller that is
mostly Arduino compatible.
While digging into the documentation, I realized that the Arduino libraries,
while being really handy, have a few limiting factors (for example changing pins
at the same time) and I started to look on how to code for the avr
microcontroller without the Arduino IDE and libraries.
There are many resources online on how to use the avr CPU with minimal wiring,
but I will concentrate on the toolchain here.