RFID Interfacing with Arduino
Interfacing RFID with Arduino
Uno
In
this tutorial we are going to design a system to read the ID of RFID cards. RFID stands for Radio Frequency Identification. Each card has a unique ID embedded in it. These systems have many applications, like in
offices, shopping malls and in many other places where only the person with
authorization card is allowed to enter in the room. RFID is used in shopping malls to stop a
theft from happening, here the product will be tagged with RFID chip and when a
person leaves a building with the RFID chip an alarm is raised automatically
and so the theft is stopped. The
RFID tag is designed as small as grain of sand. The RFID authentication systems are easy to design
and are cheap in cost. Some schools and colleges
nowadays use RFID as attendance register.
Components Required
Hardware: ARDUINO UNO, power supply (5v),
100uF capacitor , buttons (two
pieces), 1KΩ resistor (two pieces), EM-18(RFID
reader module), LED, JHD_162ALCD (16*2LCD).
Software: arduino IDE (Arduino nightly).
Circuit Diagram and Explanation
In
16x2 LCD there are 16 pins over all if there is a back light, if there is no
back light there will be 14 pins. One
can power or leave the back light pins. Now in the 14 pins there are 8 data pins (7-14 or
D0-D7), 2
power supply pins (1&2 or VSS&VDD or GND&+5v), 3rd pin for contrast control (VEE-controls
how thick the characters should be shown) and 3 control pins (RS&RW&E).
In the
circuit, you can observe that I only took two control pins as his
give the flexibility of better understanding. The contrast bit and READ/WRITE are not often used so they can be shorted to
ground.
This puts LCD in highest
contrast and read mode. We just need to control
ENABLE and RS pins to send characters and data accordingly.
The
connections which are done for LCD are given below:
PIN1
or VSS to ground
PIN2
or VDD or VCC to +5v power
PIN3
or VEE to ground (gives maximum contrast best for a beginner)
PIN4
or RS (Register Selection) to PIN8 of ARDUINO UNO
PIN5
or RW (Read/Write) to ground (puts LCD in read mode eases the communication for user)
PIN6
or E (Enable) to
PIN9 of ARDUINO UNO
PIN11
or D4 to PIN10 of ARDUINO UNO
PIN12
or D5 to PIN11 of ARDUINO UNO
PIN13
or D6 to PIN12 of ARDUINO UNO
PIN14
or D7 to PIN13 of ARDUINO UNO
Before
going to further we need to understand about the serial communication. The RFID module here sends data to the controller
in serial.
It has other mode of
communication but for easy communication we are choosing RS232. The RS232 pin of module is connected to RXD pin of
UNO.
The
data sent by the RFID module goes as:
Now
for setting up a connection between RFID reader and Arduino Uno, we need to
enable the serial communication in UNO. The serial communication enabling in UNO can be done by using a
single command.
1.
Serial.begin(9600);
2.
data = Serial.read();
|
As
shown in figure above, the communication of RFID is done by a BAUD rate of 9600
bits per second.
So for UNO to establish such
baud rate and to start serial communication we use command "Serial.begin(9600);". Here 9600 is the baud rate and is changeable.
Now once data
is received by the UNO, it will be available for taking. This data is picked up by command “data = Serial.read();”. By this command serial data is taken to ‘data’ named
integer.
Once a
card is brought near reader, the reader reads the serial data and sends it to
UNO, the UNO will be programmed to show that value in LCD, so we will have ID
of card on LCD.
You
can understand more about RFID in this tutorial: RFID
based voting machine, RFID
based toll plaza system.
RFID Interfacing with Arduino
Reviewed by XXX
on
สิงหาคม 27, 2560
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