Energy Meter - not sending at expected

[flopp]

@sundberg84
i also had a lot of problem with my Rain data in Domoticz.
read more here https://www.domoticz.com/forum/viewtopic.php?f=28&t=11088

if your Sensor timeout is 2 hours you need to send rain VAR within 2 hours otherwise your graph will look strange.

Yes, if you change the VAR during the day to a lower value you will get minus value. Took me a few days to understand how Domoticz DB file was working.

Keep up the good work :punch:

[flopp]

It was working for a few hours then not sending any data, even with my new sketch. I changed to Arduino UNO and since then it has been working perfect. So it was my NRF(maybe) and my Nano that was not working correctly.

[flopp]

But I found something weird about the division

Why doesn't it send the exact value?

My pulseCount is 1845124894 and it is sent to Controller correct, then it will use below function
My PULSE_FACTOR is 10000

double kwh = ((double)pulseCount/((double)PULSE_FACTOR));

and send the divided value to Controller, but it doesn't send correct value, it is missing the two last numbers "94" it is absolutely not a big problem but why send 4 decimals when the two last it always 0(zero)

Look at last row, 1845125113 = 184512.5200?

Is this because double values is rounding up? But 5113 should be 5100.

[Yveaux]

@flopp could be because 'double' is actually float on Arduino, and therefore precision is limited. Have to do so maths though to know for sure.

[flopp]

@Yveaux
OK thanks

[flopp]

still working with UNO.

this is the sketch i am running

#include <SPI.h>
#include <MySensor.h>  

#define DIGITAL_INPUT_SENSOR 3  // The digital input you attached your light sensor.  (Only 2 and 3 generates interrupt!)
#define PULSE_FACTOR 10000       // Nummber of blinks per KWH of your meeter
#define SLEEP_MODE false        // Watt-value can only be reported when sleep mode is false.
#define MAX_WATT 15000          // Max watt value to report. This filetrs outliers.
#define INTERRUPT DIGITAL_INPUT_SENSOR-2 // Usually the interrupt = pin -2 (on uno/nano anyway)
#define CHILD_ID 1              // Id of the sensor child
unsigned long SEND_FREQUENCY = 5*60000; // Minimum time between send (in milliseconds). We don't wnat to spam the gateway.
MySensor gw;
double ppwh = ((double)PULSE_FACTOR)/1000; // Pulses per watt hour
boolean pcReceived = false;
volatile unsigned long pulseCount = 0;   
volatile unsigned long lastBlink = 0;
volatile unsigned long watt = 0;
unsigned long oldPulseCount = 0;   
unsigned long oldWatt = 0;
double oldKwh;
unsigned long lastSend;
MyMessage wattMsg(CHILD_ID,V_WATT);
MyMessage kwhMsg(CHILD_ID,V_KWH);
MyMessage pcMsg(CHILD_ID,V_VAR1);


void setup()  
{  
  gw.begin(incomingMessage);

  // Send the sketch version information to the gateway and Controller
  gw.sendSketchInfo("Energy Meter", "1.1");
  //1.1 no check for old value, always send
  
  // Register this device as power sensor
  gw.present(CHILD_ID, S_POWER);

  // Fetch last known pulse count value from gw
  gw.request(CHILD_ID, V_VAR1);
  
  attachInterrupt(INTERRUPT, onPulse, RISING);
  lastSend=millis();
}


void loop()     
{ 
  gw.process();
  unsigned long now = millis();
  // Only send values at a maximum frequency or woken up from sleep
  bool sendTime = now - lastSend > SEND_FREQUENCY;
  if (pcReceived && (SLEEP_MODE || sendTime)) {
    
    // New watt value has been calculated  
       
    // Check that we dont get unresonable large watt value. 
    // could hapen when long wraps or false interrupt triggered
    if (watt<((unsigned long)MAX_WATT)) {
    
      gw.send(wattMsg.set(watt));  // Send watt value to gw 
    }  
    Serial.print("Watt:");
    Serial.println(watt);
    oldWatt = watt;
     
    // Pulse cout has changed
    
    if (pulseCount != oldPulseCount) {
    
      gw.send(pcMsg.set(pulseCount));  // Send pulse count value to gw 
      double kwh = ((double)pulseCount/((double)PULSE_FACTOR));     
      oldPulseCount = pulseCount;
         
      gw.send(kwhMsg.set(kwh, 4));  // Send kwh value to gw 
      oldKwh = kwh;
      
    }    
    lastSend = now;
  } else if (sendTime && !pcReceived) {
    // No count received. Try requesting it again
    gw.request(CHILD_ID, V_VAR1);
    lastSend=now;
  }
  
  if (SLEEP_MODE) {
    gw.sleep(SEND_FREQUENCY);
  }
}

void incomingMessage(const MyMessage &message) {
  if (message.type==V_VAR1) {  
    pulseCount = oldPulseCount = message.getLong();
    Serial.print("Received last pulse count from gw:");
    Serial.println(pulseCount);
    pcReceived = true;
  }
}

void onPulse()     
{ 
  if (!SLEEP_MODE) {
    unsigned long newBlink = micros();  
    unsigned long interval = newBlink-lastBlink;
    if (interval<10000L) { // Sometimes we get interrupt on RISING
      return;
    }
    watt = (3600000000.0 /interval) / ppwh;
    
    lastBlink = newBlink;
  } 
  pulseCount++;
}

[flopp]

There must be something wrong with my code. Since 1 February my Arduino is 3 kWh before the real energy value for my house.
My second Arduino is measuring kWh on my heating system and that one is running correct.
For my house I use Nano(clone) for heating system I use UNO(original)
Can the hardware be the bad guy here?
It should be same code in both Arduino but tomorrow I will use an UNO(org) for my house and wait 1 week.

[Yveaux]

@flopp how do you count the pulses from your meter? Could that be the issue?

[flopp]

@Yveaux
I don't know the name but I think it is a photo resistor, which I have connected to a LM393 then Arduino counts the interrupts.
Same hardware for both House and Heating.
Same sketch.

[flopp]

I changed to a UNO now my Watt is showing the same value!!
EDIT: this was because the WATT was above 15000 and then it didn't send any data to Controller. I had values up to 110000.
It must be something with the Watt calculation. Anyone seen this before?

[flopp]

I think I found it.

if (interval<10000L) { // Sometimes we get interrupt on RISING
      return;
    }

It seems to be that my interrupt is to quick. above code is default if I change to

if (interval<35000L) { // Sometimes we get interrupt on RISING
      return;
    }

it will calculate Watt as I think it should be.
I will let it run for a week and see if kWh is OK now.