Arduino Leonardo - Electronic Lock

Placed on 2020-06-22

Fault the code in EEPROM memory

Now we can get a code, check it but what about saving it. Because when you reset the Arduino the RAM is cleared, so we have to find another way of storing it and being able to change it without having to reupload the program. This is where the EEPROM steps in the game ...

So we have to use the EEPROM library.

Storing and Getting the code from EEPROM

#include <EEPROM.h>

unsigned char Eeprom_PasscodeLength = 0;

void GetEepromCode() {
   EEPROM.get(0, Eeprom_PasscodeLength);
   if (Eeprom_PasscodeLength) {
      NewPasscodeLength = Eeprom_PasscodeLength;
      for (unsigned char i = 0; i < Eeprom_PasscodeLength; i++) {
        EEPROM.get(i + 1, Master[i]);
      }
   }
   else {
    NewPasscodeLength = PasscodeLength;
    return;
   }
   PasscodeLength = NewPasscodeLength;
}

void WriteEepromCode(){
  EEPROM.put(0, PasscodeLength);
  for (unsigned char i = 0; i < PasscodeLength; i++) {
    EEPROM.put(i + 1, Master[i]);
  }
}

So now we are able to store and get a code from the EEPROM, it's time to enable it to change the code while the program is still running on the Arduino .

Changing the code while the program is running

void CheckNewCode() {
  if (EnableDebug) {
    Serial.print("dataCountBuff1: ");
    Serial.println(dataCountBuff1);
    Serial.print("dataCountBuff2: ");
    Serial.println(dataCountBuff2);
    Serial.print("codeBuff1: ");
    Serial.println(code_buff1);
    Serial.print("codeBuff2: ");
    Serial.println(code_buff2);
  }  
  if (dataCountBuff1 == dataCountBuff2) {
      if(!strcmp(code_buff1, code_buff2)){
          NewPasscodeLength = dataCountBuff2;
          for (unsigned char i = 0; i <= MaxPasscodeLength; i++) {
            Master[i] = 0;
          }
          
          for (unsigned char i = 0; i <= NewPasscodeLength; i++) {
            Master[i] = code_buff1[i];
          }

          if (EnableDebug) {
            Serial.println();
            Serial.print("Master: ");
            Serial.println(Master);
          }
          lcd.clear();
          lcd.print("Passcodes Match");
          _delay_ms(1000);
          lcd.clear();
        }
     else {
        NewPasscodeLength = PasscodeLength;
        lcd.clear();
        lcd.setCursor(0,0);
        lcd.print("Codes do not match");
        if (EnableDebug) {
          Serial.println();
          Serial.println("Passcodes do not match");
        }
        _delay_ms(1000);
        lcd.clear();
     }
  }
  else {
    NewPasscodeLength = PasscodeLength;
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Codes do not match");
    if (EnableDebug) {
      Serial.println();
      Serial.println("Passcodes are not the same length");
    }
    _delay_ms(1000);
    lcd.clear();
  }
  clearData();
}

void ChangeCode() {
    dataCountBuff1 = 0;
    dataCountBuff2 = 0;
    for (unsigned char i = 0; i <= MaxPasscodeLength; i++) {
      code_buff1[i] = 0;
      code_buff2[i] = 0;
    }
    if (EnableDebug) {
      Serial.println();
      Serial.println("Changing Master");
    }
    lcd.clear();
    lcd.print("Enter new code:");
    lcd.setCursor(0,2);
    lcd.print("press * to confirm");
    Key = WaitForKey();
    while(Key != '*') {
      GetCode();
      Key = WaitForKey();
    }
    Data[data_count] = 0;
    dataCountBuff1 = data_count;
    for (unsigned char i =0; i <= data_count; i++) {
      code_buff1[i] = Data[i];
    }
    clearData();
    lcd.clear();
    _delay_ms(500);
    lcd.print("Confirm new code:");
    lcd.setCursor(0,2);
    lcd.print("press * to confirm");
    Key = WaitForKey();
    while (Key != '*') {
      GetCode();
      Key = WaitForKey();
    }
    Data[data_count] = 0;
    dataCountBuff2 = data_count;
    for (unsigned char i =0; i <= data_count; i++) {
      code_buff2[i] = Data[i];
    }
    clearData();
    CheckNewCode();
    PasscodeLength = NewPasscodeLength;
    if (EnableDebug) {
      Serial.print("PasscodeLength: ");
      Serial.println(PasscodeLength);
    }
    WriteEepromCode();
}

Previous page 8. The code - part 3 - The code Current Page 9. The code - part 4 - More codes Next page 10. The code - part 5 - Setup and Loop 1. Introduction 2. The Schematic 3. The Keypad 4. The LCD module 5. The Servo 6. The code - part 1 - The Keypad 7. The code - part 2 - The LCD 8. The code - part 3 - The code 9. The code - part 4 - More codes 10. The code - part 5 - Setup and Loop 11. The full code Posted by Sander Speetjens

Arduino Leonardo - Electronic Lock

Fault the code in EEPROM memory

Storing and Getting the code from EEPROM

Changing the code while the program is running

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