To all my Arduino brothers. Heres a sooner than later expected update.
I have taken the advice that was given to me . The advice was priceless.
Ok so i have the Uno R3, the mfrc522 rfid module with the card and dongle, a simple bread board, jumper wires, a 9v battery power source and lastly the infamous OLED.
I hooked up the Uno R3 to the RFID card reader and did a successful test run. Then i hooked up the OLED to the unit and also did a seperate test run and as it was a success as well. At this point i attached the solenoid magnetic lock and added it to the rfid code and the lock worked very well with a tweek here and there to the rfid coding. Now all components are hooked up to eachother, but the oled and rfid are working on separate codes.
In order to get the Oled and RFID working on the same library code, i bascically had to write my own sketch from scratch as it was advised on the reply you see above. So i took the RFID sktech i wrote from scratch and the oled sketch i wrote from scratch as well. I then integrated them into one sketch but as you can guess, i had to write and re-write. Then i had to tweek here and fix there. Now i cant explain how i did it all, because this code was my successful accident. All i did was take the advise given to me on this post an to my surprise it all works great.
The only problem i am having is getting the oled to go back to the original screen. For example, I power on the rfid unit. Now i take the dongle and pass it over the rfid reader. The oled the says access granted. But then its stays on that screen. Or if i pass the dongle with the wrong chip in it, it says , access denied and it stays there. in order to get the oled screen to go back to the welcome or original screen i hit the reset button every time.
In short here it is again. I power on the unit. The oled displays the hello or welcome screen setting . Now i pass the dongle over the rfid reader and the oled goes from the welcome/hello screen, to the access granted screen as it is suppose to do. But for some reason it stays there stuck, i cant get it to return to the welcome / hello screen as i want it to.
I dont know if that makes sense but thats the best explanation i can give.
All this again is my successful accident. By taking the advise given on here i was able to make this project a success. I tested the oled and rfid. I then wrote my own codes and tested them repeatedly. Then i painfully integrated them into one code and it was a success.
So my arduino family. I need you once again. I need to get the oled screen to loop or recycle itself to the original screen after it is done displaying a command. I humbly beg your help gentlemen.
I shall await your response , ozzie (iceman69004).