💬 Power Meter Pulse Sensor

mickecarlsson

Here is a code example that works for me. I have an energy meter with S0 output and I use Domoticz as the controller.

/**
 * 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
 * Version 1.1 - Mikael Carlsson
 *
 * DESCRIPTION
 * This sketch provides an example how to implement a sensor reading from an energy meter
 * 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

#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 meter
#define SLEEP_MODE false        // Watt-value can only be reported when sleep mode is false.
#define MAX_WATT 10000          // Max watt value to report. This filters bad data.
#define CHILD_ID 1              // Id of the sensor child

unsigned long SEND_FREQUENCY =
    20000; // Minimum time between send (in milliseconds). We don't want 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(CHILD_ID,V_WATT);
MyMessage kwhMsg(CHILD_ID,V_KWH);
MyMessage pcMsg(CHILD_ID,V_VAR1);


void setup()
{
    // Fetch last known pulse count value from gw
    request(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(CHILD_ID, S_POWER);
}

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 happen when long wraps or false interrupt triggered
            // We need to send in all values at one time to get consistent data
            if (watt<((unsigned long)MAX_WATT)) {
                send(wattMsg.set(watt));  // Send watt value to gw
                Serial.print("Watt: ");
                Serial.println(watt);
                oldWatt = watt;
                send(pcMsg.set(pulseCount));  // Send pulse count value to gw
                Serial.print("pulseCount: ");
                Serial.println(watt);
                double kwh = ((double)pulseCount/((double)PULSE_FACTOR));
                oldPulseCount = pulseCount;
                send(kwhMsg.set(kwh, 4));  // Send kwh value to gw
                Serial.print("kWh: ");
                Serial.println(kwh);
                oldKwh = kwh;
            }
        }
        lastSend = now;
    } else if (sendTime && !pcReceived) {
        // No count received. Try requesting it again
        request(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++;
}```

dakipro

One (probably stupid) question about the batter powered option: Since sensor cannot keep track of real time power usage as it sleeps most of the time, would it be possible to do the math on the controller side and get "5min delay real time power usage"?
By dividing number of pulses since last transmission, is that basically what this sensor is doing when not being powered by batteries?

I could experiment with 2min delay f.eks, and see how batteries hold. If dht22 temp sensors works over a year with 5min transmission time, i hope 2min delay in pulse meter can hold 6mnt or something?
Another thing is that the electrical box is all metal, and there is a lot of electricity around the sensor so radio could struggle (I guess a repeater would definitively help)

gohan

Is it only me that is getting a compile error?

Error: call of overloaded 'set(volatile long unsigned int&)' is ambiguous
send(wattMsg.set(watt)); \ Send watt value to gw

error: call of overloaded 'set(volatile long unsigned int&)' is ambiguous
send(pcMsg.set(pulseCount)); \ Send pulse count value to gw

followed by all the possible candidates of .set arguments

mfalkvidd

@gohan I get the same, both for 2.1.1 and 2.2.0-beta. Strange. I thought there were Jenkins tests that endured the examples compiled.

mfalkvidd

Replacing all

unsigned long

with

uint32_t

makes the sketch compile fine, but I don't know if that is the correct solution.

mfalkvidd

I created an issue for this, https://github.com/mysensors/MySensors/issues/910

hek

The problem with "unsigned long" is that it can have different size based on platform it's compiled on.

Like @mfalkvidd says, use int32_t, uint32_t, int16_t and uint16_t which has a fixed width.

gohan

I was suspecting something like that, but I was not sure if changing variable type would affect something else

gohan

Ok, I got it working. On wemos it doesn't count pulses though. On domoticz does it have to configured as the value computed or from device? I'm asking because if you disconnect the sensor, on domoticz I keep seeing the same power reading

gohan

BTW, is there a way to have the pulse meter running on gateway? I got stuck because at startup it asks the controller the last count value and since the controller is not yet connected it just doesn't work.

arifuleee

@gohan for the first time use only the watt value....that time oldcounts will not bother.....

gohan

What do you mean? And how do I keep the count of the pulses if I don't get it from controller?

gohan

@hek is it me or the WATT readings are never sent? What could it be? Only V_VAR1 and V_KWH are sent.

rejoe2

@gohan How about

#define MY_TRANSPORT_WAIT_READY_MS 2000

This will start up your code so you won't miss any pulses until controller is ready.
You may ask for the last known Value in presentation(), then it will be fetched as soon as the controller is really there after startup. This could/should be combined with a bool pcReceived, so you may decide to either add the value received from controller to the counts the node meassured in between or just use the received value (starting from second time value is received from controller).

gohan

That actually is not that critical, as I am going to move to MQTT and that should be working anyway. Right now it is working on a UNO with NRF24, but my biggest issue is the WATT reading that it is missing

gohan

Any more suggestions on the Watt issue?

hek

Did you by any chance change SLEEP_MODE to true?

gohan

No, I get every pulse reported as soon as it is detected.

gohan

I think I found a problem: the WATT calculation is returning values over 172000 watts and since I put 10000 as the max value, it was not sending anything. I double checked my energy meter and indeed it is 1000 pulses per KWH and this is what I set in sketch

gohan

@hek I said I found the problem, I didn't say I know how to solve it 😅

💬 Power Meter Pulse Sensor

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