RFID Reader (125Khz) – Serial TTL Hookup Guide
The rhydoLABZ RFID reader reads EM4100 family transponder tags that are brought in proximity to the reader and output the unique tag identification number through serial port @9600 bps.The RFID Card Reader from Rhydolabz is designed specifically for low-frequency (125 kHz) passive tags. Frequency refers to the size of the radio waves used to communicate between the RFID system components. Just as you tune your radio to different frequencies in order to hear different radio stations, RFID tags and readers must be tuned to the same frequency in order to communicate effectively.
The reader output 12 byte including one start, stop byte and 10 unique data byte.The start byte and stop byte are used to easily identify that a correct string has been received from the reader (they correspond to a line feed and carriage return characters, respectively). The middle ten bytes are the actual tag’s unique ID. Vertical and horizontal parity checking has been done in card reading algorithm to ensure data integrity.One status LED is provided to indicate card detection. The normal detection range is 10-15CM for Card Type TAGs.The RFID Reader (as well as the RFID tags sold by rhydoLABZ) uses the EM4102 protocol. Any other tags that also use the EM4102 protocol can be used with the rhydoLABZ RFID reader.
RFID (Radio frequency identification) systems use data strings stored inside RFID tags to uniquely identify people or objects when they are scanned by an RFID reader. These types of systems are found in many applications such as passport protection, animal identification, inventory control systems, secure access control systems, robotics, navigation, inventory tracking, payment systems, and car immobilization.The distance over which the RFID tag is usable is affected by such things as the tag shape and size, materials being used in the area near the reader, and the orientation of the reader and tag in respect to each other and in their operating environment.
Features
- Low-cost method for reading passive RFID EM4100 family transponder tags
- Reading Distance 10-15CM of the reader (Depend card shape)
- 125kHz read frequency
- 9600 baud serial interface
- Enable input allows module to be enabled/disabled externally
- Standard 2.54mm Pitch Bergstrip connector
- Bread Board compatible
- Low power Requirement 5V@ 120mA
- Small Size
- Built in Antenna
- No components at PCB bottom side ( easy to stick to any surface like wood,glass ect.
- Status LED for card detection
- On-Board Power LED
Specification:
PIN Diagram:
RFID Reader (125Khz) – Serial TTL PIN descriptions are as below
Layout:
Led Indication:
- When the module is successfully powered-up, the LED on the reader (PWR) will be ON and the LED on the reader (STS) will blink two times.
- When RFID Reader(125Khz) – TTL detect the RFID tag,the LED on the reader (STS) “blinks” to indicate the presence of passive tag.
Protocol:
All communication is 8 data bits, no parity, 1 stop bit, non-inverted, least significant bit first (8N1). The baud rate is configured for 9600 bps, a standard communication speed supported by any microprocessor or PC, and cannot be changed. The rhydoLABZ RFID Reader Module initiates all communication. The rhydoLABZ RFID Reader Module can connect directly to any TTL-compatible UART or to an RS232-compatible interface by using an external level shifter.When the RFID Card Reader is active and a valid RFID transponder tag is placed within range of the activated reader, the unique ID will be transmitted as a 12-byte printable ASCII string serially to the host.The data format is as shown below:
The start byte and stop byte are used to easily identify that a correct string has been received from the reader (they correspond to a line feed and carriage return characters, respectively). The middle ten bytes are the actual tag’s unique ID.
Example:
Consider a tag with a valid ID of 0A1F4320B0 (10 bytes).
The bytes sent by the reader will be: $0A, $30, $41, $31, $46, $34, $33, $32, $30, $42, $30, $0D
Getting Started :
- Connect RFID reader board as per the circuit diagram given above.
- Connect the power Supply (5V DC) to the power supply input pins.
- When the module is successfully powered-up, the LED on the reader (PWR) will be ON and the LED on the reader (STS) will blink two times. When the module is in an active state and the antenna is transmitting, the LED on the reader (STS) will be blinking.
- The Baud rate supported by the reader is 9600. Make sure the host system is set to the supported baud rate.
How To Test
1. Test your RFID Reader (125Khz) – Serial TTL with PC
- Here a sample test is shown using RhydoLabz USB to Serial Converter (5V/3V3). When USB cable is connected to the converter, “PWR LED”(Blue) on the top of converter module and “PWR LED”(Blue) on the top of RFID Reader (125Khz) – Serial TTL module glows , which shows the power indication.
- The connection details of RFID Reader (125Khz) – Serial TTL with USB to Serial Converter (5V/3V3) and interfacing requirements of RFID Reader (125Khz) – Serial TTL with PC are shown below.
- Many embedded devices communicate over the serial port connection as most modern computers lack a hardware serial port;USB adaptors are used to convert USB data to standard serial port data and viceversa.
- For a quick tutorial on USB to Serial Converter (5V/3V3) and connection details please Go through the link.
- Once you are done with all these procedures , Choose the appropriate COM port that got assigned to the USB in your system by looking into the device manager like as shown below. In this figure you can see USB serial COM3 got selected.
- When RFID Reader (125Khz) – Serial TTL detect the RFID tag,the LED on the reader (STS) “blinks” to indicate the presence of passive tag.
- When PC receives the ID from RFID reader,the data on serial monitor is shown below.
2. Test your RFID Reader (125Khz) – Serial TTL with rhydoLABZ PC Software
- With the help of rhydoLABZ PC software you can see the Tag unique ID in software’s serial monitor window.Here one sample test is shown using RhydoLabz USB to Serial Converter (5V/3V3).
- Install the rhydoLABZ PC Software in your PC shown below.
- Open rhydoLABZ PC software,select appropriate COM port from “Select Comport “ and show the passive RFID tag on reader, you can see the unique id in the PC software’s window as shown below.
3. Test your RFID Reader (125Khz) – Serial TTL with Arduino
- While interfacing RFID Reader (125Khz) – Serial TTL with Arduino, the data from Reader is available at TXD pin of the module which is connected to RXD pin of the Arduino board, connection diagram is shown below.
- sample program is shown below
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/************************************************************************************** Program to read RFID data and print data on serial monitor. BOARD : Arduino Duemilanove **************************************************************************************/ char Rec_Data; // for incoming serial data int start = 0; // indicate end of ID int finish =0; // indicate end of ID int i=0; // data counter char RFID_Data[12]; // RFID ID array void Receive_RFID_Data(); /************************************************************************************** Function : setup() Description : Use it to initialize variables, pin modes, start using libraries, etc. The setup function will only run once, after each power up or reset of the Arduino board. **************************************************************************************/ void setup() { Serial.begin(9600); // opens serial port, sets data rate to 9600 bps } /************************************************************************************ Function : loop() Description : loops consecutively, allowing your program to change and respond. Use it to actively control the Arduino board. ************************************************************************************/ void loop() { Receive_RFID_Data(); if(finish == 1){ // End of id Serial.println(RFID_Data); // Printing ID on serial monitor finish = 0; start = 0; i = 0; } } /************************************************************************************ Function : Receive_RFID_Data() Description : Finding unique ID from RFID Tag ************************************************************************************/ void Receive_RFID_Data() { while(Serial.available()>0){ // checking data available Rec_Data = Serial.read(); if( Rec_Data == 0x0A ) // start byte start = 1; else if(start == 1 && Rec_Data != 0x0D ){ RFID_Data[i]=Rec_Data; // store ID in array i++; } else if(Rec_Data == 0x0D){ // End byte finish = 1; } } } |
- When Arduino board receives RFID data,the data on serial monitor is shown below.
4. Test your RFID Reader (125Khz) – Serial TTL with PIC16F877A
- While interfacing RFID Reader (125Khz) – Serial TTL with PIC16F877A, the data from Reader is available at TXD pin of the module which is connected to RXD pin of thePIC6F877, connection diagram is shown below.
- sample program is shown below
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/****************************************************************************************** Microcontroller -- PIC 16F877 - 40-pin - 8-bit Clock Frequency is 20 MHz -- Period in 200 Nano Seconds USART Baud Rate 9600bps Only the 10 byte RFID data is read The RFID unique tag value is printed on serial monitor *****************************************************************************************/ #include<pic.h> /*************************************************************************************** GLOBAL VARIABLES *******************************************************************************************/ char Rec_Data; // for incoming serial data int start = 0; // indicate end of ID int finish =0; // indicate end of ID int i=0; // data counter char RFID_Data[12]; // RFID ID array /*************************************************************************************** FUNCTION DEFINITIONS ***************************************************************************************/ void UART_String(const char *dat); void UART_Initilization(); void main() { TRISC = 0X80; UART_Initilization(); // uart Initialization GIE = 1; // Globel interrupt enable bit PEIE = 1; // Peripheral interrupt enable bit while(1){ if( finish ){ UART_String(RFID_Data); // printing ID to serial monitor finish = 0; start = 0; i = 0; } } } /*************************************************************************************** Function : interrupt ISR() Description : interrupt service ***************************************************************************************/ void interrupt ISR() { if(RCIF){ RCIF = 0; Rec_Data = RCREG; if( Rec_Data == 0x0A ) // START byte start = 1; else if(start == 1 && Rec_Data != 0x0D){ RFID_Data[i++]=Rec_Data; // store ID in array } else if(Rec_Data == 0x0D){ // Stop byte finish = 1; RFID_Data[i] = '\0'; } } } /*************************************************************************************** Function : USART_Initilization Description : uart basic initilizatin ***************************************************************************************/ void UART_Initilization() { TXEN = 1; SYNC = 0; BRGH = 1; SPBRG = 0X81; SPEN = 1; CREN = 1; RCIE = 1; RCIF = 0; } /*************************************************************************************** Function : USART_String Description : transmiting string of datas ***************************************************************************************/ void UART_String(const char *dat) { while(*dat !='\0'){ TXREG = *dat; while(TRMT!=1); dat++; } } |
- When PIC16F877A receives RFID data,the data on serial monitor is shown below.
Resources:
PC Software
How to Buy:
Click here to buy RFID Reader (125Khz) – Serial TTL
Click here to buy RhydoLabz USB to Serial Converter (5V/3V3).
Click here to buy RFID Tag Card (125kHz)
Support:
Please share your ideas with us, visit our forum for discussion.
Frequently Asked Questions(FAQ):
Q. What type of tag are used to read rhydoLABZ RFID TTL?
Ans.The rhydoLABZ RFID reader reads EM4100 family transponder tags .
Q.Which tag is supported by rhydoLABZ RFID TTL?
Ans. Passive tags.
Q.What is Working voltage of rhydoLABZ RFID TTL.
Ans. Working voltage of rhydoLABZ RFID TTL is 4.5V to 5.5V
Q.Normal detection range of rhydoLABZ RFID TTL reader
Ans. It can detect upto 15cm for card type tag.
Q.what is the Read frequency of rhydoLABZ RFID TTL reader?
Ans. rhydoLABZ RFID TTL reader has 125KHz read frequency.
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