Shopping Cart

The EM-18 RFID module is a popular RFID reader designed to read the unique identification data from RFID tags, commonly used in various identification and access control applications. Here’s a detailed description of the EM-18 RFID module:

1. Overview:

• Purpose:

  • The EM-18 RFID module is used to read RFID tags operating at a frequency of 125 kHz. It is typically used in applications such as access control systems, time and attendance systems, and identification systems.

• Type:

  • It is a passive RFID reader module that can read the data from RFID tags without needing physical contact, operating in the low-frequency (LF) range.

2. Key Components:

• RFID Reader IC:

  • The core component of the EM-18 is its RFID reader IC, which communicates with RFID tags and extracts the unique identification data.

• Antenna:

  • The module includes an integrated antenna or a connector for an external antenna, which is responsible for generating the RF field and receiving signals from the RFID tags.

• Interface Pins:

  • The module features several pins for connecting to a microcontroller or other devices, including power supply, ground, and data output pins.

• Indicator LEDs (Optional):

  • Some EM-18 modules have LEDs to indicate power status or tag detection, providing visual feedback during operation.

3. Working Principle:

• RF Field Generation:

  • The EM-18 generates an RF field through its antenna. When an RFID tag comes within range, it is powered by this field and responds with its unique ID.

• Data Reading:

  • The RFID reader IC receives the signal from the RFID tag and decodes the unique identification number. This data is then sent out through the module’s output pin.

• Output Data:

  • The EM-18 typically outputs the RFID tag’s data in a serial format, which can be read by a microcontroller or computer for further processing.

4. Applications:

• Access Control Systems:

  • Used to read RFID tags in access control systems, granting or denying access based on the tag’s unique ID.

• Time and Attendance Systems:

  • Employed in time and attendance systems to track employee clock-ins and clock-outs.

• Identification and Tracking:

  • Useful in systems that require identification and tracking of objects or individuals, such as inventory management or personal identification.

5. Circuit Connections:

• Power Supply:

  • Connects to a power source typically ranging from 5V to 12V, depending on the module’s design. Ensure proper voltage to avoid damaging the module.

• Data Output:

  • The module provides a serial output (TTL level) that can be connected to the RX pin of a microcontroller or computer for reading the tag data.

• Ground:

  • Connect the GND pin to the ground of the power supply or microcontroller.

• Control Pins (if available):

  • Some modules might have additional pins for control functions, such as enabling or resetting the module.

6. Advantages:

• Simplicity:

  • Easy to use and integrate with microcontrollers or computers, thanks to its simple serial output.

• Low Frequency Operation:

  • Operates at 125 kHz, which is suitable for many RFID applications and typically less prone to interference compared to higher frequencies.

• Cost-Effective:

  • Provides a budget-friendly solution for RFID-based systems, making it accessible for various projects and applications.

7. Limitations:

• Read Range:

  • The effective read range is generally limited compared to higher frequency RFID systems. It depends on the tag and antenna design.

• Limited to LF Tags:

  • The EM-18 reads only low-frequency (125 kHz) tags and does not support higher frequency tags (13.56 MHz or UHF).

8. Example Use Case:

Access Control System:

• In an access control system, the EM-18 RFID reader is installed at the entry point. When an authorized RFID tag (such as a key fob or card) is presented to the reader, the module reads the tag’s ID and sends it to a microcontroller. The microcontroller then verifies the ID and controls access, such as unlocking a door.

Summary:

The EM-18 RFID module is a versatile and easy-to-use tool for reading low-frequency RFID tags. It is well-suited for various applications requiring RFID technology, such as access control and identification systems. Its simple serial interface makes it compatible with many microcontrollers and systems, facilitating straightforward integration and implementation.