Arduino 220V AC wattmeter

[stofakiller]

Hi,

I have a lot of arduinos lying around and thinking on turning them into a poweroutlet ac wattmeter... I have googled a lot and there are several solutions... But have any of you made a "poweroutlet ac wattmeter" connected to a GW?

Regards
Jan

[axillent]

I made one. It is not just wattmeter, it is a 3 channel power switch with meter function per each channel

in general you have just two solution while you want to keep your arduino be isolated from AC line:

1. using special chip like ACS712
2. using current transformer

in both ways you will need analog inputs to measure related voltage and you will be able to calculate current based on analog read

[epierre]

@stofakiller there has been a (short) discussion yet but I've not had time to make it.

Also, the Emonlib for doing that is now included in the mysensors libs.

@axillent have you posted your wiring and sketch yet ?

[maglo18]

I don't have energy meter with blinking led that i'm interested too how to build watt meter?

[jocke4u]

I also have interest in building a AC watt meter and have been thinking of using a CT but maybe using a DIN module like this is better. Then getting the pulse and use the existing energy pulse sketch.

Do you think this DIN module is more accurate than a CT?

[stofakiller]

Hi,

I found module from DX that i want to try, i dont want to mess with 220v cables So i waiting for this one to come
http://www.dx.com/p/yqj010504-single-phase-ac-current-sensor-module-w-active-output-deep-blue-5a-294209#.VDOyK2d_t8E

They also have this item, but then you have to play with high voltage...
http://www.dx.com/p/single-phase-ac-voltage-sensor-module-deep-blue-346690#.VDPO5md_t8E

Regards,
Jan

[maglo18]

I was just thinking about something similar

[jocke4u]

@stofakiller said:

I found module from DX that i want to try, i dont want to mess with 220v cables So i waiting for this one to come
http://www.dx.com/p/yqj010504-single-phase-ac-current-sensor-module-w-active-output-deep-blue-5a-294209#.VDOyK2d_t8E

Hmm, how can you get the 230V cable into the transformer without mess with it
You need to get a split core CT that you can open without touching high voltage lines; something like this (the blue one)
http://openenergymonitor.org/emon/buildingblocks/ct-sensors-interface

[stofakiller]

Hi,

That im will try to work with I have seen the one in your post, and i hope the one from dx is the same, but i'll keep you posted

[AtomicGrog]

@jocke4u said:

@stofakiller said:

I found module from DX that i want to try, i dont want to mess with 220v cables So i waiting for this one to come
http://www.dx.com/p/yqj010504-single-phase-ac-current-sensor-module-w-active-output-deep-blue-5a-294209#.VDOyK2d_t8E

Hmm, how can you get the 230V cable into the transformer without mess with it
You need to get a split core CT that you can open without touching high voltage lines; something like this (the blue one)
http://openenergymonitor.org/emon/buildingblocks/ct-sensors-interface

You cant... not only that you need a single wire so you cant for example shove a 3 wire 'kettle lead' through it. Stick to the split core approach, same principle and easier to implement.

[MarkV]

@stofakiller said:

poweroutlet ac wattmeter

I'm also searching for something like this and it should be possible.
Look at the fibaro wall plug [(http://www.fibaro.com/en/the-fibaro-system/wall-plug)]

Thats exactly what i want aldo then for less money or a arduino based plug.

[daulagari]

Look at the fibaro wall plug
Thats exactly what i want aldo then for less money or a arduino based plug.

That is quite challenging goal!

If you do not mind the form size it should be possible and the component cost could be lower.

ZWave devices are quite expensive (is that the Zwave license?) but companies have the economies of scale so they can spread fixed cost over more units and get volume discount on components.

[epierre]

yes the zwave chip and license and dev kits are expensive and proprietary...

[daulagari]

yes the zwave chip and license and dev kits are expensive and proprietary...

Any idea what piece of the pricing is due to the zwave chip and license?
Is that in the order of 2, 5, 10 or 15 Euro/Dollar?

On implementing it using MySensors: As this is 230/110 Volts, I think a housing is essential. In that sense I think I would start buying a cheap energy/watt meter from Ebay, opening it and replace the electronics by your own electronics.

[MarkV]

Okay
But isn't possible to make a similar device without the z-wave but with a arduino.
instead of pussing the signals to a z-wave chip, push them to a arduino??
Just a simple voltage en current measuring device and let the arduino calculate and store the wattage or kWh...
That would be a nice and cheap sollution..

[daulagari]

If you want something simple, see http://gizmosnack.blogspot.se/2014/11/power-plug-energy-meter-now-wireless.html.

[Dean]

@axillent looks like there are a few people like me who are interested in your set up... Would you mind sharing more details one what you did, actual hardware setup, sketch, issues, etc?

[mainali]

@axillent said:

I made one. It is not just wattmeter, it is a 3 channel power switch with meter function per each channel

in general you have just two solution while you want to keep your arduino be isolated from AC line:

1. using special chip like ACS712

in both ways you will need analog inputs to measure related voltage and you will be able to calculate current based on analog read

I have tried using ACS712 to check if current is passing through the circuit, from the sketch I am using, sometimes even though the switch is off I get readings, Is there a way to make it full proof so that if there is no current there should not be false reading.

Do you have any sketch related to the implementation?

[Vladut Grecu]

When you implement it with your relay you can call the readings only when the relay is on. That way you get accurate measures and don`t overload the mcu

[mainali]

I have a relay connected to a two way switch, I want to know when the switch was pressed. Basically I want to control the device via both the switch and the app which controls the relay. In case someone switches on the device from physical switch I want to update the app to show that the device is switched on. Hence using the current sensor to sense the current between the switch.

[axillent]

false readings from acs712 is a subject of electrical noise
I also faced it
coper&wires from acs712 to MCU have to be as short as possible