How to Use EM-18 RFID reader module: Examples, Pinouts, and Specs

The EM-18 RFID Reader Module by Innovations is a compact radio frequency identification (RFID) reader that is capable of reading 125 kHz RFID tags and cards. It is widely used for identification and access control in various applications such as attendance systems, security systems, and personal identification.

• Access control systems
• Asset tracking
• Personal identification
• Attendance systems
• Industrial automation

• Operating Voltage: 4.5V to 5.5V
• Operating Current: 50mA (typical)
• Operating Frequency: 125 kHz
• Read Distance: Up to 10 cm (depending on the tag)
• Interface: Serial TTL
• Baud Rate: 9600 bps

1. Connect the VCC pin to a 5V power supply.
2. Connect the GND pin to the ground of the power supply.
3. Connect the TX pin to the RX pin of a microcontroller like Arduino UNO.
4. The /SEL pin can be connected to ground to enable the module permanently or to a digital pin of the microcontroller to control it programmatically.

• Ensure that the power supply does not exceed 5.5V to prevent damage to the module.
• Place the RFID tags or cards close to the module for optimal reading.
• Use a proper level shifter if connecting to a microcontroller operating at a different logic level than 5V.

#include <SoftwareSerial.h>

SoftwareSerial RFID(10, 11); // RX and TX

void setup() {
  RFID.begin(9600); // Start serial to RFID reader
  Serial.begin(9600); // Start serial to PC
}

void loop() {
  if (RFID.available() > 0) {
    // Read data from the RFID reader
    String code = RFID.readStringUntil('\n');
    
    // Print the RFID code to the Serial Monitor
    Serial.println(code);
  }
}

• RFID Tag Not Detected: Ensure that the tag is within the read range and properly oriented towards the reader.
• Serial Communication Errors: Verify the baud rate and connections between the RFID module and the microcontroller.
• No Power to the Module: Check the power supply connections and voltage levels.

• If the RFID tag is not being read, try moving it around the antenna area to find the spot with the best reception.
• Ensure that the serial connections are secure and that there is no interference from other devices.
• Use a multimeter to check the voltage levels at the VCC and GND pins to ensure they are within the specified range.

• Q: Can the EM-18 module write to RFID tags?

  • A: No, the EM-18 is a read-only module and cannot write to RFID tags.

• Q: What is the maximum read range of the EM-18 module?

  • A: The maximum read range is up to 10 cm, but this can vary depending on the tag and environmental conditions.

• Q: How do I connect multiple EM-18 modules to a single microcontroller?

  • A: You can connect multiple EM-18 modules using different serial ports or by using a multiplexer for the serial lines.

Remember to always refer to the manufacturer's datasheet for the most accurate and detailed information about the EM-18 RFID Reader Module.