Example Code for Arduino-Comparison of fingerprint and template data

Hardware Preparation

• DFRduino Leonardo (or similar) x 1
• Capacitive Fingerprint Sensor - UART (FPC Connector) × 1
• DuPont Wires

Software Preparation

• Arduino IDE
• Download and install the ID809 Library. (About how to install the library?)

Wiring Diagram

Sample Code

Once you press finger down, your fingerprint can be compared with the template data. The template data does not occupy the fingerprint storage capacity, and those for comparison are stored in an array. In this case, the template data can come from external sources (such as SD card and cloud). Please make sure that there are fingerprints stored in ID 1 before using this example.

/*!
 *@file contrastTemplate.ino
 *@brief Extract the ID 1 fingerprint template, and collect fingerprint to compare with it.
 *@copyright   Copyright (c) 2010 DFRobot Co.Ltd (https://www.dfrobot.com)
 *@licence     The MIT License (MIT)
 *@author [fengli]([email protected])
 *@version  V1.0
 *@date  2021-6-01
 *@get from https://www.dfrobot.com
 *@https://github.com/DFRobot/DFRobot_ID809
*/
#include <DFRobot_ID809.h>


uint8_t temp[1008]={0};    //Template data

/*Use software serial when using UNO or NANO*/
#if ((defined ARDUINO_AVR_UNO) || (defined ARDUINO_AVR_NANO))
    #include <SoftwareSerial.h>
    SoftwareSerial Serial1(2, 3);  //RX, TX
    #define FPSerial Serial1
#else
    #define FPSerial Serial1
#endif

DFRobot_ID809 fingerprint;
//String desc;

void setup(){
  /*Initialize serial port for printing*/
  Serial.begin(9600);
  /*Initialize FPSerial*/
  FPSerial.begin(115200);
  /*Use FPSerial as communication serial port of module*/
  fingerprint.begin(FPSerial);
  /*Wait for Serial to open*/
  while(!Serial);
  /*Test whether device can communicate properly with mainboard,
    Return true or false
    */
  while(fingerprint.isConnected() == false){
    Serial.println("Communication with device failed, please check connection");
    /*Get error code information*/
    //desc = fingerprint.getErrorDescription();
    //Serial.println(desc);
    delay(1000);
  }
  //Get the fingerprint template of ID 1
  fingerprint.getTemplate(/*id = */1,temp);
  //Download the template to ID 1
  //fingerprint.downLoadTemplate(/*id = */1,temp);
}

void loop(){
  /*Set the fingerprint LED ring as blue breathing light*/
  fingerprint.ctrlLED(/*LEDMode = */fingerprint.eBreathing, /*LEDColor = */fingerprint.eLEDBlue, /*blinkCount = */0);
  Serial.println("Please press down your finger");
  /*Capture fingerprint image, Disable the collection timeout function
    If succeed return 0, otherwise return ERR_ID809
    Collect fingerprint template data and store them to rambuffer0
   */
  if((fingerprint.collectionFingerprint(/*timeout=*/0,0)) != ERR_ID809){
    /*Set fingerprint LED ring to quick blink in yellow 3 times*/
    fingerprint.ctrlLED(/*LEDMode = */fingerprint.eFastBlink, /*LEDColor = */fingerprint.eLEDYellow, /*blinkCount = */3);
    Serial.println("Capturing succeeds");
    Serial.println("Please release your finger");
    /*Wait for finger to release
      Return 1 when finger is detected, otherwise return 0
     */
    while(fingerprint.detectFinger());
    //Compare the template data with the collected fingerprints
    if(!fingerprint.contrastTemplate(/*TEMP = */temp)){
      /*Set fingerprint LED ring to always ON in green*/
      fingerprint.ctrlLED(/*LEDMode = */fingerprint.eKeepsOn, /*LEDColor = */fingerprint.eLEDGreen, /*blinkCount = */0);
      Serial.println("Matching succeeds, the template matches the finger");
    }else{
      /*Set fingerprint LED ring to always ON in red*/
      fingerprint.ctrlLED(/*LEDMode = */fingerprint.eKeepsOn, /*LEDColor = */fingerprint.eLEDRed, /*blinkCount = */0);
      Serial.println("Matching fails, the template does not match the finger");
    }
  }else{
    Serial.println("Capturing fails");
  }
  Serial.println("-----------------------------");
  delay(1000);
}

Result