ESP8266 and RFID-RC522 module example

In this example we will connect an RFID-RC522 module and connect to a Wemos Mini

The microcontroller and card reader uses SPI for communication . The card reader and the tags communicate using a 13.56MHz electromagnetic field. (ISO 14443A standart tags)

Features:

• MFRC522 chip based board
• Operating frequency: 13.56MHz
• Supply Voltage: 3.3V
• Current: 13-26mA
• Read Range: Approx 3cm with supplied card and fob
• SPI Interface
• Max Data Transfer Rate: 10Mbit / s
• Dimensions: 60mm × 39mm

Datasheet for the chip that used in modules can be found at:

http://www.nxp.com/documents/data_sheet/MFRC522.pdf

Layout

This is how I wired the module to my Wemos Mini as per the documentation

Code

Install the RFID522 library – https://github.com/miguelbalboa/rfid

This is the DumpInfo example modified – its the two pins defined at the top of the code

Source code

#include <SPI.h>
#include <MFRC522.h>
 
#define RST_PIN         D3         // Configurable, see typical pin layout above
#define SS_PIN          D8        // Configurable, see typical pin layout above
 
MFRC522 mfrc522(SS_PIN, RST_PIN);  // Create MFRC522 instance
 
void setup() {
	Serial.begin(9600);		// Initialize serial communications with the PC
	SPI.begin();			// Init SPI bus
	mfrc522.PCD_Init();		// Init MFRC522
	mfrc522.PCD_DumpVersionToSerial();	// Show details of PCD - MFRC522 Card Reader details
	Serial.println(F("Scan PICC to see UID, SAK, type, and data blocks..."));
}
 
void loop() {
	// Look for new cards
	if ( ! mfrc522.PICC_IsNewCardPresent()) {
		return;
	}
 
	// Select one of the cards
	if ( ! mfrc522.PICC_ReadCardSerial()) {
		return;
	}
 
	// Dump debug info about the card; PICC_HaltA() is automatically called
	mfrc522.PICC_DumpToSerial(&(mfrc522.uid));
}

Output

This is the output in the serial monitor

serial monitor info mfrc522

There are many other good examples in the library

I did see errors in the serial monitor windows – wdg reset, I will investigate this

Links

1 set RFID module RC522 Kits S50 13.56 Mhz 6cm With Tags SPI Write & Read for arduino uno 2560