WaveShare Finger print Sensor Module ARDUINO Code

waveshare_Finger_Print_Sensor_Test.ino

// Code was tested on Arduino MEGA or Leonardo, I THINK, dont actually remember.
// no warranties or guarantees
// use this as it is.

#include <EEPROM.h>
int address = 0;
byte userID;

int addBtn = 5;
int chkBtn = 6;
int outLed = 13;

#include <SoftwareSerial.h>
SoftwareSerial mySerial(10, 11); // RX, TX

void setup() {
  digitalWrite(addBtn, HIGH);
  digitalWrite(chkBtn, HIGH);
  pinMode(addBtn, INPUT);
  pinMode(chkBtn, INPUT);

  Serial.begin(9600);
  Serial.println("Starting now..!");
  mySerial.begin(19200);
  userID = EEPROM.read(address);

//  delay(1000);
//  byte chkCmd[] = {0xF5, 0x05, 0x00, 0x00, 0x00, 0x00, 0x05, 0xF5};
//  for(int i=0; i<8; i++){
//    mySerial.write(chkCmd[i]);
//  }
//  EEPROM.write(address, 0);
//  userID = EEPROM.read(address);
//  Serial.println("ALL DELETED..!");
  
  pinMode(outLed, OUTPUT);
  digitalWrite(outLed, LOW);
}

void loop() {
  if(digitalRead(addBtn) == LOW){
    delay(500);
    if(digitalRead(addBtn) == LOW){
      while(mySerial.available()>0)mySerial.read();
      Serial.print("Inside ADD..!\n USER ID=");
      userID++;
      Serial.println(userID);
      addFingerPrint();
      EEPROM.write(address, userID);
      while(digitalRead(addBtn) == LOW){};
      delay(500);
      Serial.println("ADDED");
    }
  }
  if(digitalRead(chkBtn) == LOW){
    delay(500);
    if(digitalRead(chkBtn) == LOW){
      while(mySerial.available()>0)mySerial.read();
      Serial.println("Inside CHECK..!");
      int chk = chkFingerPrint();
      if(chk==1){
        digitalWrite(outLed, HIGH);
        delay(2000);
        digitalWrite(outLed, LOW);
      }
      while(digitalRead(chkBtn) == LOW){};
      delay(500);
    }
  }

}

void addFingerPrint(void){
  byte reply[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
  byte addCmd[] = {0xF5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xF5};
  byte checkSum = 0;

  delay(1000);
  for(int i=0; i<8; i++){
    addCmd[i] = 0x00;
  }
  addCmd[0] = 0xF5;
  addCmd[7] = 0xF5;
  addCmd[3] = userID;
  addCmd[4] = 1;
  addCmd[1] = 0x01;
  checkSum = 0;
  for(int i=1; i<6; i++){
    checkSum = checkSum^addCmd[i];
  }
  addCmd[6] = checkSum;
  for(int i=0; i<8; i++){
    mySerial.write(addCmd[i]);
    Serial.print(addCmd[i]);
    Serial.print(' ');
  }
  Serial.println();
  delay(1000);

  for(int i=0; i<8; i++){
    addCmd[i] = 0x00;
  }
  addCmd[0] = 0xF5;
  addCmd[7] = 0xF5;
  addCmd[3] = userID;
  addCmd[4] = 1;
  addCmd[1] = 0x02;
  checkSum = 0;
  for(int i=1; i<6; i++){
    checkSum = checkSum^addCmd[i];
  }
  addCmd[6] = checkSum;
  for(int i=0; i<8; i++){
    mySerial.write(addCmd[i]);
    Serial.print(addCmd[i]);
    Serial.print(' ');
  }
  Serial.println();
 
  delay(1000);

  for(int i=0; i<8; i++){
    addCmd[i] = 0x00;
  }
  addCmd[0] = 0xF5;
  addCmd[7] = 0xF5;
  addCmd[3] = userID;
  addCmd[4] = 1;
  addCmd[1] = 0x03;
  checkSum = 0;
  for(int i=1; i<6; i++){
    checkSum = checkSum^addCmd[i];
  }
  addCmd[6] = checkSum;
  for(int i=0; i<8; i++){
    mySerial.write(addCmd[i]);
    Serial.print(addCmd[i]);
    Serial.print(' ');
  }
  Serial.println();

  byte temp=0;
  while(mySerial.available()>0)
    temp =mySerial.read();  
}

int chkFingerPrint(void){
  byte chkCmd[] = {0xF5, 0x0C, 0x00, 0x00, 0x00, 0x00, 0x0C, 0xF5};
  byte reply[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
  for(int i=0; i<8; i++){
    mySerial.write(chkCmd[i]);
    Serial.print(chkCmd[i]);
    Serial.print(' ');
  }
  Serial.println();
  delay(1000);
  while(mySerial.available()<8){};
  int i=0;
  while(mySerial.available()>0){
    reply[i] = mySerial.read();
    Serial.print(reply[i]);
    Serial.print(' ');
    i++;
  }
  Serial.println();
  if(reply[0]==0xF5 && reply[4]==0x01 && reply[7]==0xF5){
    while(mySerial.available()>0)mySerial.read();
    return(1);
  }
  else{
    while(mySerial.available()>0)mySerial.read();
    return(0);
  }
  return(0);
}

dont remember why I did the EEPROM thing in this code.

for completeness of information, referring to THIS module:
UART Fingerprint Reader, onboard processor STM32F205, commercial fingerprinting algorithm, optical sensor

https://www.waveshare.com/uart-fingerprint-reader.htm

how to use enroll and matching fingerprint in arduino ?