zachariasfrings[: > <@zachariasfrings:matrix.org> Sorry yes. 16 columns 2 rows it is. I am also using the rp-pico hal. Does ist already implement this driver or do I need to add it to my project?
> I just started using rust for embedded stuff so this is all quite new to me

the hal will not include drivers for external hardware, no.
you'll need to include a library crate like https://crates.io/crates/hd44780-driver (that's the most popular recent crate as shown in the crates.io search i shared).
if you look at that page, you'll see that it supports both the parallel mode and i2c mode for that display.