Read smart meters (SML interface) with ESP and Tasmota and send data to emoncms


I recently stumbled across a very nice readout head for smart meters that can send data directly via wifi with an ESP running Tasmota:

Tasmota offers a smart meter interface for this purpose, which in combination with scripts allows the connection of almost any smart meter: Smart Meter Interface - Tasmota

In my case, I can use it to read out the total grid consumption, feed-in and the current power, but it depends on the individual smart meter, which data are accessible via SML interface.

The Scripting Language of Tasmota (Scripting Language - Tasmota) makes it super easy to process the data and send it to any web server. Here is an example to send the data directly to an emoncms instance ( works too).


=>sensor53 r


if upsecs%10==0
and *sml[1]* != 0


=>WebSend %url%/input/post?node=SML&fulljson={"Power":%sml[3]%,"Grid":%sml[1]%,"Feedin":%sml[2]%}&apikey=%key%

>M 1

Just add your apikey and the suitable script part for your smart meter, that’s it.

@TrystanLea and @glyn.hudson Maybe this would be a nice addition to your webshop? Smart meters are steadily spreading and the beauty of it is that it all works without any work on the electrical system.

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Actually, you are reading the LED Pulse that was available long before smart meters, so it really has nothing to do with Smart Metering. I’ll edit the title so as not to confuse.

There is a pulse reader in the shop, but that requires a separate device to detect the pulse. This does look like a good solution! Thanks.

Perhaps I misunderstood, does this device have builtin Wi-Fi/ESP chip?

Have you a link to it?

It’s not about reading out the LED, I know the article from the store, have also tested it myself. The read/write head uses the infrared interface which speaks either SML or OBIS. So the actual meter and power values are transmitted instead of the pulses.

Here is a link to the webshop:

I think it`s a really fancy device for just 34 €.
Could be a nice addition to the OpenEnergyMeter product portfolio, in my opinion.

In the UK?

I suspect this is for European meters. AFAIK UK meters do not have an IR interface but use encrypted Zigbee for the HAN.

I believe some do have an IR interface, but it too is encrypted (presumably so that the meter owner can charge you to get your own data back via their website. :roll_eyes:)

An easy way to feed UK smart meter data into emoncms is to use the Glowmarkt Display and CAD . It connects to a SMETS2 or SMETS1 smart meter using Zigbee and can be configured to push the data over Wi-Fi using MQTT. I use nodered to re-format the data for emoncms so I can display both the import and export meter readings with a resolution of 1wH as well as getting a real time power feed. They also have a smartphone app and APIs which allow you to pull historic data from their web site

Yes, I do exactly the same.

Nice find @Simsala! and thanks for sharing how to do this. Wow looks like quite a long list of supported meters on there, definitely one for us to look into in more detail.