Exception 3 on ESP8266 code

Projects Programming
1

Hello! I keep getting an exception(3) on this code. I tried all i finded but i didn't find a solution! Here is the important code

if(getFingerprintEnroll() == true){
      if(downloadFingerprintTemplate(id) == true){
        fbdo.clear();
        for (int i = 0; i < size; ++i){
          String PR2 = GetOldFinger(i);
          Serial.println("\n");
          // FHex is a global variable. 
          Serial.println(FHex);
          delay(200);
          Serial.println("\n");
          Serial.println(PR2);
          delay(200);
          //Prints both variables to see if they have the data. This part is succesfull
          bool res = Compare(FHex, PR2);
          if (res == true){
            
            break;
          } 
          
        }
      }
      }

Here is where the exception occurs. Its inside the Compare fuction

bool Compare (String New, String Old){
    //transforms the Strings to std strings
    std::string a = New.c_str();  //here the exception occurs
    std::string b = Old.c_str();
    double incmn = 0;
    double vSz = 0;
    
    if(a == b) {
        Serial.println(F("100% Similarity!"));
    } else{
        if(a > b) {
             vSz = b.size();
        }else {
             vSz = a.size();
        }
        for(double i = 0; i < vSz;++i){
            if(a[i] == b[i]){
                ++incmn;
                }
        }
    double result = (incmn/vSz)*100;
    Serial.println("\n");
    Serial.println(result);

     if (result > 55) {
      return true;
    } 
  }
  return false;
}

This is what the ESPExceptionDecoder tells me

Exception 3: LoadStoreError: Processor internal physical address or data error during load or store
PC: 0x40205bf4
EXCVADDR: 0x40000000

Decoding stack results
0x4021d919: String::copy(char const*, unsigned int) at C:\Users\Usuario\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266/WString.h line 343
0x40205d8b: loop() at D:\Raúl Gonzalez ASIX 2\Firebase_client/Firebase_client.ino line 151
0x40220208: uart_tx_free(uart_t*) at C:\Users\Usuario\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\uart.cpp line 557
0x4021cc84: Print::println(int, int) at C:\Users\Usuario\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\Print.cpp line 238
0x40100631: cont_check(cont_t*) at C:\Users\Usuario\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.1.2\cores\esp8266\cont_util.cpp line 50

If anyone can help i will be very gratefull! This is for my final proyect that i am doing for my high grade so its very important. If you need anything more tell me.

2

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.