💬 Power Meter Pulse Sensor
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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 -
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:2.6010The 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. -
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. -
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 1400W8 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. -
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?
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It waswhat I thought too.
As I said earlier, when I tested this my conclusion was, short blink, almost a flash will counted as a pulse (kWh) but it does something wrong with the calculation of instant power usage.
A slower blink will correct this.
My meeter gives a very short blink. -
I tried to build something similar and it is working nicely, thanks for sharing the idea! However, I've noticed the light sensor (alone) consumes 1mA constantly which is quite a lot when used for a battery powered project. Even if I report to the controller once per hour (summing up the power consumption along the way), still the light sensor needs to be always on, meaning I'd probably need to replace batteries after a month or so. Is there any workaround or alternative sensor which I can use or am I doing something completely wrong? Thanks
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I tried to build something similar and it is working nicely, thanks for sharing the idea! However, I've noticed the light sensor (alone) consumes 1mA constantly which is quite a lot when used for a battery powered project. Even if I report to the controller once per hour (summing up the power consumption along the way), still the light sensor needs to be always on, meaning I'd probably need to replace batteries after a month or so. Is there any workaround or alternative sensor which I can use or am I doing something completely wrong? Thanks
@user2684 I had the same issue when I built this with a standalone atmega328p running on 2x AA's. I set it up with wake on interrupt from the It was constantly drawing 1.6mA to power the tsl257 to detect the flashes. My target was 1+ years on 2 x AA's. My solution to achieve this was to sleep for 125ms, wake up, send power to tsl257 to check light state (on/off), if it changed from previous reading then there was a pulse (well half pulse). By measuring every 125ms I can guarantee to capture fast pulses up to 14.4kW. (3600000/125)/2. It is 20kW max draw for residential in my country. Now:
Average mA Consumption Sleep 0.1
Average mA Consumption Wake 0.064516129
Average mA Consumption Transmit 0.002916667
Battery Life (2xAAs) = 1.7 years -
@user2684 I had the same issue when I built this with a standalone atmega328p running on 2x AA's. I set it up with wake on interrupt from the It was constantly drawing 1.6mA to power the tsl257 to detect the flashes. My target was 1+ years on 2 x AA's. My solution to achieve this was to sleep for 125ms, wake up, send power to tsl257 to check light state (on/off), if it changed from previous reading then there was a pulse (well half pulse). By measuring every 125ms I can guarantee to capture fast pulses up to 14.4kW. (3600000/125)/2. It is 20kW max draw for residential in my country. Now:
Average mA Consumption Sleep 0.1
Average mA Consumption Wake 0.064516129
Average mA Consumption Transmit 0.002916667
Battery Life (2xAAs) = 1.7 years@cstewy many thanks and very interesting. You basically saying it consumes less by waking up every 125ms rather than being asleep but with the sensor eating up current continuously. Definitely worth trying thanks! Meanwhile I've reduced the number of radio transmission and the batteries lasted for a couple of months but still is not ideal. Thanks! I'll try and report back
