OK. I know of this 3rd party Arduino boards platform:
It adds a "RaspberryPI B+/2" board to the Arduino IDE's Tools > Board menu and you can then compile and upload Arduino sketches to the Raspberry Pi SBC like it was a regular Arduino board.
The Raspberry Pi 1 B+ is pretty long in the tooth. This might mean that you can pick some up for cheap though. I see that support for the Zero W was added, but they didn't add a new boards menu entry:
Maybe the "RaspberryPI B+/2" board selection actually works for all the supported RPi boards and the name was just never updated to reflect the general nature it gained since the platform's creation.
I see there is also a proposal to add support for the 3B+
but that one has not been merged so you'd need to merge those changes in yourself.