Distinguish between "H" "S" "U"

i’m joining a robotic competition that required us to do different actions according to the three words “H” “S” "U"on the wall. Can i put templates of those three words and detect them?
Also, how can i send signal to arduino pro mini if a word is recognized?

If the camera is at a fixed position relative to the letter and the letters are just changing then template matching will work.

As for sending a signal, just use an I/O pin on the camera and make that go high. One pin per letter.