💬 Power Meter Pulse Sensor

gohan

it is the one in https://www.mysensors.org/build/pulse_power

mickecarlsson

How is the pulse counter set up? Is it connected to the S0 port?
Edit:
If you are using S0 it is vital that you use a pull down resistor, if you dont’t have that you get false pulses.
pulse connection

gohan

I'm using the lm393 light detector. Domoticz is able to do a calculation from the pulses to give a Watt value and it is correct but it does it every 5 minutes and it is too slow for me

sundberg84

@gohan - is Domoticz updating anything (except switches) faster than 5 min? I dont think so...

gohan

If you send the watt reading faster it updates like the switch, anyway I need the watt values for node-red also

gohan

Could it be the Light sensor is triggering more interrupts from each pulse?

henninne

@niklaso

Hi Niklas,

I know this is a very old post, but its worth a try. How did you get out the daily Kwh usage? As default my sensor only gives Watts and Kwh (accumulated from start), I have tried to run a Scene in Vera UI7 where there are a function in the sensor called resetKWh(), but it looks like it doesn't do anything. Any tips would be great, thanks.

Henning

smilvert

@gohan I think it is a little tricky to update domoticz every minute but try update the sql-file, see the domoticz forum
https://www.domoticz.com/forum/viewtopic.php?t=10183

gohan

The main issue is the fact that the sensor is not calculating the instant power correctly

DaTim69

I created this kWh sensor with the TCRT5000 IR Barrier Line Track Sensor.
My powermeter is a ferarrismeter with 375 rotations per kWh.
I also had the problem with spikes in the power usage. But after long...too long investigation I solved the problem.
At my config it was a double issue.

Issue 1.
The problem is the pulse width of the rotation.
The pulse are at night ( low power) much wider that during the day when more power is consumed. At night the spikes in power usage where huge.

Issue 2.
Switching on/off the halogen light causes spikes and related to also strange power measurement.

Solution:
I added a second arduino mini pro as a pulse regulator between the TCRT5000 and the power meter arduino.
this arduino triggers on Rising and will always give a 100ms puls. Als debounce is handled (spikes).
I don't upload the sketch here, I'm a beginning programmer on arduino. It's made on " trail and error" but it functions as it supposed to do.
If someone wants a copy feel free to contact mee

xydix

@gohan Did you solve this?
I get very high watt usage as well. Sometimes like 40 000 - 130 000 watt if I check the serial monitor.
Of course, those values will never be sent to the controler.

gohan

Nope, I am looking at other things now. Very little time available for too many things. I'm looking at buying CT clamp and do a more direct measurement.

xydix

Okay. Really annoying. Check this.

Received last pulse count from gw:2527
Watt:121065
22235 TSF:MSG:SEND,78-78-0-0,s=3,c=1,t=24,pt=5,l=4,sg=0,ft=0,st=OK:2539
22246 TSF:MSG:SEND,78-78-0-0,s=2,c=1,t=18,pt=7,l=5,sg=0,ft=0,st=OK:2.5390
Watt:121621
42238 TSF:MSG:SEND,78-78-0-0,s=3,c=1,t=24,pt=5,l=4,sg=0,ft=0,st=OK:2551
42250 TSF:MSG:SEND,78-78-0-0,s=2,c=1,t=18,pt=7,l=5,sg=0,ft=0,st=OK:2.5510
Watt:121342
62239 TSF:MSG:SEND,78-78-0-0,s=3,c=1,t=24,pt=5,l=4,sg=0,ft=0,st=OK:2563
62251 TSF:MSG:SEND,78-78-0-0,s=2,c=1,t=18,pt=7,l=5,sg=0,ft=0,st=OK:2.5630
Watt:121539
82240 TSF:MSG:SEND,78-78-0-0,s=3,c=1,t=24,pt=5,l=4,sg=0,ft=0,st=OK:2575
82251 TSF:MSG:SEND,78-78-0-0,s=2,c=1,t=18,pt=7,l=5,sg=0,ft=0,st=OK:2.5750
Watt:121951
102239 TSF:MSG:SEND,78-78-0-0,s=3,c=1,t=24,pt=5,l=4,sg=0,ft=0,st=OK:2589
102250 TSF:MSG:SEND,78-78-0-0,s=2,c=1,t=18,pt=7,l=5,sg=0,ft=0,st=OK:2.5890
Watt:122067
122243 TSF:MSG:SEND,78-78-0-0,s=3,c=1,t=24,pt=5,l=4,sg=0,ft=0,st=OK:2601
122254 TSF:MSG:SEND,78-78-0-0,s=2,c=1,t=18,pt=7,l=5,sg=0,ft=0,st=OK:2.6010

The plus count seems OK, right?

My energy meter is 1000 pluses /kwh

Here is my sketch. I use Home assistant so i created three sensors for this as I don't think V_VAR1 is supported with S_POWER.
Otherwise it is the standard example.

/**
 * The MySensors Arduino library handles the wireless radio link and protocol
 * between your home built sensors/actuators and HA controller of choice.
 * The sensors forms a self healing radio network with optional repeaters. Each
 * repeater and gateway builds a routing tables in EEPROM which keeps track of the
 * network topology allowing messages to be routed to nodes.
 *
 * Created by Henrik Ekblad <henrik.ekblad@mysensors.org>
 * Copyright (C) 2013-2015 Sensnology AB
 * Full contributor list: https://github.com/mysensors/Arduino/graphs/contributors
 *
 * Documentation: http://www.mysensors.org
 * Support Forum: http://forum.mysensors.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 *******************************
 *
 * REVISION HISTORY
 * Version 1.0 - Henrik EKblad
 *
 * DESCRIPTION
 * This sketch provides an example how to implement a distance sensor using HC-SR04
 * Use this sensor to measure KWH and Watt of your house meeter
 * You need to set the correct pulsefactor of your meeter (blinks per KWH).
 * The sensor starts by fetching current KWH value from gateway.
 * Reports both KWH and Watt back to gateway.
 *
 * Unfortunately millis() won't increment when the Arduino is in
 * sleepmode. So we cannot make this sensor sleep if we also want
 * to calculate/report watt-number.
 * http://www.mysensors.org/build/pulse_power
 */

// Enable debug prints
#define MY_DEBUG

// Enable and select radio type attached
#define MY_RADIO_NRF24
//#define MY_RADIO_RFM69
#define MY_NODE_ID 78
#include <MySensors.h>

#define DIGITAL_INPUT_SENSOR 3  // The digital input you attached your light sensor.  (Only 2 and 3 generates interrupt!)
#define PULSE_FACTOR 1000       // 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 20000          // Max watt value to report. This filetrs outliers.
#define WATT_CHILD_ID 1              // Id of the sensor child
#define KWH_CHILD_ID 2
#define PC_CHILD_ID 3

unsigned long SEND_FREQUENCY =
    20000; // Minimum time between send (in milliseconds). We don't wnat to spam the gateway.
double ppwh = ((double)PULSE_FACTOR)/1000; // Pulses per watt hour
bool 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(WATT_CHILD_ID,V_WATT);
MyMessage kwhMsg(KWH_CHILD_ID,V_KWH);
MyMessage pcMsg(PC_CHILD_ID,V_VAR1);


void setup()
{
  // Fetch last known pulse count value from gw
  request(PC_CHILD_ID, V_VAR1);

  // Use the internal pullup to be able to hook up this sketch directly to an energy meter with S0 output
  // If no pullup is used, the reported usage will be too high because of the floating pin
  pinMode(DIGITAL_INPUT_SENSOR,INPUT_PULLUP);

  attachInterrupt(digitalPinToInterrupt(DIGITAL_INPUT_SENSOR), onPulse, RISING);
  lastSend=millis();
}

void presentation()
{
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo("Energy Meter", "1.0");

  // Register this device as power sensor
  present(WATT_CHILD_ID, S_POWER);
  present(KWH_CHILD_ID, S_POWER);
  present(PC_CHILD_ID, S_CUSTOM);
}

void loop()
{
  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
    if (!SLEEP_MODE && watt != oldWatt) {
      // Check that we dont get unresonable large watt value.
      // could hapen when long wraps or false interrupt triggered
      if (watt<((unsigned long)MAX_WATT)) {
        send(wattMsg.set(watt));  // Send watt value to gw
      }
      Serial.print("Watt:");
      Serial.println(watt);
      oldWatt = watt;
    }

    // Pulse cout has changed
    if (pulseCount != oldPulseCount) {
      send(pcMsg.set(pulseCount));  // Send pulse count value to gw
      double kwh = ((double)pulseCount/((double)PULSE_FACTOR));
      oldPulseCount = pulseCount;
      if (kwh != oldKwh) {
        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
    request(PC_CHILD_ID, V_VAR1);
    lastSend=now;
  }

  if (SLEEP_MODE) {
    sleep(SEND_FREQUENCY);
  }
}

void receive(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++;
}

Anyone got any ideas?
BTW. First i tried the original example sketch, unmodified, with the same result.

gohan

That's pretty much the same problem as I have

xydix

I think i solved this.
I don't know if it is a good solution.
Maybe it is possible to solve in the code?
I added a 0,1uf ceramic capacitor between DO and GND on the LM393.
Then i tuned the LM393 until i had it blink as expected.

I think, in my case the LED pulse from my meeter was to short, it gives a very short blink.
Anyway.
I tested it all day and it seems fine now.

gohan

Are you getting instant power measurements correct?

xydix

Yes. I guess.
I don't have anything to compare with but i think it is accurate.
I have a 1000blink/kwh
Example:
Node send state every 20 sec.
pulsecount: 8 pulses every 20 sec.
Instant power in W is about 1400W

8 pulses x 3 = pulses /minute =24
24 pulses x 60 min = pulses /hour = 1440.

Edit.
Now I get a new value every 20 sec, before I didn't get any value (W) from the node at all because it was too high. I only received pulse count and kWh earlier.

gohan

Besides the cap, what exactly did you do?

xydix

Nothing more.
I use the same arduino, haven't uploaded anything new to it since i tried it last time.

What I had to do was lower the sensitivity on the LM393 because at first the signal-LED glowed a bit but when i adjusted it to lower sensitivity and closed the door to get it totaly dark the led blinked exactly as the meeter.

I have it on a bredboard and connected the cap between GND and to pin 3 so it is connected close to the arduino but i guess it shouldn't matter.

Have you tried it?

gohan

I can't believe it, IT WORKS!!!!! I added the cap directly under the pins of the LM939 board. Thanks man!

💬 Power Meter Pulse Sensor

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