multiple rfid rc522 run the same function/ add/remove card with master card

Hi everyone! i am new in coding for arduino. I need some help with the project i'm working on. my project is a object tracking by using the rfid rc522 for inventory system. so i need to have multi reader in this project. i would like to have 4 reder that will work at the same time. this is how i want my project to work: 1. there is going to be 3 or 4 reader rc522, 1 i2s lec and leds. 2. one rfid tag will be use as the master card. the master card have the ability to add or remove card. 3. when 1 tag is tapped on 1 reader, the card quantity at the reader that it tapped will increase. example when we tap the tag at reader1, reader1 will add 1 card into its memory.

https://github.com/TasmanianDevilYouTube/Arduino/blob/master/RFID_master_slave_cards/RFID_master_slave_cards.ino

this coding is similar but i like to upgrade it to multiple reader. thanks in advance and stay safe!

Ok then, get the supplied example code working with a single reader first. Have you done that?

Jumping straight into trying to add more complexity to something you don’t yet fully understand (or worse hoping someone else will simply do the hard work for you) is no way to learn anything.

hi sir. yes i have tried it. i also tried to modified the coding and run with 2 reader but yet it doesnt work. maybe some help from you guys will really help me with it . thanks you so much

shie1999: hi sir. yes i have tried it. i also tried to modified the coding and run with 2 reader but yet it doesnt work. maybe some help from you guys will really help me with it . thanks you so much

Show us the code then! Explain what is wrong with it in words other than "it doesn't work".

Tip: Read the Forum Sticky which explains how to correctly post code first.