7: Arduino sends RFID data to Raspberry Pi

In this tutorial, you are going to build a simple duty recorder.

The mechanism is pretty simple: Arduino sends RFID data to Raspberry Pi 4B. You only need to buy a RFID-RC522 card reader + Raspberry Pi 4B +Arduino uno + jumper wires.

Step 1: Connect the card reader to arduino as follows.

Step 2: The arduino and Raspberry Pi are connected by USB serial port. If you haven't install arduino on Raspberry Pi, type "sudo apt-get update && sudo apt-get install arduino" in the Pi terminal.

Step 3: Check if the RFID library was installed in arduino

Click Sketch >> Include Library. If the RFID library was installed, MFRC522 should be seen.

Otherwise please install the RFID linrary via Sketch >> Include Library >> Manage Libraries. Then search MFRC522

Step 4: Open DumpInfo.ino under Examples >> MFRC522.

Step 5: Open the serial monitor and scan your white RFID card. You should see the UID. Here i hide the UID as xx xx xx xx .

Step 6: Upload the following code to arduino

#include <SPI.h>
#include <MFRC522.h>

#define RST_PIN   9       
#define SS_PIN      10       

MFRC522 mfrc522(SS_PIN, RST_PIN);

void setup()
{
    Serial.begin(9600);
    SPI.begin();   
    mfrc522.PCD_Init(); 
    Serial.println("Duty recorder");
}
void loop()
{
     if ( ! mfrc522.PICC_IsNewCardPresent())
    {
         return;
    }

     if ( ! mfrc522.PICC_ReadCardSerial())
    {
         return;
    }
    String content= "";
    byte letter;
    for (byte i = 0; i < mfrc522.uid.size; i++)
    {
         content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
         content.concat(String(mfrc522.uid.uidByte[i], HEX));
    }
    content.toUpperCase();
    if (content.substring(1) == "xx xx xx xx")  // change the UID of the card to give access
    {
         Serial.println("Staff(Roy WCH) starts to work");
         delay(3000);
    }

    else 
    {
         Serial.println("Access denied");
         delay(3000);
    }
}

Step 7: Write a very simple python code in Raspberry Pi. Then press F5.

You have two cards:

Card A is registered the UID of the staff whose name is called Roy WCH. When card A is put near to the card reader, it shows a message that "Staff (Roy WCH) starts to work".

Card B is not activated and therefore it shows "Access denied"

*The above code are modified from open source platform