cannot save water meter in arduino EEPROM



  • 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


  • Mod

    Hi @ahmedhodhod, welcome to the forum!

    The water meter example fetches the last count from the controller at startup. Isn't that sufficient?



  • unfortunately not;
    i need to store in arduino eeprom and iam using this sensor

    0_1531062888197_Steel-Water-Flow-Sensor-.jpg


  • Mod

    @ahmedhodhod could you expand on why fething the value from the controller is insufficient?



  • i'm use the below code but the main problem.when arduino powered off the value of ''totalMilliLitres'' stored return to 0

    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.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++;
    }
    
    


  • @ahmedhodhod Your not writing any data to the EEPROM.

    You missing the following in the main loop

        EEPROM.put(1,totalMilliLitres); 
    

    See changes in code.

    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);
    
    
    // ############################################
    // ############################################
    // Initiaize the value of totalMilliLiters 
      if (EEPROM.read(0) != 0xFF){
      EEPROM.put(1,totalMilliLitres);
    } else {
          EEPROM.get(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");
    
      // ######################################################
      // ######################################################
      // 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++;
    }
    

    The code blocks the interrupt for a long time during which the incoming pulses will be lost.
    it should be better to grab the pulse count and reset, and process the calculation and printing outside of the interrupt blocking.
    Writing to the EEPROM every second will cause wear.
    There is no MySensors code in this, What controller are you using?
    As mfalkvidd stated getting the value from the controller on start up is my preferred method.



  • @hard-shovel said in cannot save water meter in arduino EEPROM:

    controller

    same issue with your modification in the code & the controller are using arduino mega 2560



  • @ahmedhodhod For controller I meant automation controller ie OpenHAB, Domoticz, etc

    I made an error in the start up section with the not equals test.

    // ############################################
    // ############################################
    // Initiaize the value of totalMilliLiters 
      if (EEPROM.read(0) == 0xFF){            // #### was 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);
    // ############################################
    

    Try this complete code, It works for me

    /*
    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);
    
    
    // ############################################
    // ############################################
    // Initiaize the value of totalMilliLiters 
      if (EEPROM.read(0) == 0xFF){            // #### was 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++;
    }
    


  • unfortunately cannot read the values that stored after a power cycle



  • @ahmedhodhod Sorry about that. When i tried the code above it was with a used board and the eprom already had data stored so worked fine.

    I have just tried with a brand new sealed mega board and had the same problem as you.

    The eprom test location and the save locations need to be the same, We were testing location 0 but saving to location 1.

    Change line 55 to the following

      if (EEPROM.read(1) == 0xFF){            // #### was if (EEPROM.read(0) != 0xFF) needs to the location as the save position
    
    

    if all is ok you should get an output on reboot like this..

    Startup EPROM Value  :
    Output Liquid Quantity: 0
    Flow rate: 0L/min	Output Liquid Quantity: 0mL	0L
    Flow rate: 2L/min	Output Liquid Quantity: 48mL	0L
    Flow rate: 39L/min	Output Liquid Quantity: 714mL	0L
    Flow rate: 29L/min	Output Liquid Quantity: 1209mL	1L
    Flow rate: 27L/min	Output Liquid Quantity: 1667mL	1L
    Flow rate: 27L/min	Output Liquid Quantity: 2133mL	2L
    Startup EPROM Value  :
    Output Liquid Quantity: 2133
    Flow rate: 1L/min	Output Liquid Quantity: 2162mL	2L
    Flow rate: 0L/min	Output Liquid Quantity: 2162mL	2L
    Flow rate: 18L/min	Output Liquid Quantity: 2469mL	2L
    Flow rate: 25L/min	Output Liquid Quantity: 2894mL	2L
    Startup EPROM Value  :
    Output Liquid Quantity: 2894
    Flow rate: 19L/min	Output Liquid Quantity: 3223mL	3L
    Flow rate: 17L/min	Output Liquid Quantity: 3511mL	3L
    Flow rate: 19L/min	Output Liquid Quantity: 3836mL	3L
    Flow rate: 4L/min	Output Liquid Quantity: 3917mL	3L
    Flow rate: 0L/min	Output Liquid Quantity: 3917mL	3L
    Flow rate: 32L/min	Output Liquid Quantity: 4453mL	4L
    Startup EPROM Value  :
    Output Liquid Quantity: 4453
    Flow rate: 0L/min	Output Liquid Quantity: 4460mL	4L
    Flow rate: 0L/min	Output Liquid Quantity: 4460mL	4L
    Flow rate: 0L/min	Output Liquid Quantity: 4460mL	4L
    
    


  • @hard-shovel said in cannot save water meter in arduino EEPROM:

    if (EEPROM.read(0) == 0xFF){

    thanks it working now but cannot read more than 8 digits number



  • PLease, DON’T write to eeprom in the loop(), you will destroy the eeprom. The lifecycle for the eeprom is 100000 writes/read, after that it is destroyed.
    info about eeprom writes at arduino

    EDIT: With the current code (write to eeprom every second) the eeprom will be destroyed after aprox 69 days.



  • i know that but the problem now how to write 8 digits in eeprom





  • @ahmedhodhod did it work with the suggested links?



  • @mickecarlsson
    I do not think the actual problem is with writing the EEPROM, as the EEPROM.put function is used and this will Write any data type or object to the EEPROM.

        EEPROM.put(1,totalMilliLitres);
    

    as the totalMilliLitres is already an unsigned variable that should be good for up to ten digits.

    unsigned long totalMilliLitres;      // unsigned long  max 4,294,967,294 on UNO/Mega
    

    The only problem area i can see is the use of

    volatile byte pulseCount;
    

    which severely limits the pulse counts to 255 and whould be better as

    volatile unsigned int pulseCount;      // volatile byte pulseCount;  byte max 255
    

    More clarification of the actual problem is needed.


 

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