Help me saving to the EEPROM

nemo4all · August 17, 2011, 2:36pm

I wrote a code to switch on and off two LED on the arduino..and control the brightness of one of those two LEDs..
I am trying to save the current state of the LEDs, so that if the power is switched off and on the LEDs should resume to the last state they were in before the power off..

but sometimes they they are not resuming properly...
I am unable to make out where am I making the mistake.. is it in saving or in reading...??

here is the code below..

#include <IRremote.h>
#include <EEPROM.h>
int pin1 = 3;
int pin2 = 4;
int pin3 = 5;
int RECV_PIN = 11;
int fadered = 5;
int pin1State = LOW;
int pin2State = LOW;
int val;
int state;
int state1;
int btn1_Cnt = LOW;
int btn2_Cnt;

IRrecv irrecv(RECV_PIN);
decode_results results;

void setup()
{
  irrecv.enableIRIn();
  pinMode(pin1, OUTPUT);
  pinMode(pin2, OUTPUT);
  pinMode(pin3, OUTPUT);
  fadered = EEPROM.read(1);

  /********** THIS IS TO READ WHAT WAS THE STATE OF PIN3 SAVED LAST TIME ***********/

  btn2_Cnt = EEPROM.read(2);

  if(btn2_Cnt % 2 == 0)
    analogWrite(pin3, 0);
  else
    analogWrite(pin3, fadered); 


  /********** THIS IS TO READ WHAT WAS THE STATE OF PIN1 SAVED LAST TIME ***********/

  btn2_Cnt = EEPROM.read(0);

  if(btn2_Cnt % 2 == 0)
    digitalWrite(pin1, LOW);
  else
    digitalWrite(pin1, HIGH); 


}
void loop() {
  if (irrecv.decode(&results)) {

    /********** THIS PART IS FOR PIN1 ************/

    if(results.value == 0xffb24d){
      btn1_Cnt++;
      if(btn1_Cnt % 2 == 0)
        digitalWrite(pin1, LOW);
      else
        digitalWrite(pin1, HIGH);

    }

    /********** THIS PART IS FOR PIN3 ************/

    if(results.value == 0xff38c7){
      btn2_Cnt++;
      if(btn2_Cnt % 2 == 0)
        analogWrite(pin3, 0);
      else
        analogWrite(pin3, fadered); 
    }

    if(results.value == 0xff7887 && fadered <=250){
      fadered = fadered + 5;
      analogWrite(pin3, fadered);
    }

    if(results.value == 0xff50af && fadered >=10){
      fadered = fadered - 5;
      analogWrite(pin3, fadered);
    }

    /********** THIS IS FOR SAVING THE BRIGHTNESS VALUE IN EEPROM ************/

    val = fadered;
    if(val != EEPROM.read (1)){
      EEPROM.write(1, val);
    }

    /********** THIS IS TO SAVE THE LAST STATE OF THE PIN3 ************/

    state = btn2_Cnt;
    if(state != EEPROM.read (2)){
      EEPROM.write(2, state);
    }

    /********** THIS IS TO SAVE THE LAST STATE OF THE PIN1 ************/

    state1 = btn1_Cnt;
    if(state1 != EEPROM.read (0)){
      EEPROM.write(0, state1);
    }
    
    
    irrecv.resume(); 
  }
}

system · August 17, 2011, 2:49pm

is it in saving or in reading...??

Debug prints will give you the answer.

JO3RI · August 17, 2011, 2:54pm

Don't know if it helps, but your value to write to EEPROM has to be + and has to be >=0 and <= 255

it might help to use the Serial Monitor to see what values are written before you write them and after you read them.

void setup()
{
    Serial.begin(9600);
}

    val = fadered;
    if(val != EEPROM.read (1)){
      Serial.println(val);
      EEPROM.write(1, val);
    }

system · August 17, 2011, 3:01pm

Well spotted - I missed the "int" declaration.
If you want to write "int"s, look at EEPROMWriteAnything over at the playground.

nemo4all · August 17, 2011, 4:52pm

I wrote the code in this way ...
But it is still reacting the same way....

#include <IRremote.h>
#include <EEPROM.h>
#include "EEPROMAnything.h"
int pin1 = 8;
int pin2 = 4;
int pin3 = 9;
int RECV_PIN = 11;
int fadered = 5;
int pin1State = LOW;
int pin2State = LOW;
int val;
int state;
int state1;
int btn1_Cnt = LOW;
int btn2_Cnt;

IRrecv irrecv(RECV_PIN);
decode_results results;

void setup()
{
  irrecv.enableIRIn();
  pinMode(pin1, OUTPUT);
  pinMode(pin2, OUTPUT);
  pinMode(pin3, OUTPUT);

  
 EEPROM_readAnything(1, fadered);

  /********** THIS IS TO READ WHAT WAS THE STATE OF PIN3 SAVED LAST TIME ***********/



    EEPROM_readAnything(2, btn2_Cnt);

  if(btn2_Cnt % 2 == 0)
    analogWrite(pin3, 0);
  else
    analogWrite(pin3, fadered); 


  /********** THIS IS TO READ WHAT WAS THE STATE OF PIN1 SAVED LAST TIME ***********/


  
  EEPROM_readAnything(0, btn2_Cnt);

  if(btn2_Cnt % 2 == 0){
    digitalWrite(pin1, LOW);}
  else{
    digitalWrite(pin1, HIGH); 
  }

}
void loop() {
  if (irrecv.decode(&results)) {

    /********** THIS PART IS FOR PIN1 ************/

    if(results.value == 0xffb24d){
      btn1_Cnt++;
      if(btn1_Cnt % 2 == 0)
        digitalWrite(pin1, LOW);
      else
        digitalWrite(pin1, HIGH);

    }

    /********** THIS PART IS FOR PIN3 ************/

    if(results.value == 0xff38c7){
      btn2_Cnt++;
      if(btn2_Cnt % 2 == 0)
        analogWrite(pin3, 0);
      else
        analogWrite(pin3, fadered); 
    }

    if(results.value == 0xff7887 && fadered <=250){
      fadered = fadered + 5;
      analogWrite(pin3, fadered);
    }

    if(results.value == 0xff50af && fadered >=10){
      fadered = fadered - 5;
      analogWrite(pin3, fadered);
    }

    /********** THIS IS FOR SAVING THE BRIGHTNESS VALUE IN EEPROM ************/

    val = fadered;
    if(val != EEPROM.read (1)){
 
      EEPROM_writeAnything(1, val);
      
    }

    /********** THIS IS TO SAVE THE LAST STATE OF THE PIN3 ************/

    state = btn2_Cnt;
    if(state != EEPROM.read (2)){
  
      
      EEPROM_writeAnything(2, state);
    }

    /********** THIS IS TO SAVE THE LAST STATE OF THE PIN1 ************/

    state1 = btn1_Cnt;
    if(state1 != EEPROM.read (0)){

      EEPROM_writeAnything(0, state1);
    }
    
    
    irrecv.resume(); 
  }
}

system · August 17, 2011, 6:24pm

But it is still reacting the same way....

That's....not helpful.
What do the debug prints show?

nemo4all · August 17, 2011, 6:36pm

I tried to print the values what I am writing to the EEPROM everytime..

Every time I press the button for Pin1 LED the number 1 is ++, I mean on every press it adds +1...
same for the Pin3 button..

and when I press the buttons for the brightness, the numbers increase/ decrease by 5

Thats all what I get..

IT IS NOT THAT THE WRITE AND READ TO THE EEPROM IS NOT WORKING .. BUT SOMETIMES WHEN I PWR OFF AND ON THE ARDUINO THE LEDs DOES NOT GET BACK TO THE PREVIOUS STATE...THAT IS ONCE IN 4-5 TIMES OF OFF/ON OF ARDUINO..

nemo4all · August 17, 2011, 7:36pm

is it that EEPROM can only save in binary form as 0 or 1...??

if it is so my numbers are more that 1...

system · August 17, 2011, 7:36pm

Stop screaming. You are writing ints to EEPROM, and reading ints from EEPROM, but you are only allowing one byte to hold the two byte int.

Your addresses need to allow for storing ints. The write method actually returns the next available address.

system · August 17, 2011, 7:51pm

PaulS:
Your addresses need to allow for storing ints. The write method actually returns the next available address.

Exactly what I was going to say.

To elaborate, an int takes two bytes to store, if you try to store an int in eeprom address 1, it takes both 1 and 2.
Now if you store one in 2, it takes 2 and 3.
At this point your first int's second half has been run over by the second int, and it comes out wildly different than it went in.

If you space them out (use say, addresses 0, 10, 20, 30, 40 etc.) it should work quite a bit better.

nemo4all · August 18, 2011, 1:59am

Bobnova:

PaulS:
Your addresses need to allow for storing ints. The write method actually returns the next available address.

Exactly what I was going to say.

To elaborate, an int takes two bytes to store, if you try to store an int in eeprom address 1, it takes both 1 and 2.
Now if you store one in 2, it takes 2 and 3.
At this point your first int's second half has been run over by the second int, and it comes out wildly different than it went in.

If you space them out (use say, addresses 0, 10, 20, 30, 40 etc.) it should work quite a bit better.

Thanks Bobnova... now instead of saving in 0, 1, 2 I am saving to 0, 3, 6..It just solved the problem..

system · August 18, 2011, 4:48am

Excellent, that's good to hear.

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