EM-18 RFID Reader Module 125 KHz
EM-18 RFID Reader Module 125 KHz, is one of the commonly used modules for Radio Frequency Identification Projects. It can be directly interfaced with a microcontroller using UART communication and with a PC using an RS232 converter. This module can work with any 125KHz RFID tags and it can provide UART / Wiegand26 output formats. The Pitch of output pins are 2.54mm, thus it can be directly inserted into a breadboard for project development.
Features/Specs of EM-18 RFID Reader Module 125 KHz
- Supply Voltage: +4.5V to +5.5V
- Operating Frequency: 125KHz
- Read Distance : 10cm
- Current Rating : < 50mA
- Communication parameter:9600bps
- Reading distance: 10cm, depending on TAG
How to Use EM-18 RFID Module
EM-18 is used like any other sensor module. First, we choose the mode of communication between EM-18 MODULE and CONTROLLER. Next, we will program the controller to receive data from the module to display. Next power the system. When a tag is brought near the MODULE it reads the ID and sends the information to the controller. The controller receives the information and performs action programmed by us.
Step1: Establishing a mode of communication. EM-18 can provide output through two communication interfaces. One is RS232 and another is WEIGAND. The form of communication is selected by SEL pin. If the SEL pin is selected HIGH then the form of communication is RS232 and if the SEL pin is pulled LOW then the form of communication is WEIGAND. Usually, the RS232 is selected because it’s popular so the SEL pin is pulled HIGH.
Step2: The output of the EM-18 MODULE bit rate is 9600bps (bit per second). The controller should be programmed to receive information from MODULE at this rate. If the bit rate of the controller mismatches then the system will not work correctly.
Now let us consider a simple EM-18 circuit diagram,
In the circuit, BUZZER is not compulsory. When a TAG is read the BUZZER turns ON. As given in circuit, TX is given to CONTROLLER which is to receive DATA.
Consider a TAG is brought near the EM-18 MODULE. The EM-18 MODULE reads the ID and sends the information to the controller in 12 ASCII CHARACTERS. In them, 10CHARACTERS represent the TAG ID and 2 CHARACTERS are XOR of the previous 10 CHARACTERS.
So DATA sent = 10ASCII DATA (tag no.) + 2ASCII DATA (XOR result)
Once the information is sent, the EM-18 MODULES stop sending DATA. This serial DATA received by the controller through RX pin contains TAG information which is ready for processing. We can program the controller to save the DATA or process it to provide a response immediately.
Note: Product Images are shown for illustrative purposes only and may differ from the actual product