Using a S0 port from a kWh meter

[Mediacj]

Is there a way to use the S0 port of a kWh meter within Espeasy?

I don't mean the led pulses but the real port of some kWh meters which is actual not more then a pulse switch.

I found interesting information here:
http://fun-tech.se/FunTechHouse/ElectricityMeter/

I tried to use that scheme on the pulsecounter module within Espeasy (without the real pulsecounter TCR5000) but direct to gnd vcc and gpio 0 but that gave to many pulses.

[rtenklooster]

I have no idea how these S0 port works, If you connect a led between those two pins, does it light up?
Or does it act like a switch? In that case I would indeed activate the internal pull-up in the device settings, and connect 1 port to gnd. the other to a GPIO port.
The pull-up is important te prevent false pulses.

You can always try it the other way: disable pull-up, connect to vcc and GPIO port, and from the same GPIO port a 10k resistor (pull-down) to ground.

Update:
just saw you updated your post, according to that schematic, it should work as described above (the second option) Disabling internal pull-up and adding a pull down resistor is crucial.

[Mediacj]

Thanks for your answer!

Yes it is a switch but every closed contact of the switch is the same as a led pulse on the kWh meter, so we are also counting energy.

Yes the second option works kind of but then I have to use the switch option within Espeasy and can't count energy as with the pulsecounter. But it works I see the switch turning on and off in almost the same rhythm of the led pulse

Is it possible to make a separate S0 pulsecounter with the pull up option of the switch and send it to Domoticz as a incremental counter just like the standard pulsecounter?

[rtenklooster]

You can just use the default pulse counter. In that case it's just working. Just replace the ldr with the s0 connection and it should work.

[Mediacj]

Yes you are right tried it before but without removing the original ldr, now without the ldr it seems to work fine

Thanks!

[Mediacj]

It would be nice to have the actual power(Watt) also in Domoticz beside the energy used/generated in kWh.

Just like this sketch from the Mysensors project:
http://www.mysensors.org/build/pulse_power

There is always something to wish for

[rtenklooster]

It would be nice to have the actual power(Watt) also in Domoticz beside the energy used/generated in kWh.

Just like this sketch from the Mysensors project:
http://www.mysensors.org/build/pulse_power

There is always something to wish for

I Started a new thread requesting some extra functionality so we can add this functionality.
if everyone responds to this topic to let know i'm not the only one... maybe it will be added to domoticz, so we can add it to our esp sketch.
https://www.domoticz.com/forum/viewtopi ... =28&t=8034

Currently i'm working on a new custom pulse counter that's not using interrupts, because for some reasons interrupts are occurring while the input pin stays high. E.g. when the mirror of my gas meter holds right before my TCRT, it generates some pulses where my old arduino sketch just did worked properly.

[Mediacj]

Great!

I have the same problem with my solar panels when there is no more production my S0 pulsecounter stays HIGH which makes it unreliable. Would be nice to see it fixed in combination with actual power

[beic]

You can just use the default pulse counter. In that case it's just working. Just replace the ldr with the s0 connection and it should work.

Hi rtenklooster,

What LDR and from what module?

Kind regards

[Ton_vN]

The S0-interface in a kWh-meter is an Open Collector type transistor-interface.
You need a pull-up resistor to VCC to get a signal which can be counted by the ESP8266, but that introduces 2 points of attention:
1) at the side of the kWh-meter sometimes for reliable operation of the S0-interface a voltage range is defined, which is beyond the range which is safe for the ESP8266!
2) at the ESP-side you must have a careful look which ESP-pin you choose as counter-interface (because of the pull-up resistor in combination with 1) !
Other aspect needing attention for interface-handling, is that usually an S0-interface has 1000 pulses/kWh, but types exist which have upto 3200 pulses/kWh, or < 1000 pulses/kWh.
That last aspect is especially important if you want to derive actual power (expressed in W) from the counted pulses (which are Wh):
not difficult, but you have to know how many pulses/second are equivalent to 1W.

[joshi]

Other aspect needing attention for interface-handling, is that usually an S0-interface has 1000 pulses/kWh, but types exist which have upto 3200 pulses/kWh, or < 1000 pulses/kWh.
That last aspect is especially important if you want to derive actual power (expressed in W) from the counted pulses (which are Wh):
not difficult, but you have to know how many pulses/second are equivalent to 1W.

For a device with 1000 pulses/kWh, you simply will not have pulses/second for 1 W, but rather one pulse per six minutes for 10 W. Even with a meter that produces 3200 pulses/kWh, you will have approx. one pulse in 2 minutes for 10 W. So don't expect a better resolution than that ...

[beic]

The S0-interface in a kWh-meter is an Open Collector type transistor-interface.
You need a pull-up resistor to VCC to get a signal which can be counted by the ESP8266, but that introduces 2 points of attention:
1) at the side of the kWh-meter sometimes for reliable operation of the S0-interface a voltage range is defined, which is beyond the range which is safe for the ESP8266!
2) at the ESP-side you must have a careful look which ESP-pin you choose as counter-interface (because of the pull-up resistor in combination with 1) !
Other aspect needing attention for interface-handling, is that usually an S0-interface has 1000 pulses/kWh, but types exist which have upto 3200 pulses/kWh, or < 1000 pulses/kWh.
That last aspect is especially important if you want to derive actual power (expressed in W) from the counted pulses (which are Wh):
not difficult, but you have to know how many pulses/second are equivalent to 1W.

Thank you for your nice explanation!

I made this circuit, based on someone's work, but not working on the ESP-01 attached to the GPIO-2, at the boot the BLUE led stuck's!

My kWh Meter is not the same as on the image bellow, I have this one, second model on the picture in the PDF file.
http://mixvill.com/data/docs/1382966107 ... eb_ENG.pdf




All resistors are 10k

But, if I put a transistor based inverter in font of that resistor divider it works, sending data to the ESPEasy Pulse counter without any issue, but I don't know that the received values are correct!


Can you maybe help me a little bit more?

Thanks again!

Regards

[joshi]

@beic:
I have a similar meter (not the same, but similar). In my case, the following setup works:
S- connected to ESP12E gnd
S+ connected to GPIO04 of ESP (other GPIO pins should work as well)
S+ also connected with a pullup resistor (10k) to Vcc of ESP

I am using the counter of ESPEasy. No need for an additional transistor and resistors.

[beic]

@beic:
I have a similar meter (not the same, but similar). In my case, the following setup works:
S- connected to ESP12E gnd
S+ connected to GPIO04 of ESP (other GPIO pins should work as well)
S+ also connected with a pullup resistor (10k) to Vcc of ESP

I am using the counter of ESPEasy. No need for an additional transistor and resistors.

It's working!!!

Are you using some kind of formula in the ESPEasy to send correct data to the Domoticz or?!

And thank you so much for your help!

[joshi]

@beic:
I have a similar meter (not the same, but similar). In my case, the following setup works:
S- connected to ESP12E gnd
S+ connected to GPIO04 of ESP (other GPIO pins should work as well)
S+ also connected with a pullup resistor (10k) to Vcc of ESP

I am using the counter of ESPEasy. No need for an additional transistor and resistors.

It's working!!!
Congratulations !

Are you using some kind of formula in the ESPEasy to send correct data to the Domoticz or?!

And thank you so much for your help!

I am just using plain counters in EspEasy and Domoticz and do all required calculations with a lua script in Domoticz - much more flexibility.

[hulzer]

I am just using plain counters in EspEasy and Domoticz and do all required calculations with a lua script in Domoticz - much more flexibility.

Could you explain what you calculate in your script?
Do you just use the "count" value? What about the "duration" setting in EspEasy - how is this value taken into account?

Thanks.

[beic]

I am just using plain counters in EspEasy and Domoticz and do all required calculations with a lua script in Domoticz - much more flexibility.

Could you explain what you calculate in your script?
Do you just use the "count" value? What about the "duration" setting in EspEasy - how is this value taken into account?

Thanks.

Yes, it would be really cool if you share your LUA script for the Domoticz and some explanation for it!

[joshi]

I am just using plain counters in EspEasy and Domoticz and do all required calculations with a lua script in Domoticz - much more flexibility.

Could you explain what you calculate in your script?
Do you just use the "count" value? What about the "duration" setting in EspEasy - how is this value taken into account?

Thanks.

Just the count. Esp sends the count every 360 seconds = 6 minutes. So one tick during 6 minutes gives me an average of 10 W during that period. That' s accurate enough for me.

[beic]

The S0-interface in a kWh-meter is an Open Collector type transistor-interface.
You need a pull-up resistor to VCC to get a signal which can be counted by the ESP8266, but that introduces 2 points of attention:
1) at the side of the kWh-meter sometimes for reliable operation of the S0-interface a voltage range is defined, which is beyond the range which is safe for the ESP8266!
2) at the ESP-side you must have a careful look which ESP-pin you choose as counter-interface (because of the pull-up resistor in combination with 1) !
Other aspect needing attention for interface-handling, is that usually an S0-interface has 1000 pulses/kWh, but types exist which have upto 3200 pulses/kWh, or < 1000 pulses/kWh.
That last aspect is especially important if you want to derive actual power (expressed in W) from the counted pulses (which are Wh):
not difficult, but you have to know how many pulses/second are equivalent to 1W.

Thank you!

My kWh Meter has 2000 pulse/kWh.

[beic]

Just the count. Esp sends the count every 360 seconds = 6 minutes. So one tick during 6 minutes gives me an average of 10 W during that period. That' s accurate enough for me.

Thanks, so, what Virtual Sensor you are using for it in the Domoticz?

[Ton_vN]

Saia Burgess issued a very clear Application Note on the layout & use of S0-interface.
If you give Google the following search-input:
s0 interface application
then somewhere in the resulting list you will find
Application instructions energy meter Topic: S0-pulse interface

[beic]

Saia Burgess issued a very clear Application Note on the layout & use of S0-interface.
If you give Google the following search-input:
s0 interface application
then somewhere in the resulting list you will find
Application instructions energy meter Topic: S0-pulse interface

I found it!

Thank you!

[ILoveIOT]

I'm fairly new to pulse meeting, I found a nice meter (Eastron SDM230-Pulse) but will it work with ESPEasy ? Or are there better options ? Looking for a cheap and stable solution for the whole house, I'am always using a minimum of 0.1KWH so I guess the resolution of 1000/1KWH is good enough.

https://nl.aliexpress.com/item/SDM220-P ... Title=true

I know the Sonos version, but I guess with 16A it has not long life span, also the RS485 with USB on Domoticz is not an option for me.

[Ton_vN]

Why a 'heavy' 100A&MID SDM230?
Type SDM120C perhaps sufficient for lower load and non-MID?
Application of the S0-interface should not be difficult if you configure a port of the ESP8266 as a counter.
Comparable meter Type DDS238-1ZN also available at AliExpress.

Why RS485-interface & Domoticz not an option?
Generally more accurate.
Domoticz (at the Forum) has ready-solutions for both SDM120C and DDS238-1ZN.

[ILoveIOT]

Why a 'heavy' 100A&MID SDM230?

Sounds stupid but the LCD readings are then normal horizontal to read, instead of vertically, don't mind the extra 10$, also it has a dual pulse port, I guess the accuracy of all these devices are the same.

Why RS485-interface & Domoticz not an option?

Its quite a distance between the KWH meter and the Orange PI (Domoticz), also USB connections for IoT (all the time) are "not done" for me anymore, should be all network based, or hard wired, would be nice to buy a cheap RJ45 LAN KWH meter, but they are quite expensive.

I saw also a option to use it directly on the GPIO ports on the Orange PI, maybe I can check that possibility otherwise I use the ESPEasy solution.
https://gathering.tweakers.net/forum/li ... es/1607839 (dutch)

Thank you for the info, normally I would buy it, and then ask questions

[Ton_vN]

Implementation as described in the Tweakers-link is similar to using ESP8266 as pulse-counter.
In line with your argumentation would then prefer ESP8266 connected to the S0-interface of the kWh-meter, and in your case for SDM230 then the pulse-output with highest rate/kWh to get the best resolution. From pulse-count to Energy is a simple, periodic accumulation/multiplication.

RS485-application is possible with long cable-length, but obviously you must then allow a cable running between the meter and the related processor, and that processor must have an RS485-interface with related software, as well as a script to handle the conversion & upload towards Domoticz, etc..

[ILoveIOT]

RS485-application is possible with long cable-length

I've already a RS485 bus for the moveable camera's and indeed that cable is long > 50M, so that should not be a problem, don't know how stable this solution is because you already mansion, the signal will take a long route, by the USB conversion and scripts, I got a spare USB port on the Orange PI, hmz.

I guess I will buy the SDM230 with RS485, ok its more expensive but only have to buy it once, and still have all the options, RS485 and dual S0, with nice readings.
(ps did not know about this (rs485) version somehow)
https://nl.aliexpress.com/item/SDM220-M ... Title=true

So the remaining question is, how more accurate is the RS485 compare to the S0 bus ? and maybe there is some more functionality, in domoticz ?
Try to google it but not getting a clear answer.

[Ton_vN]

The main advantage of a kWh-meter with RS485-interface is that the measurement of all parameters is realised immediately at the incoming 230V-interface, and this type of kWh-meters not only determines the actual power, but also other parameters like accumulated energy, voltage, current and frequency. Power and Energy are not only measured in 'forward' direction, but also in 'reverse' direction (like the Smart-meter for the public 230V-grid).
The S0-interface only produces a string of pulses per Wh in 'forward' direction, and the processor handling the interface from that pulse-string must calculate the energy-values by accumulation, and as second derivative a 'reconstruction' of the actual power by simple formula of (power) = (energy-in-period)/(time-period)
The RS485-interface is superior in the perspective that it is a real data-interface, with the Modbus-protocol including a CRC-mechanism.
Related to the measurement of energy both interfaces should be equal in effective resolution and quality.
Advantage of a kWh-meter with RS485-interface is also that the energy-measurement and energy-registration is continuously running and result is always available, ready for (later) read-out at the interface.
If you do not read an S0-interface, the pulses disappear in the 'black hole' and you only will know the energy-values by manually reading the display of the kWh-meter.

However, the implementation of a function handling an S0-interface is generally much simpler than for an RS485-interface, and examples are abundant.
In the Domoticz-forum the following threads and sections may provide some insight on the work to be done for implementation of an ModBus/RTU @ RS485-interface, if a software for a specific kWh-meter is not readily available:
- discussion of a 'general' Modbus-implementation
- a very compact implementation-solution for a kWh-meter type SDM120C (which type may be very similar to the SDM230 which you have in mind, but that can only be confirmed if you can get hold of the description of the interface protocol). The applicable protocol may be similar to this document.
- the development of an interface for kWh-meter type DDS238-1ZN

'Translating' such RS485-functionality into a practical & compact solution for an ESP8266/ESPEasy seems (at least) a challenge.
But perhaps I underestimate the skills & enthousiasm of the members of this Forum .......

[ILoveIOT]

Ok you've convinced me, and put my own promises aside and go for the RS485 route,...lol wrong forum but if I fail in it, (cannot imagine it use Linux now for 19 years) I still can use the S0 option with ESPEasy.

Thank you for the clear explanation, I would bought the wrong meter, and now for a few bucks more, the right meter,...many thanks

Translating' such RS485-functionality into a practical & compact solution for an ESP8266/ESPEasy seems (at least) a challenge.

Hehe,..I guess so too, but as you can see, they already created a nice project out of nothing.

[Ton_vN]

@ILoveIOT

You could start with a 'reverse' approach:
first apply the S0-interface with a counter-interface/-software on ESP8266, until you sufficiently have developed/adapted/tested the interface for the RS485-interface.
Once the RS485-interface is up & running, the S0-interface is useful backup & redundancy for Energy-measurement [comparison is nice, and you never know if/when a network-failure hits you ....]

[ILoveIOT]

Hehe, ordered the meter yesterday, including the RS485 (CH340) usb dongle, now I only have to wait a "few" days but I was already looking for a good excuse too use a extra ESPEasy Nodemcu setup in my house, now I got only a ESPEasy Nodemcu in production in my mailbox outside

Off topic : Still looking for a nice sticker (Intel lookalike),..with the text,..ESPEasy inside 80Mhz/4MB etc

[Ton_vN]

RS485 may be the better way to read-out a kWh-meter, but almost every kWh-meter has an S0-interface 'inviting/challenging' to be used.

Have 5 kWh-meters with their S0-interfaces now linked to a K8055-board @ PC and to an S0PulseCountingModule @ Domoticz.
The K8055-board operates flawless for read-out of 2 S0-interfaces.
However, the read-out of these S0-interfaces by the S0PCM has some problems due to the combination of long cables, cable-trajectory and low signal-levels.
An ESP8266 near the kWh-meter(s) reading the S0-interface(s) probably will improve the behaviour and the data transfer to Domoticz.

[Ton_vN]

This thread triggered me to explore the following configuration around a PV-inverter which has no local display-panel and cooling only by natural flow.
A kWh-meter checks the 230V-AC-output from a PV-inverter:
a) connect the RS485-interface from the kWh-meter to the RS485-bus controlled by a Raspberry-with-Domoticz/Python
b) connect the S0-interface to an ESP8266 as backup, transmitting data, either to the same, or to another Raspberry-with-Domoticz

The ESP8266 at the same time also measures the temperature of the cooling air rising from that PV-inverter, and for forced ventilation in relation could control fans by a relais.
Fitting an OLED to the ESP8266 would provide a local display, filled by the calculations in the 'local' ESP8266. Additional data to be fed from e.g. Raspberry-with-Domoticz.

Considering a WemosD1-board, the hardware configuration could be a 'pile' consisting of Processorboard, Protoboard (to connect external wiring such as for a DS18B20-thermosensor and for a switch for display-selection), relais-board and OLED

Somebody already tested & proven such setup?