RFID IDENTIFIER ON 3 DIFFERENT ARDUINO-SparkFun

Hi, I am working on a project where I am using 3 different RedBoards and SparkFuns connected to 3 different RPis (microcontrollers) that are being sent to another RPi, main RPi, to read in all the information. I’m having an issue because in my project, I am doing data transfer to the main RPi to get the amount of times an rfid was scanned in 3 different locations (store, atrium, and bay). If the carts aren’t in the store or in the atrium, we know they are outside, yet if they aren’t accounted for in the bays, I need an alert to be triggered after 10 minutes. I’m confused on how to read in the different RFID tags from all the different locations (especially since they are on different devices) as well as how to account for the ones outside (not in the bay) and set a timer that’ll trigger a notification when it doesn’t enter the bay. I want to do this on the Arduino IDE; I believe that’s my only option unless there’s another software available for this case.

Note: I am a beginner. Please feel free to include tutorials. All help will be greatly appreciated!

Hello rand33.

What are 'RedBoards and SparkFuns'? That means nothing.

3 different RPis

This is not a Raspberry Pi forum.

Please read the forum instructions that you were re-directed to before you posted.

Thank you.