What is wrong with the way I write and or read the EEPROM adresses?

Question

Consider:

#include <EEPROM.h>

byte guifactor1 = 1;
byte guifactor2 = 2;
byte guifactor3 = 3;
byte guifactor4 = 4;
byte guifactorgas = 5;
byte guifactorwater = 6;

volatile unsigned long count1factor;
volatile unsigned long count2factor;
volatile unsigned long count3factor;
volatile unsigned long count4factor;
volatile unsigned long countgasfactor;
volatile unsigned long countwaterfactor;

void loop(){
if (guifactor1 > -1){
    EEPROM.write(1, guifactor1);
    EEPROM.commit();
    count1factor = EEPROM.read(1);
    Serial.println(count1factor);
  }

  if (guifactor2 > -1){
    EEPROM.write(2, guifactor2);
    EEPROM.commit();
    count2factor = EEPROM.read(2);
    Serial.println(count2factor);
  }

  if (guifactor3 > -1){
    EEPROM.write(3, guifactor3);
    EEPROM.commit();
    count3factor = EEPROM.read(3);
    Serial.println(count3factor);
  }

  if (guifactor4 > -1){
    EEPROM.write(4, guifactor4);
    EEPROM.commit();
    count4factor = EEPROM.read(4);
    Serial.println(count4factor);
  }

  if (guifactorgas > -1){
    EEPROM.write(5, guifactorgas);
    EEPROM.commit();
    countgasfactor = EEPROM.read(5);
    Serial.println(countgasfactor);
  }

  if (guifactor1 > -1){
    EEPROM.write(6, guifactorwater);
    EEPROM.commit();
    countwaterfactor = EEPROM.read(6);
    Serial.println(countwaterfactor);
  }
}

void setup(){

}

The problem I have with my code is that it either doesn’t write the value to the EEPROM or it doesn’t read the value as it doesn’t print anything to the monitor.

I expected to read 1 2 3 4 5 6 from the monitor as I write the bytes to the EEPROM and then transfer the value to the unsigned long and print the variable.

Answer 1

You forgot to call Serial.begin() in setup().

As a side note, your if tests are useless. The compiler warns me that:

comparison is always true due to limited range of data type

For reference: the previous answer, valid for the initial question where guifactor1 and co. were all unsigned long.

---

The program does nothing because all the actions are conditioned on tests such as

if (guifactor1 > -1)

and these tests are always false. The reason they are false is because arithmetic comparison operators such as < perform usual arithmetic conversions on their operands prior to doing the actual comparison. Since guifactor1 is unsigned long, and this type has a higher conversion rank than int (the type of -1), the second operand is implicitly converted to unsigned long, yielding ULONG_MAX.