Example Code for Arduino-Fingerprint Matching

Hardware Preparation

• DFRduino UNO R3 (or similar) x 1
• Gravity: Capacitive Fingerprint Scanner/Sensor x1
• Jumper wires

Software Preparation

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

Wiring Diagram

Other Preparation Work

Download and install the library according to the Software Preparation instructions, and ensure the wiring is correct as per the Wiring Diagram.

Sample Code

/*!
 * @file fingerprintMatching.ino
 * @brief Gather fingerprint and compare it with fingerprints in fingerprint library
 * @details Experiment Phenomenon：capture fingerprint image and compare it with all fingerprints in the fingerprint library
                If matched successfully, light up green LED and print ID number. Return 0 when failed.
 * @copyright  Copyright (c) 2010 DFRobot Co.Ltd (http://www.dfrobot.com)
 * @License     The MIT License (MIT)
 * @author [Eddard]([email protected])
 * @version  V1.1
 * @date  2020-03-19
 * @url https://github.com/DFRobot/DFRobot_ID809_I2C
*/
#include <DFRobot_ID809_I2C.h>

DFRobot_ID809_I2C fingerprint;
//String desc;

void setup(){
  /*Init print serial port*/
  Serial.begin(9600);
  /*Take FPSerial as communication serial port of the fingerprint module*/
  fingerprint.begin();
  /*Wait for Serial to open*/
  while(!Serial);
  /*Test whether the device can properly communicate 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);
  }
}

void loop(){
  uint8_t ret = 0;
  /*Set fingerprint LED ring mode, color, and number of blinks
    Can be set as follows:
    Parameter 1:<LEDMode>
    eBreathing   eFastBlink   eKeepsOn    eNormalClose
    eFadeIn      eFadeOut     eSlowBlink   
    Parameter 2:<LEDColor>
    eLEDGreen  eLEDRed      eLEDYellow   eLEDBlue
    eLEDCyan   eLEDMagenta  eLEDWhite
    Parameter 3:<number of blinks> 0 represents blinking all the time
    This parameter will only be valid in mode eBreathing, eFastBlink, eSlowBlink
   */
  fingerprint.ctrlLED(/*LEDMode = */fingerprint.eBreathing, /*LEDColor = */fingerprint.eLEDBlue, /*blinkCount = */0);
  Serial.println("Please press down your finger");
  /*Capture fingerprint image, 10s idle timeout 
    If succeed return 0, otherwise return ERR_ID809
   */
  if((fingerprint.collectionFingerprint(/*timeout=*/10)) != 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");
  }else{
    Serial.println("Capturing fails");
    /*Get error code information*/
    //desc = fingerprint.getErrorDescription();
    //Serial.println(desc);
  }
  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 captured fingerprint with all the fingerprints in the fingerprint library 
    Return fingerprint ID(1-80) if succeed, return 0 when failed 
   */
  ret = fingerprint.search();
  /*Compare the captured fingerprint with a fingerprint of specific ID 
    Return fingerprint ID(1-80) if succeed, return 0 when failed 
   */
  //ret = fingerprint.verify(/*Fingerprint ID = */1);  
  if(ret != 0){
    /*Set fingerprint LED ring to always ON in green */
    fingerprint.ctrlLED(/*LEDMode = */fingerprint.eKeepsOn, /*LEDColor = */fingerprint.eLEDGreen, /*blinkCount = */0);
    Serial.print("Matching succeeds,ID=");
    Serial.println(ret);
  }else{
    /*Set fingerprint LED ring to always ON in red*/
    fingerprint.ctrlLED(/*LEDMode = */fingerprint.eKeepsOn, /*LEDColor = */fingerprint.eLEDRed, /*blinkCount = */0);
    Serial.println("Matching fails");
  }
  Serial.println("-----------------------------");
  delay(1000);
}

Result