I like to control the display of the Pimoroni Explorer with a program written in the Arduino IDE (based on C++). With this IDE 2 and adding in Preferences a board manager from ephilhower (Github) as a package_rp2040_index.json then I have made it possible to blink the on-board LED, reading out the on-board temperature sensor as well as an external BME280 temperature/humidity sensor.
Now I like to know which libraries I need to control this display (maybe display.h?).
Is such documentation available to write some code in the Arduino IDE 2?
No, the display on the PIM550 (old version of explorer) is 240x240. I think it is still a ST7789, so the standard ST7789 driver of Arduino should work.
You are even better off with the old explorer: the newer explorer does not use SPI to connect to the display, so the normal Arduino ST7789 drivers won’t work.