IR Reader reads code funny in two different projects [PLEASE HELP]

thank you for this answer
it helps a lot

wait but to make this work
to comunicate between the two boards
(weather its aTtiny or another arduino)
i will need to use serial right?

how else to comunjcate between them
tx > rx and serial.

Serial.write
and Serial.available ?

and Serial readin
wouldnt work on the fastled project right ?

and the project holding the fastled would need to be the one who can accept some sort of input to know how to turn on / off the led strip

so how could i communicate between the atTiny / another ardino baord
to my main one holding the led fastled
without serial ?