I am beginning a new project. I want to connect 4 Parallax RFID readers to a PIC 16F877.
I have already have the code written for one reader, but now I need to expand to 4. I know I will need to use ports other than only the internal USART.
Does anyone have an idea how I might "scan" the 4 ports, and when an input is found on one of them collect the data?
It seems like I am asking for an interrupt routine, but maybe there is some simpler method using IF, Then statements. Has anyone got an idea?
Thanks
Dan