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Topic: Water Flow meter &EEPROM (Read 239 times) previous topic - next topic

Ahmed_Ali1955

hello Friends
any one can help me in how to store total of liters count in arduino eeprom ;Problem When arduino mega has turned off ;
the stored value of liters returns to 0

Code: [Select]
/*
Liquid flow rate sensor -DIYhacking.com Arvind Sanjeev

Measure the liquid/water flow rate using this code.
Connect Vcc and Gnd of sensor to arduino, and the
signal line to arduino digital pin 2.
 
 */
#include <EEPROM.h>
byte statusLed    = 13;

byte sensorInterrupt = 0;  // 0 = digital pin 2
byte sensorPin       = 2;

// The hall-effect flow sensor outputs approximately 4.5 pulses per second per
// litre/minute of flow.
float calibrationFactor = 4.5;

volatile byte pulseCount; 

float flowRate;
unsigned int flowMilliLitres;
unsigned long totalMilliLitres;

unsigned long oldTime;

void setup()
{
 
  // Initialize a serial connection for reporting values to the host
  Serial.begin(9600);
   
  // Set up the status LED line as an output
  pinMode(statusLed, OUTPUT);
  digitalWrite(statusLed, HIGH);  // We have an active-low LED attached
 
  pinMode(sensorPin, INPUT);
  digitalWrite(sensorPin, HIGH);

  pulseCount        = 0;
  flowRate          = 0.0;
  flowMilliLitres   = 0;
  totalMilliLitres  = 0;
  oldTime           = 0;

  // The Hall-effect sensor is connected to pin 2 which uses interrupt 0.
  // Configured to trigger on a FALLING state change (transition from HIGH
  // state to LOW state)
  attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
  if (EEPROM.read(0) != 0xFF){
  EEPROM.put(1,totalMilliLitres);
}
}
/**
 * Main program loop
 */
void loop()
{
   
   if((millis() - oldTime) > 1000)    // Only process counters once per second
  {
    // Disable the interrupt while calculating flow rate and sending the value to
    // the host
    detachInterrupt(sensorInterrupt);
       
    // Because this loop may not complete in exactly 1 second intervals we calculate
    // the number of milliseconds that have passed since the last execution and use
    // that to scale the output. We also apply the calibrationFactor to scale the output
    // based on the number of pulses per second per units of measure (litres/minute in
    // this case) coming from the sensor.
    flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
   
    // Note the time this processing pass was executed. Note that because we've
    // disabled interrupts the millis() function won't actually be incrementing right
    // at this point, but it will still return the value it was set to just before
    // interrupts went away.
    oldTime = millis();
   
    // Divide the flow rate in litres/minute by 60 to determine how many litres have
    // passed through the sensor in this 1 second interval, then multiply by 1000 to
    // convert to millilitres.
    flowMilliLitres = (flowRate / 60) * 1000;
   
    // Add the millilitres passed in this second to the cumulative total
    totalMilliLitres += flowMilliLitres;
     
    unsigned int frac;
   
    // Print the flow rate for this second in litres / minute
    Serial.print("Flow rate: ");
    Serial.print(int(flowRate));  // Print the integer part of the variable
    Serial.print("L/min");
    Serial.print("\t");       // Print tab space

    // Print the cumulative total of litres flowed since starting
    Serial.print("Output Liquid Quantity: ");       
    Serial.print(totalMilliLitres);
    Serial.println("mL");
    Serial.print("\t");       // Print tab space
  Serial.print(totalMilliLitres/1000);
  Serial.print("L");
    EEPROM.write(1,totalMilliLitres);
    // Reset the pulse counter so we can start incrementing again
    pulseCount = 0;
   
    // Enable the interrupt again now that we've finished sending output
    attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
  }
}

/*
Insterrupt Service Routine
 */
void pulseCounter()
{
  // Increment the pulse counter
  pulseCount++;
}

cattledog

Code: [Select]
unsigned long totalMilliLitres;

An unsigned long is 4 bytes. You should be using EEPROM.put() and EEPROM.get() to handle this. Please review the library examples for EEPROM.h.

 
Code: [Select]
totalMilliLitres  = 0;

if (EEPROM.read(0) != 0xFF){
  EEPROM.put(1,totalMilliLitres); //place 4 bytes of 0 in eeprom cells 1:4.



Code: [Select]
EEPROM.write(1,totalMilliLitres); //need to use EEPROM.put() to store 4 bytes

Quote
Problem When arduino mega has turned off ;
the stored value of liters returns to 0
No where in your code do you read the value with EEPROM.get()

Ahmed_Ali1955

i did that but still same issue due to the value of totalMilliLitres return to 0 after powered off

cattledog

Please provide your latest code.

Can you successfully run the example programs for EEPROM.h to store and retrieve values?

If you can successfully run the example programs, can you read the values you stored after a power cycle?


Ahmed_Ali1955

Can you successfully run the example programs for EEPROM.h to store and retrieve values?
yes

If you can successfully run the example programs, can you read the values you stored after a power cycle?

no the value return to 0


Code: [Select]
#include <EEPROM.h>
byte statusLed    = 13;

byte sensorInterrupt = 0;  // 0 = digital pin 2
byte sensorPin       = 2;

// The hall-effect flow sensor outputs approximately 4.5 pulses per second per
// litre/minute of flow.
float calibrationFactor = 4.5;

volatile byte pulseCount; 

float flowRate;
unsigned int flowMilliLitres;
unsigned long totalMilliLitres;

unsigned long oldTime;

void setup()
{
 
  // Initialize a serial connection for reporting values to the host
  Serial.begin(9600);
   
  // Set up the status LED line as an output
  pinMode(statusLed, OUTPUT);
  digitalWrite(statusLed, HIGH);  // We have an active-low LED attached
 
  pinMode(sensorPin, INPUT);
  digitalWrite(sensorPin, HIGH);

  pulseCount        = 0;
  flowRate          = 0.0;
  flowMilliLitres   = 0;
  totalMilliLitres  = 0;
  oldTime           = 0;

  // The Hall-effect sensor is connected to pin 2 which uses interrupt 0.
  // Configured to trigger on a FALLING state change (transition from HIGH
  // state to LOW state)
  attachInterrupt(sensorInterrupt, pulseCounter, FALLING);


// ############################################
// ############################################
// Initiaize the value of totalMilliLiters
  if (EEPROM.read(0) != 0xFF){           
      EEPROM.put(1,totalMilliLitres); 
} else {
      EEPROM.get(1,totalMilliLitres);
}
    Serial.println("Startup EPROM Value  :");
    Serial.print("Output Liquid Quantity: ");       
    Serial.println(totalMilliLitres);
// ############################################
}
/**
 * Main program loop
 */
void loop()
{
   
   if((millis() - oldTime) > 1000)    // Only process counters once per second
  {
    // Disable the interrupt while calculating flow rate and sending the value to
    // the host
    detachInterrupt(sensorInterrupt);
       
    // Because this loop may not complete in exactly 1 second intervals we calculate
    // the number of milliseconds that have passed since the last execution and use
    // that to scale the output. We also apply the calibrationFactor to scale the output
    // based on the number of pulses per second per units of measure (litres/minute in
    // this case) coming from the sensor.
    flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
   
    // Note the time this processing pass was executed. Note that because we've
    // disabled interrupts the millis() function won't actually be incrementing right
    // at this point, but it will still return the value it was set to just before
    // interrupts went away.
    oldTime = millis();
   
    // Divide the flow rate in litres/minute by 60 to determine how many litres have
    // passed through the sensor in this 1 second interval, then multiply by 1000 to
    // convert to millilitres.
    flowMilliLitres = (flowRate / 60) * 1000;
   
    // Add the millilitres passed in this second to the cumulative total
    totalMilliLitres += flowMilliLitres;
     
    unsigned int frac;
   
    // Print the flow rate for this second in litres / minute
    Serial.print("Flow rate: ");
    Serial.print(int(flowRate));  // Print the integer part of the variable
    Serial.print("L/min");
    Serial.print("\t");       // Print tab space

    // Print the cumulative total of litres flowed since starting
    Serial.print("Output Liquid Quantity: ");       
    Serial.print(totalMilliLitres);
    Serial.print("mL");
    Serial.print("\t");       // Print tab space
  Serial.print(totalMilliLitres/1000);
  Serial.println("L");

  // ######################################################
  // ######################################################
  // Save the Value in EEPROM
    EEPROM.put(1,totalMilliLitres);           //  Was read value  EEPROM.get(1,totalMilliLitres);
  // ######################################################
  // ######################################################
    // Reset the pulse counter so we can start incrementing again
    pulseCount = 0;
   
    // Enable the interrupt again now that we've finished sending output
    attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
  }
}

/*
Insterrupt Service Routine
 */
void pulseCounter()
{
  // Increment the pulse counter
  pulseCount++;
}

cattledog

Quote
If you can successfully run the example programs, can you read the values you stored after a power cycle?
no the value return to 0
What you are experiencing is is very unusual. 

There are some possible issues if the Vcc is low. How is the mega being powered?

What is the history of the Mega? Is it new?  Who is the manufacturer? Has the eeprom previously worked correctly? What happens when you restart the program with a reset?

I would suggest trying to store the data at an eeprom address not at the beginning of the address sequence, in case there was some sort of previous programming error which used up the lifetime of the memory where you are trying to place your data.




Ahmed_Ali1955

my problem solved after change megae borad to new one

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