Cottonwood: UHF Long distance RFID reader module

Introduction

Long Range UHF RFID Reader is an important way to read information and input information. Automatic identification technology has been developed in recent years. Now it is a new high technology which includes barcode technology, magnetic strip (card) technology, RF technology, optical character recognition technology, and biological recognition, distance Card Reader and etc.

In normal case, UHF RFID tags need less power than the reader which needs to have high receiving sensitivity. In certain system, the transmit path and receive path are independent of each other in the reader, especially when the uplink and downlink have different frequency.

Technically, different applications can choose different transmit power. However, there are regulations that need to be met. Usually the RF power 100mW~500mW is suitable for all kinds of RFID distance reader system. In different regions and areas, the reader has to follow different regulations.

Cottonwood distance reader has many advantages such as: compatibility with different protocols, high reading speed multi-tags reading, linearly polarized antenna, waterproof appearance designing and etc. It can be widely used in RFID systems, and is very friendly to further development based on it.

model:RFID_UHF_TTL_CW

model:RFID_UHF_USB_CW

Application Ideas

Long Range UHF RFID Reader is an important way to read information and input information. Automatic identification technology has been developed in recent years. Now it is a new high technology which includes barcode technology, magnetic strip (card) technology, RF technology, optical character recognition technology, and biological recognition, distance Card Reader and etc.

In normal case, UHF RFID tags need less power than the reader which needs to have high receiving sensitivity. In certain system, the transmit path and receive path are independent of each other in the reader, especially when the uplink and downlink have different frequency.

Technically, different applications can choose different transmit power. However, there are regulations that need to be met. Usually the RF power 100mW~500mW is suitable for all kinds of RFID distance reader system. In different regions and areas, the reader has to follow different regulations.

Cottonwood distance reader has many advantages such as: compatibility with different protocols, high reading speed multi-tags reading, linearly polarized antenna, waterproof appearance designing and etc. It can be widely used in RFID systems, and is very friendly to further development based on it.

Schematic

• Schematic

Usage

Hardware Installation

Programming

• Arduino sample code for Xbee UHF RFID Reader Tutorial (Arduino issues scan commands)

<syntaxhighlight lang="c">

/*

 The circuit:
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
* 10K resistor:
* ends to +5V and ground
* wiper to LCD VO pin (pin 3)

• /

// include the library code:

1. include <LiquidCrystal.h>
2. define BUFFSIZ 90

//RFID parser char buffer_RFID[BUFFSIZ]; char buffidx_RFID; char response_str[64];

char command_scantag[]={0x31,0x03,0x01};//const

unsigned char incomingByte;

unsigned char parsed_okay=0;

unsigned char tag_found_number;

unsigned int bytecount=0;

// initialize the library with the numbers of the interface pins LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup(){

 parsed_okay=0;
 
 // set up the LCD's number of columns and rows: 
 lcd.begin(16, 2);
 // Print a message to the LCD.
 lcd.print("Xbee UHFRFID Reader");
 
 Serial.begin(9600);
 Serial1.begin(115200);

 Serial.println("Test Xbee Connection");
 

}

void loop() {

 while(Serial.available())
 {
   incomingByte = Serial.read();
  
   if(incomingByte='r') {
     Serial1.print(command_scantag);
     parsed_okay=0;
   }
 }

 while(Serial1.available())
 {
   incomingByte = Serial1.read();
   Serial.print(incomingByte);
   
   if(incomingByte==0x32 && parsed_okay==0) {
     bytecount=0;
     parsed_okay=1;
   }
   
   bytecount++;
   
   if(bytecount==3) {
      lcd.clear();    
      lcd.print(incomingByte, DEC);
   }
   
   
 }
 

}

</syntaxhighlight>

• Arduino sample code for Xbee UHF RFID Reader Tutorial (GUI Part)

<syntaxhighlight lang="c">

/*

 The circuit:
* LCD RS pin to digital pin 12
* LCD Enable pin to digital pin 11
* LCD D4 pin to digital pin 5
* LCD D5 pin to digital pin 4
* LCD D6 pin to digital pin 3
* LCD D7 pin to digital pin 2
* LCD R/W pin to ground
* 10K resistor:
* ends to +5V and ground
* wiper to LCD VO pin (pin 3)

• /

// include the library code:

1. include <LiquidCrystal.h>
2. define BUFFSIZ 90

//RFID parser char buffer_RFID[BUFFSIZ]; char buffidx_RFID; char response_str[64];

char command_scantag[]={0x31,0x03,0x01};//const

unsigned char incomingByte;

unsigned char parsed_okay=0;

unsigned char tag_found_number;

unsigned int bytecount=0;

// initialize the library with the numbers of the interface pins LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup(){

 parsed_okay=0;
 
 // set up the LCD's number of columns and rows: 
 lcd.begin(16, 2);
 // Print a message to the LCD.
 lcd.print("Xbee UHFRFID Reader");
 
 Serial.begin(9600);
 Serial1.begin(115200);

}

void loop() {

 while(Serial.available())
 {
   incomingByte = Serial.read();
  
   Serial1.print(incomingByte);
 }

 while(Serial1.available())
 {
   incomingByte = Serial1.read();
   Serial.print(incomingByte);
   
 }
 

} </syntaxhighlight>

FAQ

Please list your question here:

• I was wondering if it comes with an antenna, or do I need to purchase one separately? Do you have any suggestions on where I can get one, or is it easy to build my own? I am trying to get up to 2-3 m reading.
  • No. It doesn't come with an antenna. There are three options for the antenna:
    • Starter antenna. This antenna can work up to 1 meters. You can order 1 meter antenna.
    • An antenna can work up to 3 meters. You can order here.
    • An antenna can work up to 5 meters. You can order here.
• I was wondering if this reader supports adjustable power levels over UART commands?
  • No. It doesn't.

Support

If you have questions or other better design ideas, you can go to our forum to discuss or creat a ticket for your issue at linksprite support.

Resources

• Quick Start Guide
• Arduino Passthrough Sample Code
• Spruce Sample Project file for Cottonwood
• LinkSprite Recylcing Truck Application,Recycling Truck System Design File
• DataSheet
• UHF RFID reader UART Protocol
• UHF RFID Reader Demo Program for Windows XP
• UHF RFID Reader Demo Program for Windows 7
• rfid_usb program
• UHF RFID Reader demo program with output power adjustable
• PC SDK for TTL Uart/USB UHF RFID reader Module Demo GUI
• STM32 cortex sample code
• Arduino Tutorial of Using UART UHF RFID Reader Module
• Tutorial of Ethernet Based UHF RFID Reader
• cottonwood_arduino.rar

See Also

Other related products and resources.

Licensing

This documentation is licensed under the Creative Commons Attribution-ShareAlike License 3.0 Source code and libraries are licensed under GPL/LGPL, see source code files for details.