Problem facing in EEPROM Reading with Arduino UNO

sreekanthmp · January 22, 2020, 2:00pm

Hi,

I have 2 arduinos which change data using I2C connection between one master and one slave arduino. Actually the master measure a engine working hours and send it to the slave and same has been displayed on OLED display which is connected to Slave arduino. Its working perfectly.

When event occurred slave will write the current hour and minute in Slave'S EEPROM.its also working fine.

when i reading this value,this showing on serial monitor like this 000135.I want to put "." decimal mark between hour and Minutes. {1.35}.

Another problem is that when i switch off and on the SLAVE arduino .Serial monitor shows zero reading.

Can someone explain me, how its possible?

MASTER CODE:

#include <EEPROM.h>
#include <Wire.h>

//#include <Wire.h>/////
#include "RTClib.h"///////////////////// rtc
RTC_DS3231 rtc;////////////////////////// rtc








#define PRESSED LOW
#define NOT_PRESSED HIGH

const unsigned long shortPress = 500;
const unsigned long  longPress = 5000;
typedef struct Buttons {
    const byte pin = 5;
    const int debounce = 10;
 
    unsigned long counter=0;
    bool prevState = NOT_PRESSED;
    bool currentState;
} Button;
Button button;






const uint8_t Toggle = 23;
const uint8_t maint = 3;
const uint8_t EngineCommand = 8;

float value1;
float diffrRead = 0.0;
float Mvalue2;
float Mval;

unsigned long time_now = 0;
boolean already = false;




int EventState = 0;

int addr_secnd = 0;
int addr_Minute = 2;
int addr_hrs1 = 3;
int addr_hrs2 = 4;
int addr_hrs3 = 5;
int addr_hrs4 = 6;
int addr_hrs5 = 7;

int addr_hrs7 = 8;
int addr_hrs8 = 9;
int addr_hrs9 = 10;
int addr_hrs10 = 11;

int secnd = 0;
int Minute = 0;
int hrs1 = 0;
int hrs2 = 0;
int hrs3 = 0;
int hrs4 = 0;
int hrs5 = 0;
int value_secnd;
int value_Minute;
int value_hrs1;
int value_hrs2;
int value_hrs3;
int value_hrs4;

int x6;
int x7;
int x8;
int x9;
int x10;
byte ok;

int period = 100;
unsigned long previousMillis = 0;
unsigned long currentMillis;
unsigned long EngoilPresdelay =0;//millis();
unsigned long Engoildelay=15000;

long lastTime = 0;
long seconds = EEPROM.read(addr_secnd);
long minutes = EEPROM.read(addr_Minute);
long hours = EEPROM.read(addr_hrs2);
long hours1= EEPROM.read(addr_hrs7);
long hours2= EEPROM.read(addr_hrs8);
long hours3= EEPROM.read(addr_hrs9);
bool button_State = false;//////////////////////////sd card
int TempState = 0;
int TempState1 = 0;
int TempState2 = 0;
int TempState3 = 0;
int TempState4 = 0;
int smsState = 0 ;
int smsState1 = 0 ;
int smsState2 = 0 ;
int oldsta=0;
void setup()
{
  
  Serial.begin(9600);
  Wire.begin();
   
  pinMode(EngineCommand, INPUT);
  pinMode(maint, INPUT);
 // pinMode(lastmaint, INPUT);
  pinMode(Toggle, INPUT_PULLUP);
  pinMode(button.pin, INPUT_PULLUP);
  //oled1.clearDisplay();
  //oled1.display();

    
}


void loop() {
 unsigned long startTimehmr = millis();
 
  
  currentMillis = millis();
 if (currentMillis - previousMillis >= period )
 {

    previousMillis += period;

    if (digitalRead(EngineCommand) == LOW)
    {
      EventState = 0;
      if (millis() - lastTime > 0)
      {
        seconds++;
        lastTime = millis();
      }
      if (seconds >59)
      {

         minutes++;
        seconds = 0;

      }
     
      if (minutes > 59)
      {

        hours++;
        minutes = 0;
      }
      if (hours > 9)
      {

        hours1++;
        hours = 0;
      }
      if (hours1 > 9)
      {

        hours2++;
        hours1 = 0;
      }
      if (hours2 > 9)
      {

        hours3++;
        hours2 = 0;
      }
      byte myTime[6];
      myTime[0] =(hours3);
  myTime[1] = (hours2);
  myTime[2] = (hours1);
  myTime[3] = (hours);
  myTime[4] = (minutes);
  myTime[5] = (seconds);
    Wire.beginTransmission( 4 );                  // transmit to device #4
  Wire.write (myTime, sizeof(myTime));            // send data in natural binary to slave
  Wire.endTransmission();      
      
      /*Serial.print(hours3);
      Serial.print(":");
      Serial.print(hours2);
      Serial.print(":");
      Serial.print(hours1);
      Serial.print(":");
      Serial.print(hours);
      Serial.print(":");
      Serial.print(minutes);
      Serial.print(".");
      Serial.println(seconds);
      */
}

}

  if (digitalRead(EngineCommand) == HIGH)
  {
    if (EventState < 1)
    {
      EEPROM.update(addr_secnd, seconds);
      //EEPROM.update(addr_secnd1, seconds1);
      EEPROM.update(addr_Minute, minutes);
      EEPROM.update(addr_hrs2, hours);
      EEPROM.update(addr_hrs7, hours1);
      EEPROM.update(addr_hrs8, hours2);
      EEPROM.update(addr_hrs9, hours3);
      EventState++;
      }
  /*byte myTime[6];
  //myTime[0] = EEPROM.read(addr_hrs6);
 // myTime[1] = EEPROM.read(addr_hrs5);
  myTime[0] = EEPROM.read(addr_hrs9);
  myTime[1] = EEPROM.read(addr_hrs8);
  myTime[2] = EEPROM.read(addr_hrs7);
  myTime[3] = EEPROM.read(addr_hrs2);
  myTime[4] = EEPROM.read(addr_Minute);
  myTime[5] = EEPROM.read(addr_secnd);
  /*  Serial.print(EEPROM.read(addr_hrs9));
      Serial.print(EEPROM.read(addr_hrs8));
      Serial.print(EEPROM.read(addr_hrs7));
      Serial.print(EEPROM.read(addr_hrs2));
      Serial.print(EEPROM.read(addr_Minute));
      Serial.println(EEPROM.read(addr_secnd));*/
 
      
     
      
  }
}

SLAVE CODE

#include <EEPROM.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

//#define VCCSTATE SH1106_SWITCHCAPVCC
#define WIDTH     128
#define HEIGHT     64
#define NUM_PAGE    8
#define NUMFLAKES 10
#define XPOS 0
#define YPOS 1
#define DELTAY 2
#define LOGO16_GLCD_HEIGHT 16
#define LOGO16_GLCD_WIDTH  16

const byte slaveAddress1 = 4;
byte buf[7] = {}; //;
//byte buf[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};//, 0x00, 0x00};
bool flag = false;
int addr_nhrs9 = 30;
const uint8_t EngineCommand = 8;
int eventstate=0;
float hmr=0.00;
int Eread;
void setup()
{
  Serial.begin(9600);
  Wire.begin(slaveAddress1);       
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
Wire.onReceive(receiveEvent);
pinMode(EngineCommand, INPUT);
}

void loop()
{
  if (flag == true){
 display.setCursor(0, 0);
 for (int r=0; r<5;r++){ 
  byte y = buf[r];
    display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  

  display.print(y);
   display.display();
   }
   flag == false;
  }
 
  delay(1000);
   if (digitalRead(EngineCommand) == HIGH){
   if( eventstate<1 )
   {
 addr_nhrs9=30;
for ( long int n = 0; n <5; n++) 
{
//buf[n] = Wire.read(); 
EEPROM.update(addr_nhrs9,buf[n]);
addr_nhrs9++;           
}
addr_nhrs9 = 30;
for (long int i = 0; i <5; i++)
{
long int Eread = EEPROM.read(addr_nhrs9);



addr_nhrs9++;
Serial.print(Eread);
}
 
 eventstate++;  
    
    }
    }
if (digitalRead(EngineCommand) == LOW){
  eventstate=0;
  }
 

}
void receiveEvent(int howMany)
{
 
  for (int i = 0; i <=5; i++)
    {

      buf[i] = Wire.read();   //"buf"need to convert an integar value
      byte x = buf[i];
    /*if (x < 0x10)
    {
      Serial.print('0');     //print leading zero
    }*/
    Serial.print(x);
    if (i == 3)
    {
      Serial.print('.');// show : as separator between Hrs and Min
    }
    else
    {
      if (i == 4)
      {
        Serial.print('.'); //show : as separator between Min and Sec
      }
     }
   
 
    }
  Serial.println();
  flag = true;
   
}

anon73444976 · January 22, 2020, 2:03pm

   flag == false;

Oops

Please, do yourself (and us) a favour, and use the IDE's auto-format tool before posting code.

Also, why are you using longs for loop controls, where you're only counting to 5?

sreekanthmp · January 22, 2020, 3:42pm

TheMemberFormerlyKnownAsAWOL:
where you're only counting to 5?

I need only hrs and minutes value for being able to do something with it.

TheMemberFormerlyKnownAsAWOL:
use the IDE's auto-format tool before posting code.

sorry .

TheMemberFormerlyKnownAsAWOL:
flag == false;[/code]
Oops

why are you using longs for loop controls,

After changing ..problem is not solved.

TheMemberFormerlyKnownAsAWOL:
Please, do yourself (and us) a favour.

Thank you for your reply.First of all i am not well expert in programming .i have made this program after referring several program from the google.So please help me to solve this problem.

this is my code MASTER

#include <EEPROM.h>
#include <Wire.h>

//#include <Wire.h>/////
#include "RTClib.h"///////////////////// rtc
RTC_DS3231 rtc;////////////////////////// rtc


const uint8_t Toggle = 23;
const uint8_t maint = 3;
const uint8_t EngineCommand = 8;

float value1;
float diffrRead = 0.0;
float Mvalue2;
float Mval;

unsigned long time_now = 0;
boolean already = false;




int EventState = 0;

int addr_secnd = 0;
int addr_Minute = 2;
int addr_hrs1 = 3;
int addr_hrs2 = 4;
int addr_hrs3 = 5;
int addr_hrs4 = 6;
int addr_hrs5 = 7;

int addr_hrs7 = 8;
int addr_hrs8 = 9;
int addr_hrs9 = 10;
int addr_hrs10 = 11;

int secnd = 0;
int Minute = 0;
int hrs1 = 0;
int hrs2 = 0;
int hrs3 = 0;
int hrs4 = 0;
int hrs5 = 0;
int value_secnd;
int value_Minute;
int value_hrs1;
int value_hrs2;
int value_hrs3;
int value_hrs4;

int x6;
int x7;
int x8;
int x9;
int x10;
byte ok;

int period = 100;
unsigned long previousMillis = 0;
unsigned long currentMillis;


long lastTime = 0;
long seconds = EEPROM.read(addr_secnd);
long minutes = EEPROM.read(addr_Minute);
long hours = EEPROM.read(addr_hrs2);
long hours1 = EEPROM.read(addr_hrs7);
long hours2 = EEPROM.read(addr_hrs8);
long hours3 = EEPROM.read(addr_hrs9);
bool button_State = false;//////////////////////////sd card

void setup()
{

  Serial.begin(9600);
  Wire.begin();

  pinMode(EngineCommand, INPUT);

}


void loop() {
  unsigned long startTimehmr = millis();


  currentMillis = millis();
  if (currentMillis - previousMillis >= period )
  {

    previousMillis += period;

    if (digitalRead(EngineCommand) == LOW)
    {
      EventState = 0;
      if (millis() - lastTime > 0)
      {
        seconds++;
        lastTime = millis();
      }
      if (seconds > 59)
      {

        minutes++;
        seconds = 0;

      }

      if (minutes > 59)
      {

        hours++;
        minutes = 0;
      }
      if (hours > 9)
      {

        hours1++;
        hours = 0;
      }
      if (hours1 > 9)
      {

        hours2++;
        hours1 = 0;
      }
      if (hours2 > 9)
      {

        hours3++;
        hours2 = 0;
      }
      byte myTime[6];
      myTime[0] = (hours3);
      myTime[1] = (hours2);
      myTime[2] = (hours1);
      myTime[3] = (hours);
      myTime[4] = (minutes);
      myTime[5] = (seconds);
      Wire.beginTransmission( 4 );                  // transmit to device #4
      Wire.write (myTime, sizeof(myTime));            // send data in natural binary to slave
      Wire.endTransmission();

      /*Serial.print(hours3);
        Serial.print(":");
        Serial.print(hours2);
        Serial.print(":");
        Serial.print(hours1);
        Serial.print(":");
        Serial.print(hours);
        Serial.print(":");
        Serial.print(minutes);
        Serial.print(".");
        Serial.println(seconds);
      */
    }

  }

  if (digitalRead(EngineCommand) == HIGH)
  {
    if (EventState < 1)
    {
      EEPROM.update(addr_secnd, seconds);
      //EEPROM.update(addr_secnd1, seconds1);
      EEPROM.update(addr_Minute, minutes);
      EEPROM.update(addr_hrs2, hours);
      EEPROM.update(addr_hrs7, hours1);
      EEPROM.update(addr_hrs8, hours2);
      EEPROM.update(addr_hrs9, hours3);
      EventState++;
    }





  }
}

SLAVE

#include <EEPROM.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

//#define VCCSTATE SH1106_SWITCHCAPVCC
#define WIDTH     128
#define HEIGHT     64
#define NUM_PAGE    8
#define NUMFLAKES 10
#define XPOS 0
#define YPOS 1
#define DELTAY 2
#define LOGO16_GLCD_HEIGHT 16
#define LOGO16_GLCD_WIDTH  16

const byte slaveAddress1 = 4;
byte buf[7] = {}; //;
//byte buf[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};//, 0x00, 0x00};
bool flag;// = false;
int addr_nhrs9 = 30;
const uint8_t EngineCommand = 8;
int eventstate = 0;
float hmr = 0.00;
int Eread;
void setup()
{
  Serial.begin(9600);
  Wire.begin(slaveAddress1);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  Wire.onReceive(receiveEvent);
  pinMode(EngineCommand, INPUT);
}

void loop()
{
  if (flag == true) {
    display.setCursor(0, 0);
    for (int r = 0; r < 5; r++) {
      byte y = buf[r];
      display.clearDisplay();
      display.setTextSize(1);
      display.setTextColor(WHITE);


      display.print(y);
      display.display();
    }
    flag == false;
  }

  delay(1000);
  if (digitalRead(EngineCommand) == HIGH) {
    if ( eventstate < 1 )
    {
      addr_nhrs9 = 30;
      for (int n = 0; n < 5; n++)
      {
        
        EEPROM.update(addr_nhrs9, buf[n]);
        addr_nhrs9++;
      }
      addr_nhrs9 = 30;
      for (int i = 0; i < 5; i++)
      {
         int Eread = EEPROM.read(addr_nhrs9);



        addr_nhrs9++;
        Serial.print(Eread);
      }

      eventstate++;

    }
  }
  if (digitalRead(EngineCommand) == LOW) {
    eventstate = 0;
  }


}
void receiveEvent(int howMany)
{

  for (int i = 0; i <= 5; i++)
  {

    buf[i] = Wire.read();   //"buf"need to convert an integar value
    byte x = buf[i];
    
    Serial.print(x);
    if (i == 3)
    {
      Serial.print('.');// show : as separator between Hrs and Min
    }
    else
    {
      if (i == 4)
      {
        Serial.print('.'); //show : as separator between Min and Sec
      }
    }


  }
  Serial.println();
  flag = true;

}

anon73444976 · January 22, 2020, 4:02pm

flag == false; Still oops

sreekanthmp · January 22, 2020, 4:44pm

TheMemberFormerlyKnownAsAWOL:
    flag == false;
Still oops

I think i include the flag in wrong position.

Now flag position changed but no improvement

SLAVE

#include <EEPROM.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

//#define VCCSTATE SH1106_SWITCHCAPVCC
#define WIDTH     128
#define HEIGHT     64
#define NUM_PAGE    8
#define NUMFLAKES 10
#define XPOS 0
#define YPOS 1
#define DELTAY 2
#define LOGO16_GLCD_HEIGHT 16
#define LOGO16_GLCD_WIDTH  16

const byte slaveAddress1 = 4;
byte buf[7] = {}; //;
byte  Eread[6] = {};

//byte buf[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};//, 0x00, 0x00};
bool flag = false;
int addr_nhrs9 = 30;
const uint8_t EngineCommand = 8;
int eventstate = 0;
float hmr = 0.00;
//int Eread;

void setup()
{
  Serial.begin(9600);
  Wire.begin(slaveAddress1);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  Wire.onReceive(receiveEvent);
  pinMode(EngineCommand, INPUT);

}

void loop()
{
  if (flag == true) {
    display.setCursor(0, 0);
    for (int r = 0; r < 5; r++) {
      byte y = buf[r];
      display.clearDisplay();
      display.setTextSize(1);
      display.setTextColor(WHITE);


      display.print(y);
      display.display();
    }


    if (digitalRead(EngineCommand) == HIGH) {
      if ( eventstate < 1 )
      {
        addr_nhrs9 = 30;
        for (int n = 0; n < 5; n++)
        {

          EEPROM.update(addr_nhrs9, buf[n]);
          addr_nhrs9++;
        }

        addr_nhrs9 = 30;
        for (int s = 0; s < 5; s++)
        {


          byte  Eread = {EEPROM.read(addr_nhrs9)};



          addr_nhrs9++;
          Serial.print(Eread);
        }
        Serial.println();
        eventstate++;

      }
    }
    if (digitalRead(EngineCommand) == LOW) {
      eventstate = 0;
    }
    delay(1000);
    flag == false;
  }


}
void receiveEvent(int howMany)
{

  for (int i = 0; i <= 5; i++)
  {

    buf[i] = Wire.read();   //"buf"need to convert an integar value
    byte x = buf[i];

    Serial.print(x);
    if (i == 3)
    {
      Serial.print('.');// show : as separator between Hrs and Min
    }
    else
    {
      if (i == 4)
      {
        Serial.print('.'); //show : as separator between Min and Sec
      }
    }


  }
  Serial.println();
  flag = true;

}

dougp · January 22, 2020, 4:49pm

sreekanthmp:
I think i include the flag in wrong position.

Now flag position changed but no improvement

== and = are not the same thing.

sreekanthmp · January 22, 2020, 5:18pm

dougp:
== and = are not the same thing.

thanks,

after correction , following problem not solved.

I want to assign the slave's EEPROM stored value on a float variable. When i reading this value,this showing on serial monitor like this 000135 . I need to assign this value to a float variable this format (1.35) 1 hrs 35 minute.

Another problem is that when i switch off and on the SLAVE arduino .slave EEPROM value become Serial zero.

UKHeliBob · January 22, 2020, 5:58pm

Each EEPROM location can only store one byte, not a float
You can save a float to the EEPROM using EEPROM.put() and load it back with EEPROM.get()

sreekanthmp · January 22, 2020, 6:09pm

UKHeliBob:
Each EEPROM location can only store one byte, not a float
You can save a float to the EEPROM using EEPROM.put() and load it back with EEPROM.get()

Ok.
For example my meter readings is 1hr 35 minutes
Reading is 000135.
Write to eeprom address
0-> EEPROM address-30
0-> EEPROM address-31
0-> EEPROM address-32
1-> EEPROM address-33
3-> EEPROM address-34
5-> EEPROM address-35

When I read the value from those adress (eeprmRead)
Its showing 000135.
Now i want to assign this value to a float variable this format 0001.35 is it possible?

anon73444976 · January 22, 2020, 6:24pm

Yes it is possible, but probably unnecessary (and even undesirable)
Assign the digit values to an integer.

sreekanthmp · January 22, 2020, 6:34pm

TheMemberFormerlyKnownAsAWOL:
Yes it is possible, but probably unnecessary (and even undesirable)
Assign the digit values to an integer.

I need this , because i want to send the running hours sms through gsm module on that format (0001.35).Apart from i want to substract the current running hrsfrom pre set value
Example :- pre set value is 10.00hrs
Substracting running hours ,=(10.00hrs - current running hours).

For all these purpose i want to change hrs 000135 format to 0001.35 format

anon73444976 · January 22, 2020, 6:38pm

sreekanthmp:
I need this

But ask yourself if you really do, or if you just need that representation when you present the value to a human.

sreekanthmp · January 23, 2020, 8:09am

TheMemberFormerlyKnownAsAWOL:
But ask yourself if you really do, or if you just need that representation when you present the value to a human.

i have done some modification now its showing on serial monitor ,same format which i need.

here is slave code:-

#include <EEPROM.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define OLED_RESET 4
Adafruit_SSD1306 display(OLED_RESET);

//#define VCCSTATE SH1106_SWITCHCAPVCC
#define WIDTH     128
#define HEIGHT     64
#define NUM_PAGE    8
#define NUMFLAKES 10
#define XPOS 0
#define YPOS 1
#define DELTAY 2
#define LOGO16_GLCD_HEIGHT 16
#define LOGO16_GLCD_WIDTH  16

const byte slaveAddress1 = 4;
byte buf[7] = {};
byte  Eread[6] = {};

//byte Eread[] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00};//, 0x00, 0x00};
bool flag = false;
int addr_nhrs9 = 30;
const uint8_t EngineCommand = 8;
int eventstate = 0;
float hmr = 0.00;
//int Eread;

void setup()
{
  Serial.begin(9600);
  Wire.begin(slaveAddress1);
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  Wire.onReceive(receiveEvent);
  pinMode(EngineCommand, INPUT);

}

void loop()
{
  if (flag = true) {
    display.setCursor(0, 0);
    for (int r = 0; r < 5; r++) {
      byte y = buf[r];
      display.clearDisplay();
      display.setTextSize(1);
      display.setTextColor(WHITE);


      display.print(y);
      display.display();
    }


    if (digitalRead(EngineCommand) == HIGH) {
      if ( eventstate < 1 )
      {
        addr_nhrs9 = 30;
        for (int n = 0; n < 5; n++)
        {

          EEPROM.update(addr_nhrs9, buf[n]);
          addr_nhrs9++;
        }

        addr_nhrs9 = 30;
        for (int s = 0; s < 5; s++)
        {


          Eread[s] = {EEPROM.read(addr_nhrs9)};




          addr_nhrs9++;


          Serial.print (Eread[s]);
           
          
          if (s == 3)
          {
            Serial.print('.');// show : as separator between Hrs and Min
          }
          else
          {

          }

        }
        
        Serial.println();
        
        eventstate++;

      }

    }
    if (digitalRead(EngineCommand) == LOW) {
      eventstate = 0;
    }
  }
  delay(1000);
  flag = false;
}



void receiveEvent(int howMany)
{

  for (int i = 0; i <= 5; i++)
  {

    buf[i] = Wire.read();   //"buf"need to convert an integar value
    byte x = buf[i];

    Serial.print(x);
    if (i == 3)
    {
      Serial.print('.');// show : as separator between Hrs and Min
    }
    else
    {
      if (i == 4)
      {
        Serial.print('.'); //show : as separator between Min and Sec
      }
    }


  }
  Serial.println();
  flag = true;

}

serial monitor shows :-

that is the value is 2.27.But how can assign this value to float variable?

anon73444976 · January 23, 2020, 8:24am

Well, one way would be to assign it to an integer, and then divide by 100 and assign that value to a float.
But it is probably simpler to leave it as an integer.

anon73444976 · January 23, 2020, 9:03am

if (flag = true) { Again, ooops

sreekanthmp · January 23, 2020, 9:26am

TheMemberFormerlyKnownAsAWOL:
Well, one way would be to assign it to an integer, and then divide by 100 and assign that value to a float.
But it is probably simpler to leave it as an integer.

Now i have assigned this value to an integar (int hmr) and print in the serial monitor.But this converted the single value of an array in to integar one by one.in place of all array value in one time.

for example array value is 2.31 and its convert first value 2 and 31.

if i want to substract set value 1 from above integar, it will substract first from the value 2 and than 31.its not correct.

I need substraction like this (2.31-1=1.31)....still problem is existing ..please advice how to solve

serial monitor:-

0000000.000
0002.32.11
0002.32.12
0002.32.13
0002.32.14
0002.32.15
0002.32.16
0002.32.17
0002.32.18
0002.32.19
0002.32.20
0002.32.21
0000002.23232

anon73444976 · January 23, 2020, 9:32am

I'm sorry I don't understand.

If you keep the value as an integer, then you must scale other operands by 100 too.

So, if 231 represents 2.31 (hh.mm), then to decrement the hours, subtract 100.

Or forget about hh.mm, and just work in minutes.
Or seconds.

sreekanthmp · January 23, 2020, 9:40am

TheMemberFormerlyKnownAsAWOL:
I'm sorry I don't understand.

If you keep the value as an integer, then you must scale other operands by 100 too.

So, if 231 represents 2.31 (hh.mm), then to decrement the hours, subtract 100.

Or forget about hh.mm, and just work in minutes.
Or seconds.

[b]0000000.000[/b]
0002.32.11
0002.32.12
0002.32.13
0002.32.14
0002.32.15
0002.32.16
0002.32.17
0002.32.18
0002.32.19
0002.32.20
0002.32.21
[b]0000002.23232[/b]

this serial monitor shows integar value and array value (letters in Bold) in single line.First i need to print array value and integar value separate single line.

anon73444976 · January 23, 2020, 10:18am

Are you saying you need to print a space or tab, or a newline?

sreekanthmp · January 23, 2020, 10:28am

TheMemberFormerlyKnownAsAWOL:
Are you saying you need to print a space or tab, or a newline?

New line

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Problem facing in EEPROM Reading with Arduino UNO

when i reading this value,this showing on serial monitor like this 000135.I want to put "." decimal mark between hour and Minutes. {1.35}.

Another problem is that when i switch off and on the SLAVE arduino .Serial monitor shows zero reading.

I want to assign the slave's EEPROM stored value on a float variable. When i reading this value,this showing on serial monitor like this 000135 . I need to assign this value to a float variable this format (1.35) 1 hrs 35 minute.

Another problem is that when i switch off and on the SLAVE arduino .slave EEPROM value become Serial zero.

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