Most projectors have a video in and out connector to run both the smaller screen and the projector from the same output, otherwise you can just get a Y cable to split the output 2 ways.

The Allwinner H135 is a 64-bit RISC-V multimedia SoC officially designed for low-cost projectors. However, support for HDMI ...

In most large classrooms, turning the projector on will lower the screen automatically In some large classrooms the screen can be lowered using controls on the touch panel In smaller classrooms, pull ...