I am currently working on a Pyboard, with an STM32 chip offering UART. It does not mention any protocols, interfaces nor voltage levels in the datasheet. Since it works (i've tried it), but hasn't been specified any particular implemented protocol, i figured UART kind of has its own "default" protocol? Or does it use a specific protocol that is not mentioned?Ummm... no.
That part is true.
A UART is the physical piece of hardware that handles the sending and receiving of the serial data. It can either be on a chip by itself, such as a 16650 or 8250 or numerous others, or implemented as an on-chip peripheral on a microcontroller chip. But a UART is not a communication protocol; it implements one.
RS-232 is a physical interface specification that ensures devices can be interconnected and successfully send and receive signals, without letting out any of the Magic Smoke.
Appreciate any answers