cani i piggyback connections

Hello my arduino family, I just have a question for anyone who can answer it. OK here i go as best i can. Pls Bear with me guys.

I am in the process of building my 3 rfid solenoid locking system. The question is as follows;

Can the rfid and the tft 2.8 module display share the same pinouts and still be able to carry out there separate commands. So if the code is written for the display to do 1 command and the rfid to do its locking command , will it work at the same time? I have combined the LED lites and the buzzer and it seems to work just fine. But again , they are just lites and a buzzer. The solenoid and rfid with uno module are more complicated.

I would have answered the question myself by just doing it, but im trying to save money on buying what i need while saving on what i dont think i may need. Wait did that make sense. ? I think i have described it as best i can guys. I hope i didnt confuse anyone cause i sure confused myself for a minute there

thanx everyone, ozzie

It depends on how they are communicating so we'd need more info. If they are communicating by serial then they probably cannot share. If by SPI then they'd share 3 of the pins but each would need its own SS pin. If by I2C then they can share both pins.

Short answer, need more info on exactly what you are talking about.

In general, though, no, two pins can't be used for two different purposes.