Initial setup SlimmeLezer

The SlimmeLezer comes preconfigured with ESPHome, so it can added to Home Assistant quite easily.

The best way for setting it up, is to power it via an USB power supply. In some minor cases, when the SlimmeLezer starts broadcasting its own AP ‘slimmelezer’, it may draw a little too much power and can give problems during setup.

When it’s powered up, it broadcasts a wireless network ‘slimmelezer’. Be patience as this can take 20 to 40-ish seconds. Connect to that wireless network with a phone, tablet or laptop. Once connected, a captive portal will show after some seconds (10 seconds on my iPhone SE and 40 seconds on my iPhone 11 Pro). There you select your network and fill in the required password if needed. Note: hidden networks do work, yet needs an extra setting which isn’t set in my precompiled firmware: fast_connect: true).

When it takes too long to show the slash page, got with a browser to the ip-address

Once connected, it will auto discover in Home Assistant, where you can complete the integration.

If it doesn’t appears in the auto discovery, go to Add Integration > ESPHome:

That’s it, you’re all set to use the SlimmeLezer.


  1. HJoe

    i got my SlimmeLezer yesterday, thank you!
    Tried to set it up using the method above, but always got the error that “[E][dsmr:036]: Error: Message larger than buffer”, no matter how i tried to flash or configure it later. I have opened a ticket at ESP Home issue tracker (, but then I realized that it could be hardware related error as well.
    What do you think Marcel? Any suggestions are welcome.

    1. Marcel

      There are two things you can do:
      1) Stick to ESPHome and open an issue on ESPHome’s GitHub (I’m not the creator of the code, I’ve paid a developer to make it 😉 )
      2) Use esp-link, that’s another kind of firmware which spits out all incoming data via telnet. Than use DSMR integration instead of ESPHome. This could also be handy to give the developers some feed of your data to investigate what’s happening.

  2. Hjalmar

    Hi! Connected the slimmelezer to a powerbank and did the initial WiFi setup. It connected to my WiFi, but when I should connect it to the power meter by the cable it will not start (disconnected to powerbank first). The blue WiFi-led is just blinking once shortly when I put in the cable. Also if I connect the powerbank. How will I fix this?

  3. Florian

    I connected the Slimmelezer exactly like you wrote above. It also appears in the integration window however all the entities except IP address, Uptime, and some Wifi stuff write “Unknown”. The only thing I might have done wrong is that I forgot to update Homeassistant to the newest version, I did that right after connecting the Slimmelezer.

  4. Florian

    I just wrote the other comment. Just wanted to say, I tried installing the Slimmelezer using ESPhome and your code. Same thing, but it doesn’t say “invalid string length”, it says “Incomplete or malformed checksum”… No idea what to do. Btw my device is the “Sagemcom T210-D-r”. Thanks for your help!

      1. Florian

        First of all, thank you so much for your quick reply! I can only imagine how much you have to do right now… Unfortunately, the newest firmware doesn’t change anything. I updated it using esphome-flasher. I still get the same message in the debug log:
        [E][dsmr:138]: _�:2�6�$Sa��f�\:����[��*(�����@C�����g�’TM��
        Incomplete or malformed checksum

        No idea what thats supposed to mean…
        Before, I also tried putting in that extra code from PietPetrus, also no change…

          1. Martin

            Hello Marcel,

            i think i have the same problem (Incomplete or malformed checksum [E][dsmr:138]: [……). Today I have installed Version 2021.9.3 and the problem is still present.

            Nevertheless I am pretty sure, what the problem is. Since i first tried the SlimmeLezer, my power provider told me, that our Smart Meters are sending the Data AES256 encrypted.

            They provided me with the key to decrypt it but i have absolutely no idea how to do this. Is there a predetermined userexit in the firmware or do i have to decrypt it in hasio due to hardwarelimitations? Although the controller should be able to handle AES.

            Would be great if you have any information about this.

            Best Regards

          2. Floris

            I’ve used 2021.8.2 and it is working now.
            What is the difference with your latest firmware (2021.9.3)?

          3. Marcel

            Some bug fixes, I’ve placed now the latest 2021.10.3 on the product page with a checksum mismatch fix in it (telegrams where getting too large)

          4. B van Duijn

            Yes, assuming this is the “old” meter, delivered 2 months ago.

            Today I ran the update from the product page, “update success” now the device is offline with no wifi visible. Even when powered by usb.

            What to do?

  5. milan

    Hi Marcel,

    Ik ben een complete newbie wat betreft home automation. I heb Home Assistant draaien in Virtual Box in Linux Mint en kan verbinding maken met de UI via mijn browser. Nu heb ik gelezen dat vanaf DSMR5 de slimme meter van stroom wordt voorzien. Mijn meter is DSMR4 en mijn vraag is hoe ik op de slimme meter een voeding aansluit. Verder zou ik graag een uitgebreide handleiding willen ontvangen voor de rest van de installatie. Of links naar waar ik meer kan lezen hoe een en ander werkt en hoe te installeren en firmware updaten.
    Ik hoop dat je mij kunt helpen.

    1. Marcel

      De SlimmeLezer heeft aan de ene kant de opening voor de “telefoon” kabel en aan de ander kant een kleine opening waar de micro usb aansluiting zit. Daar sluit je een simpele telefoonlader, of een usb lader met een usb naar micro usb kabel. Alsof je een telefoon oplaad.

      Flashen kan via OTA. Als de meter een maal is aangesloten op je wifi, kan je naar het ip-adres gaan met een webbrowser en daar via OTA een nieuwe firmware uploaden. Als dat niet lukt, kan je ook via USB de firmware uploaden:

      1. Milan

        Oké ik heb ‘m van stroom voorzien maar ik zie niets verschijnen in mijn netwerk. Is 550 mA output van de adapter genoeg stroom of moet een zwaardere adapter gebruiken? Alle apparaten in mijn netwerk hebben als IP-adres. Hoe kan ik het IP-adres van de slimme lezer aanpassen? En moet ik de slimme lezer in home assistant toevoegen? Zo ja, hoe doe ik dat?

        1. Marcel

          Zie je wel een wifi netwerk erbij komen, genaamd ‘slimmelezer’? Jouw wifi gegevens zijn natuurlijk nog niet bekend in de firmware. Dus de eerste stap is om dat te koppelen aan je wifi.
          * Sluit de SlimmeLezer aan, bij voorkeur aan een usb-lader tijdens configuratie
          * De SlimmeLezer gaat na een seconde of 20~30 een wireless netwerk opzetten, genaamd ‘slimmelezer’
          * Maak daarmee verbinding, na een tijdje (10~60 seconde) komt er een captive portal waar je je wifi kan selecteren
          * Na je wifi credentials ingevuld te hebben, zal deze verbinden met je netwerk en stoppen met het broadcasten van ‘slimmelezer’
          Nu zou het klaar moeten zijn voor gebruik. Via je router moet je je ip kunnen vinden, kans is groot dat het ook bereikbaar is via slimmelezer.local (even pingen).

  6. Zsolt

    Dear Marcel,

    I just stumbled upon your little beast when searching for a possible interface device for my SmartMeter. I recently got my solar panels installed, and theoretically my meter has a P1 port (yet to find out if it’s true, since my provider installed a totally unneccessary extra front plate blocking the port, so I have to officially ask them to reveal the port itself).

    I’d love to buy your preassembled device, and saw that they are out of stock at the moment. Is there any chance to sign up for a “back on stock” alert, so I don’t have to come back every day twice to check if you have them again?
    Many many thanks, and keep up the great work you do!!

    Cheers from Hungary!

    1. Marcel

      I used to sell them as backorder… yet those backorders are growing instead of decreasing, therefor I’ve decided to wait until I’ve got them on stock again. Just keep a close watch on my website. You can subscribe for updates 😉

  7. Thw

    Hi Marcel,
    Mijn Slimmer Lezer is not showing gas consumption.
    I have flashed the slimmelezer with the 2.x firmware for my Iskra MT-382 meter.
    Electricity, both consumption and produced, is showing, but not the gas consumption.
    Is this a known issue?

      1. Thw

        Hi Marcel,
        Thanks for the swift reply. Could you be more specific about the period? It’s been up for more then 2 days now and still shows no gasconsumption. Is that normal?

        1. Marcel

          Het kan zijn dat de gasmeter op een andere BUS ID zit, daar kan ik je nu niet mee helpen. Er loopt een change om deze zelf in te kunnen stellen, maar dat is volgens mij ook alleen nog voor DSMR 4 en 5. Ik raad je aan om support te vragen bij Michiel Appelman op zijn GitHub.

          Het enige wat ik je als support kan aanbieden (en aanraden) is om esp-link te gebruiken in plaats van ESPHome. Dat kan je hier downloaden. In de download zit zit alles wat je nodig hebt, de firmware, hoe je het installeert etc. Hoe je esp-link aan je wifi koppelt, staat hier beschreven.

          De SlimmeLezer met esp-link koppel je via Integratie > DSMR aan je Home Assistant door het ip-adres van de SlimmeLezer en poort 23 in te vullen.

  8. Božidar Brozinčević

    Just recieved slimmelezer today!
    I have connected slimme with USB to do initial setup. It does connect to my wifi, and I was able to add it as integration to my HomeAssistant.
    Now when I disconnect it from usb and connect it to power meter with provided cable ( It’s AM550 it doesn’t show up. As I understand, slimme should work without aditional power?
    Any advice?

    1. Marcel

      Hi, yes indeed, it should. However I’ve seen some cases (can count it on 2 hands) that de DSMR 5 doesn’t give enough power. I’ve seen more cases that the port wasn’t enabled. Can you measure on the two outer pins if there’s 5 volt on it?

      1. Božidar Brozinčević

        Well, I didn’t measure power, but I tried to connect it with USB external power.
        I have only ip adress, signal strength and uptime.
        No measurement….
        Any aditional advice? What can I look for

          1. Božidar Brozinčević

            I have tested voltage on cable – 0V on outer 2 pins.
            I have tested cable, cable is OK.
            I fear that port is disabled…

    2. Boštjan

      Božidar, may I ask how old is your AM550 (which year of production?). I have the one from 2020 and it’s not working with Slimmelezer as it uses a different comm protocol as older ones (as one of electricity providers explained me, the Slimmemlezer can only communicate with AM550, which are 2017 or older).

      1. Marcel

        The SlimmeLezer is based on DSMR… If the meter uses another protocol, than we need to find out if we can add support fir that. I’d suggest to open an issue of feature request at ESPHome GitHub.

      2. Božidar Brozinčević

        Don’t know what year production was, I just got it recently (year ago). Ill take a look tommorow when I get home

        1. Mo

          Hi Božidar,

          Did you manage to check the P1 port? Did you get it activated?
          I have the same problem with my meter. It’s AM550 (2020), SMR 5.0
          Connecting to the P1 port gives no power but USB is fine.
          Can’t have a USB power adapter in my meter closet as there is no power and no USB ports on this meter.

    3. Piotr Kiełczewski

      Last week I tried to run SlimmeLezer in connection to ISKRA AM550 from year 2020 (installed in Poland) and also have only WiFi and Uptime information, no measurement values (Unknow).
      SlimmeLezer is correctly powered via P1 port of AM550, so I assume that P1 is enabled (is that right?)
      It’s really bad news if the ISKRA AM550 from 2020 have different coomunication protocol, that isn’t supported by the SlimmeLezer 🙁 I hope that this is only software issue and new firmware will solve this incompatibility, but when we can expect it?
      I’m not very familiar with ESPHome, DSMR, GitHub, etc., so I have no idea if I could do something else in my own to solve this issue. Any advice?

      1. Marcel

        That’s a pity to read 🙁 You should open an issue at the ESPHome GitHub, as they’re maintaining the code/source. If that doesn’t work, you can always try to use esp-link and integrate via DSMR (ip of device and port 23).

  9. Didier Rummens

    Hello, same problem as Florian, everything ok but except Ip, SSID, uptime all the other entities are “unknown”…
    Any idea ?
    I’m running HS 2.8.8

          1. Didier

            Hello again,
            I flash with the Firmware: 2021.8.2 (Sep 11 2021, 20:36:43) (slimmelezer-2021.8.2-state_class-and-BE-fix.bin as I live in BE) but still the same problem in HA: value “unknown” and in the log of the Slimmelezer Web Server I see this:
            [E][dsmr:138]: 0-0:96.1.4(202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020202020)
            Invalid string length

            Thanks for your help

          2. Marcel

            That’s really awkward! 0-0:96.1.4 is the P1 version. That should be like (50213) or something like that. I really advice you to use your own esphome add-on and your own config in HA. You can leave this field away and workaround this issue.

  10. Leo

    Hi Marcel!
    I just got the slimmelezer. Thanks for all your hard work!
    Eager to try I fired it up connected to usb-power but not to the meter. I then get it to connect to my wifi and I am able to access the page with all the information (of course empty).
    When I then try to connect it to my meter I can only connect to the slimmelezer AP. It doesn’t seem to want to start up properly. I tried uploading the latest firmware, and it was successful, but it made no difference. It should have sufficient wifi access outside, and my SSID appears in the initial page.

    Could there be an issue with my meter? It is a Sagemcom T211.

    1. Leo

      Never mind me! It does work, it was probably just the signal strength to the wifi that was a bit to bad, but enough to access.

      Moving it out of the box outside solved it and I get proper data 🙂

  11. Sander van den Broek

    Aansluiten ging eenvoudig, integratie met Home Assistant idem. Echter, in HA wordt er geen data getoond. De waarden van alle entiteiten staan op ‘onbekend’. Wat gaat er mis?

      1. Sander van den Broek

        Euh, geen idee. Hoe kan ik erachter komen?

        Meter is 7 jaar geleden geplaatst met de zonnepanelen. Data werd via P1 uitgelezen naar Enelogic.

        1. Marcel

          Ik zal je een mailtje sturen, kan je daarop antwoorden met een foto van de meter. Zal kijken of ik wat meer voor je kan vinden.

  12. Patric Falinder

    I’ve added my SlimmeLezer to Home Assistant Core and it went fine but when I try to add it to the new Energy-function in HA I just get “No matching statistics found”. What do I need to do to be able to get SlimmeLezer working with HA Energy?

    1. Marcel

      Could be you’re using older firmware… Do you built your own firmware within esphome? Did you try the latest firmware on the productpage?

      1. Patric Falinder

        I run the default config. I flashed Firmware: 2021.8.2 from the product page but now I noticed that there was a “state_class fix” which fixed the problem with HA Energy so now I can choose the SlimmeLezer in the Energy config.

        However now I have another problem. At first I could see all the values from the web UI, even after I flashed the first firmware but a day later when I checked everything is blank except Uptime, Wi-Fi Signal, IP Address and Wi-Fi SSID. I just flashed the state_class fix and it fixed the HA problem but the values are still bland.

        I see there is one comment below me with the same problem. I also live in Sweden. Do you know what the problem might be?

          1. Patric Falinder

            I have a Landis & Gyr E360 which supoorts DSMR 5 if I understand correctly.
            The first time I starten it all the values showed up but when I checked the day after all the values where empty.

      2. Patric Falinder

        No just uptime and wifi signal:

        [D][sensor:131]: ‘Uptime’: Sending state 1131839.37500 s with 0 decimals of accuracy
        [D][sensor:131]: ‘Wi-Fi Signal’: Sending state -62.00000 dBm with 0 decimals of accuracy

          1. Bubi

            Dear Marcel,

            as a lot of users written above, there are countries/energy providers, where Slimmelezer does not work. You always do your best when you suggest to use esplink, I did it – but the problem still persists. Homeassistant DSMR module does the same as your firmware : it cannot handle the telegram’s last line, OBIS 0-0:96.13.0 because it contains non-ascii characters.
            Github issues opened months ago, there’s no answer from the developers of esphome, not the dsmr integration.
            So, please build a list with _working_ powermeters/countries (your buyers will help) to avoid disappointed buyers.

            Here’s the first one : Hungary, e-On, Sanxing SX631 does NOT work with slimmelezer.

        1. Hannes

          Hej Patrik!
          Jag har samma problem som dig nu, med samma elmätare.

          Fick du ordning på problemet och hur gjorde du isf?

      3. Patric Falinder

        I have just installed esp-link on my device and plugged it in to my meter.
        Where and what am I suppose to see?
        When I check “Debug log” I pretty much just see a bunch of HTTP GET requests.
        When I check “μC Console” it’s empty.

        Does this mean my electricity company stopped announcing data on the HAN-port? Or do I need to make any changes to the settings?
        It gets power through the HAN-port so it can’t be deactivated, right?

        1. Patric Falinder

          I just got back from my electricity provider and they said that there is a bug in the Landis & Gyr E360 that can disable the port apparently. Landis have a solution in the works but they didn’t know when it will be available yet.
          He said I could try to cut the power and wait for 2 minutes and see if it will work again but even if it does it can get disabled again until the bug is fixed.

          This might save some headache for someone else that has the same meter.

  13. Martin Granlund

    My friend and I having trouble getting data to the device from the meter. All fields are blank in the webserver except some basic wifi info, and no errors in the debug.
    We both have a kamstrup omnipower 3 phase meter with a HAN-module (P1) (sweden)
    Have tried all the firmware and double checked that the p1 port is open from the provider.
    I have all the datasheets if you want to check them out, not sure what to do here.

  14. Papaya


    Belgian user here with a Sagemcom T211 (so, tri-phases) managed by ORES. I’m running the SlimmeLezer with firmware 2021.9.1 and have added the fix for Belgium:
    lib_deps: glmnet/Dsmr@0.5
    lib_ignore: glmnet/Dsmr@0.3

    Though, I notice that the voltage (and the power) on phase 2 is never read. The current is working on phase 2 (and varies), but nothing for the power and the voltage.
    For the other phases and the other sensors, it all works fine (except the total consumption which does not take into account the phase 2 as well).

    Is it a firmware problem ? (I did not find anyone reporting such issue) Or an hardware problem ? (but it would be strange if all other sensors are OK)

    But then, like this, I cannot add it into my Home Assistant’s energy board as the results are not consistent.

  15. Gino Watteny

    Integratie ging vlot, echter staan alle waarden op “onbekend”
    Wifi en ip krijg ik wel , echter niks van de meter…
    Moet ik nog extra configuratie toevoegen na de installatie?
    Moet ikde dsmr integratie toevoegen ,of zou hij zo out off te box moeten werken?

    1. Marcel

      Er zijn wat issues (weet niet of deze inmiddels opgelost zijn) met DSMR 5 en Belgische meters (nieuwere firmware). Als je nu de laatste ESPHome gebruikt en met de yaml code de firmware zelf maakt, zou het sowieso opgelost moeten zijn (dacht ik zo uit mijn hoofd). Als dat niet het geval is, kan je altijd esp-link gebruiken en integreren via de DSMR integratie (ip van de slimmelezer en port 23).

      1. Gino

        Hey Marcel , bedankt voor de reply. Echter geraak ik er niet uit…
        Even de onduidelijke zaken:
        -De laatste firmware : in de esp home zie ik bij firmware 2021.9.0 staan. Is dit de laatste?
        -De yaml code gebruiken om de firmware zelf te schrijven: hoe begin ik hieraan? Complete leek hier op gebied van programmeren… Waar voeg ik de code toe? Gewoon in de configuratie van home assistant of ergens anders?

        1. Marcel

          Op zich is het niet moeilijk. Binnen Home Assistant kan je een ESPHome add-on installeren. Eenmaal geïnstalleerd, kan je een device toevoegen, dat doe je met de yaml file. Eenmaal toegevoegd, kan je dat wijzigen naar je eigen wens (sensoren die je niet gebruikt weg laten, eigen wifi credentials toevoegen etc.). Dat kan je vervolgens exporteren als bin-file en uploaden naar de SlimmeLezer.
          Als dat net even te ver gaat, kan je ervoor kiezen om esp-link erop te zetten (dit is vrij eenvoudig en kan ik je doorheen praten/mailen).
          Laatste optie is om te wachten tot het door ESPHome is opgelost (ik raad esp-link nu aan).

      2. Gino Watteny

        Hey Marcel ,
        Even wat geprobeerd en het is gelukt om de firmware 2021.8.2 te flashen. Nu werkt het perfect , enkel geen voltage reading op phase 2 , maar dat deert mij niet. Ik zie mijn piekuur verbruik , mijn daluur verbruik en mijn gas. Dat is wat ik wou , dus TOP.

  16. Rogier

    Hoi! Net aangekoppeld aan mijn nieuwe DSMR5 meter.. krijg ik de onderstaande meldingen te zien via de webserver (en het loopt maar door)

    Enig idee wat ik kan doen om het te verhelpen?

    [E][dsmr:137]: 0-1:24.2.1(700101010000W)(00000000)
    Missing unit
    [E][dsmr:137]: !73A0
    Checksum mismatch
    [E][dsmr:137]: 0-1:24.2.1(700101010000W)(00000000)
    Missing unit
    [E][dsmr:137]: !13E6
    Checksum mismatch
    [E][dsmr:137]: !4E68
    Checksum mismatch
    [E][dsmr:137]: !6A23
    Checksum mismatch
    [E][dsmr:137]: 0-1:24.2.1(700101010000W)(00000000)
    Missing unit
    [E][dsmr:137]: 0-1:24.2.1(700101010000W)(00000000)
    Missing unit
    [E][dsmr:137]: 0-1:24.2.1(700101010000W)(00000000)
    Missing unit

  17. Rene vd Linden

    Ik heb net mijn slimmermeter binnen en aangesloten.
    Integratie in HA gaat goed.
    Wanneer ik naar de Web Server van de slimmemeter ga, zie ik in de debug Log:

    [E][dsmr:137]: !4D13
    Checksum mismatch

    de getallen achter het !teken zijn steeds anders.

    Enig idee wat dit kan betekenen?

  18. Anton Golubchyk

    Thanks, Marcel, got the slimmelezer and did setup as explained.
    It gets the main parameter – consumed energy for peak and off-peak, but there are issues with other parameters.
    – many of them have 0 decimals precision, which results in loss of meaningful info:
    [D][sensor:121]: ‘Power Consumed’: Sending state 0.52000 kW with 0 decimals of accuracy
    [D][sensor:121]: ‘Power Consumed Phase 1’: Sending state 0.21300 kW with 0 decimals of accuracy
    [D][sensor:121]: ‘Power Consumed Phase 2’: Sending state 0.30500 kW with 0 decimals of accuracy
    How can I change that?

    Also, there are checksum errors, which happen almost always at the same place:
    [E][dsmr:138]: !9B50
    Checksum mismatch
    [E][dsmr:138]: !3195
    Checksum mismatch

    Is there any way to fine-tune this?

    1. Marcel

      The only way to fine-tune that, is to install ESPHome within Home Assistant and run your own yaml file within ESPHome.

  19. Peter Bavinck

    I have been using Slimmelezer within Home Assistant for a few weeks without a problem. Yesterday all values are on “Unavailable”. I removed the integration and would like to add the Slimmelezer to HA again. I can’t follow the regular setup as it is not showing it’s own AP. I also noticed that the Slimmelezer does not respond on its IP through a web browser (I used to get a page with info and for flashing).

    Can I hardware reset the Slimmelezer?

    (I upgraded Home Assistant to 2021.10 but timing for things to stop working is off, so don’t think it is related, but who knows?)

  20. Tom

    Vandaag slimme lezer binnen gekregen, alle values staan op [unknown], heeft er vermoedelijk mee te maken dat mijn slimme meter “DSMR 2.2+” op de voorkant heeft staan. Klopt het dat ik daar de aparte download van de productpagina voor nodig heb?

    1. Marcel

      Ja, om twee redenen werkt het niet:
      1) Seriele settings is anders (DSMR 2/3 is 9600 7E1 en DSMR 4/5 is 115200 8N1)
      2) CRC check; Dit zit standaard in de code verwerkt, maar DSMR 2.2 heeft dat niet en die check gooit roet in het eten.

      Heb een paar oplossingen voor je:
      1) Download de DSMR 2.2 versie linkje
      2) Maak je eigen firmware via Michiel Appelman zijn code
      3) Maak gebruik van esp-link

      Mijn voorkeur voor nu gaat uit naar esp-link. Dat maakt een serial2wifi bridge van de SlimmeLezer en dat stuurt alle data door naar waar je het wil hebben (Home Assistant, dsmr-reader, etc)

      1. Tom

        Moet ik nog wat aan de pin configuration aanpassen bij esp-link (preset?)? out-of-the-box krijg ik geen logs in de µC console, en HA zegt `failed to communicate` (port 23, dsmr 2.2)

        1. Marcel

          Als je de esp-link gebruikt van mijn website, staan alle gpio’s goed. Je moet dan alleen de seriële settings goed zetten. Ga via het menu naar “uC Console”. Daar waar 115200 staat, vul je 9600 in en daar waar 8N1 staat, vul je 7E1 in. Dan zou je in de web gui ook data voorbij moeten zien komen.

          1. Tom

            Die instellingen had ik gedaan, er komt geen letter voorbij. Wat kan het dan nog zijn? P1 poort kapot?

      2. Rogier

        ESP link nu in gebruik voor gebruik met HA (vanwege de bug met ESPHome), maar geen gas verbruik in HA te zien. Wel elektriciteit. Enig idee wat dat kan zijn? Gloednieuwe DSRM 5 meter.

  21. Justin

    Vandaag de slimme meter ontvangen.en aangesloten op de meter. Via the browser ook te vinden en de WiFi ingesteld. In HA kwam ook de melding nieuw device and deze werd toegevoegd aan ESPhome. Ik zie dan slimmelezer. Alleen bestaand deze alleen uit 1 device maar geen entities. Heb al wat rondgekeken hier maar nog niet tot een oplossing gekomen. Wat moet ik nog doen?

  22. Matthias Blomme

    Vandaag mijn meter ontvangen en aangesloten, maar er stroomt geen data naar home assistant en ook niets te zien in de webui van de slimme lezer. Enkel uptime en wifi zaken zijn zichtbaar
    De debug log toont 2 type errors

    [E][dsmr:138]: !A3F8
    checsum mismatch

    [E][dsmr:138]: 0-0:96.1.4(50215)
    Invalid string length

      1. Matthias Blomme

        Bij upload van de firmware via de Web interface krijg ik volgende erroe

        Update Failed: ERROR[10]: Magic byte is wrong, not 0xE9

      2. Matthias Blomme

        Hey Marcel

        Ik heb via ESPHome connectie gemaakt en ik krijg deze output, soals je kan zien met de laatste firmware

        [14:13:29][I][app:102]: ESPHome version 2021.9.3 compiled on Oct 15 2021, 14:12:29
        [14:13:29][I][app:104]: Project zuidwijk.slimmelezer version 1.0
        [14:13:29][C][wifi:501]: WiFi:

        [14:13:29][I][app:102]: ESPHome version 2021.9.3 compiled on Oct 15 2021, 14:12:29
        [14:13:29][I][app:104]: Project zuidwijk.slimmelezer version 1.0
        [14:13:29][C][wifi:501]: WiFi:

  23. Justin

    Hi Marcel,

    Great product! Have been looking forward to use the SlimmeMeter. However, the WiFi connects for 10 seconds and then disconnects. Is there a way to fix this? Many thanks in advance!

  24. Peter Bavinck

    After 4 weeks my Slimmelezer stopped working. No data in Home Assistant anymore. No IP on my network. No WiFi Access Point “Slimmelezer”.
    – Is my device already broken?
    – Is there a way to do a factory reset?

  25. Patrick

    Hi Marcel,

    I have re-installed my home assistant on a server and I cannot get the P1 reader ethernet to work. It worked well on my old system, but my home assistant module discovery it, or have it detected by manual added the integration. I can access the P1 reader ethernet through the browser. I have flashed the module, restored factory setting but the home assistant does not detect the P1 reader ethernet. On my old system it worked well.

    Do you have any ideas?

    Best regards,


    1. Marcel

      You did reflash the ethernet module? With what? If you can access the P1 ethernet reader, please put the default template on it. Then in Home Assistant, you need to add it manually,… goto integrations, add integration, dsmr slimme meter. Choose network type, host == ip of ethernet reader and port == 23. Select the right dsmr version and it should work. If you have an older meter with dsmr 2 or 3, check the serial settings.

  26. Patrick Heerschop


    Tijdens de eerste keer kon ik doormiddel van de wifi verbinding de slimme lezer benaderen. Maakte vermoedelijk een typfout in de wifi code van mijn eigen netwerk en nu lijkt de lezer onbenaderbaar. Meermaals van de stroom en uit de P1 poort gehad en opnieuw geprobeerd maar de wifi verbinding tussen de telefoon en de meter blijft telkens kort tot stand en dan vervalt deze.

    Wat te doen, please help

    Groeten Patrick

  27. Lorenzo

    I hooked up my Slimmemeter and configured it. I can see almost all the values in home assistant but I’m missing Voltage Phase 1/2/3, any idea why? The meter is a DSMR v4.2

    Also, what are the electricity Failures and Long Failures? Do I need to be worried for this number?

    Thank you

    1. Bubi

      DSMR is not an exact standard all-across EU. Every provider has it’s own “standards” in terms of which OBIS code contains what, read your meter’s specification on your power provider’s website.
      The “Failures” are simple counters : they contains statistics about power losses from the grid, so there’s no need to worry about the numbers but without power, there’s nothing to measure 🙂

  28. Dave

    Hi Marcel,

    Gisteren je slimme meter ontvangen. Slimme meter aangesloten op USB poort van PC (ook al andere power sources geprobeerd), krijg heel even wireless netwerk slimmelezer te zien. PC krijgt ook ipadres ( Na 10 seconden is het netwerk echter weer weg.

    Binnen die 10 seconden naar connecteren werkt ook niet.

    Nieuwe firmware geflashed maar probleem blijft hetzelfde.

    1. Marcel

      Hey Dave, mail me even door op de order bevestiging te antwoorden. Er kunnen meerdere oorzaken zijn en is lastig om zo op mijn website te behandelen.

  29. sander_lam95

    Hi Marcel,

    I just got my Slimmelezer+, started it with a USB-C charger, setup my wifi-network.

    Now it looks like the P1-port on my Slimme Meter is not powering the Slimmelezer.

    1. With only the P1-cable into the meter and the Slimmelezer, nothing happens
    2. With the Slimmelezer connected to just the USB-C, I only see the Wifi network + uptime in Home Assistant.
    3. With the Slimmelezer connected to the USB-C ánd the P1-cable, I do get the entities filled with data in Home Assistant.

    I have the Iskra AM550 Slimme Meter that should have SMR 5.0.

    So, shouldn’t that mean that the P1 cable alone should give the power to the Slimmelezer? So that option 1 should work?

    Thanks in advance for your answer and thanks for making this product!

    1. Marcel

      Hi Sander, I’m seeing/hearing that a few times more. I haven’t had that on my meter (also AM550). The only reason I can imagine is a mix of the following:
      1) The meter gives a little less juice than the specification states (250mA max)
      2) It’s designed for esp-link, esphome is more cpu consuming and therefore draws a little more power
      3) Where esp-link only sends the telegram, esphome sends/receives more data, and wifi is the biggest power-hungry source.

      1. Bas

        I have the same issue here also with the am550. Can only get it to work powered with the usb cable. Measured the voltage on the outer pins on the p1 and it gives 5v though.
        It is a pitty since my meter is outside of my home about 15m distance and no power outlet there to connect it to. So I have to use a power bank.
        I might be able to pull a rj45 cable to the meter and connect the slimmelezer inside. Are there any restrictions for the length of the cable connected between the p1 and slimmelezer?

        1. Marcel

          Hi Bastiaan, you could use esp-link, that should work without extra powering. It seems that esphome makes the esp8266 use more CPU and WiFi transmissions, what leads to more power consumption. I’ve noticed it on my personal AM550 meter too, where my test meter (TS210-D) doesn’t have that issue. I guess the TS210-D supplies more juice than the AM550. When using esp-link, I dont have that issue.

          Now I’m assuming that you’re talking about the wifi version, which uses a RJ12 cable. The longer the cable the more resistance it creates. I’ve never tested 15 meter (and dont have a large spool to test that). I’d suggest to try esp-link for the fastest/simplest solution.

  30. Rob Aarnts

    Since yesterday morning 02:00 home assistant is no longer registrating energy and gas consumption. The SlimmeLezer is sending the same values for energy and gas consumed. Voltage does change as does power consumed and probably some other sensors to.
    The debug log shows some errors
    Due to the time until when I received proper information in the energy window I have a strong feeling it has to do with daylight saving

    The debug log shows al lot of errors. The have the following format:
    [E][dsmr:138]: !xxxx
    Checksum mismatch

    where xxxx is always a different value

    I have restarted the SlimmeLezer but that didn’t solve the problem

  31. van Aalst Chris

    Hi Marcel,

    I am using the “slimmer lezer’ with the firmware fix for Belgium, was working like a charm; but recently it started giving me ‘Checksum mismatch’-errors in the log. Because of summer-time switch issues in HA, I did a restart of everything, updated HA to latest version (2021.10.7), same for ESPHome (2021.10.3), recompiled my slimmelezer, but still same issues …
    Any idea, what this could be ?



      1. van Aalst Chris


        thanks for help; I turned crc off: error changes, before I had only the WIFI & uptime data and one error (Checksum mismatch) and no data, now I seem to have Wifi & all Power-related data, but there seems to be some kind of mismatch with the OBIS ID field; see my log below.
        (for info: I use the standard firmware with the fix for Belgium; ie
        lib_deps: glmnet/Dsmr@0.5
        lib_ignore: glmnet/Dsmr@0.3

        ===== LOG HERE =====
        [20:44:56][D][sensor:113]: ‘Voltage Phase 3’: Sending state 234.39999 V with 1 decimals of accuracy
        [20:44:56][D][sensor:113]: ‘Current Phase 1’: Sending state 3.53000 A with 1 decimals of accuracy
        [20:44:56][D][sensor:113]: ‘Current Phase 2’: Sending state 11.69000 A with 1 decimals of accuracy
        [20:44:56][D][sensor:113]: ‘Current Phase 3’: Sending state 4.76000 A with 1 decimals of accuracy
        [20:44:56][D][sensor:113]: ‘Power Produced Phase 2’: Sending state 0.00000 kW with 0 decimals of accuracy
        [20:44:56][D][sensor:113]: ‘Power Produced Phase 3’: Sending state 0.00000 kW with 0 decimals of accuracy
        [20:44:56][D][text_sensor:067]: ‘DSMR Identification’: Sending state ‘FLU5\253769484_A’
        [20:44:56][D][text_sensor:067]: ‘DSMR Version Belgium’: Sending state ‘50215’
        [20:44:56][E][dsmr:154]: 0-5204456W)
        Obis ID has number over 255
        [20:44:56][E][dsmr:154]: :41.7.0(02.677*kW)
        OBIS id Empty
        [20:44:57][D][api:098]: Accepted
        [20:44:57][D][api.connection:736]: Home Assistant 2021.10.7 ( Connected successfully
        [20:44:58][E][dsmr:154]: 1-0:2.8.2(000000.150*k
        Invalid unit
        [20:44:58][E][dsmr:154]: 1-0:1.8.1(005071.730*kW:41.7.0(02.657*kW)
        Invalid unit
        [20:44:59][D][sensor:113]: ‘Power Produced’: Sending state 0.00000 kW with 0 decimals of accuracy
        [20:44:59][D][sensor:113]: ‘Voltage Phase 1’: Sending state 233.39999 V with 1 decimals of accuracy
        [20:44:59][D][sensor:113]: ‘Voltage Phase 2’: Sending state 232.70000 V with 1 decimals of accuracy
        [20:44:59][D][sensor:113]: ‘Voltage Phase 3’: Sending state 234.39999 V with 1 decimals of accuracy
        [20:44:59][D][sensor:113]: ‘Current Phase 1’: Sending state 3.51000 A with 1 decimals of accuracy
        [20:44:59][D][sensor:113]: ‘Current Phase 2’: Sending state 11.66000 A with 1 decimals of accuracy
        [20:44:59][D][sensor:113]: ‘Current Phase 3’: Sending state 4.83000 A with 1 decimals of accuracy
        [20:44:59][D][sensor:113]: ‘Power Produced Phase 2’: Sending state 0.00000 kW with 0 decimals of accuracy
        [20:44:59][D][sensor:113]: ‘Power Produced Phase 3’: Sending state 0.00000 kW with 0 decimals of accuracy
        [20:44:59][D][text_sensor:067]: ‘DSMR Identification’: Sending state ‘FLU5\253769484_A’
        [20:44:59][D][text_sensor:067]: ‘DSMR Version Belgium’: Sending state ‘50215’
        [20:45:00][E][dsmr:154]: 1-0:1004191.216*kWh)
        Obis ID has number over 255
        [20:45:01][E][dsmr:154]: 1-0:1.8.1(005071.734*kW*kW)
        Invalid unit
        [20:45:02][E][dsmr:154]: 1-0:1.8.1(005071.735*kW(00.708*kW)
        Invalid unit
        [20:45:03][E][dsmr:154]: 0-0:96.1.130333237343638)
        Obis ID has number over 255
        [20:45:04][D][sensor:113]: ‘Power Consumed’: Sending state 4424.00000 kW with 0 decimals of accuracy
        [20:45:04][D][sensor:113]: ‘Voltage Phase 1’: Sending state 233.10001 V with 1 decimals of accuracy
        [20:45:04][D][sensor:113]: ‘Voltage Phase 2’: Sending state 232.80000 V with 1 decimals of accuracy
        [20:45:04][D][sensor:113]: ‘Voltage Phase 3’: Sending state 234.30000 V with 1 decimals of accuracy
        [20:45:04][D][sensor:113]: ‘Current Phase 1’: Sending state 3.52000 A with 1 decimals of accuracy
        [20:45:04][D][sensor:113]: ‘Current Phase 2’: Sending state 11.21000 A with 1 decimals of accuracy
        [20:45:04][D][sensor:113]: ‘Current Phase 3’: Sending state 4.83000 A with 1 decimals of accuracy
        [20:45:04][D][sensor:113]: ‘Power Produced Phase 2’: Sending state 0.00000 kW with 0 decimals of accuracy
        [20:45:04][D][sensor:113]: ‘Power Produced Phase 3’: Sending state 0.00000 kW with 0 decimals of accuracy

  32. Tompa

    Is there any way to attach a external Wi-Fi antenna? If not, can I extend the cable between the meter and the Slimmelezer to about 5 meter? My meter cabinet reduces the Wi-Fi signal that could be a problem even if it works (-90 dBm), the distance between the access point and meter cabinet is only 5 meters so I don’t think the problem is that.

  33. Tp

    Is there any way to get all the data that the meter sends out? I miss reactive power in Home assistant and my meter sends out the data.

    1. Marcel

      It must have a P1 port to work. All Dutch, Belgium and Luxembourg meters has that for sure. Many other countries within Europe too, yet there are meters with a MBus (RJ45) port only. That is still readable, yet not with my reader. Check the specsheet if it has a P1 port. Dutch providers shows it has a P1, yet can’t tell that for sure for other countries…

      1. Alexey

        I’m in the Netherlands, mine 105A have P1 port. From the document you linked it looks like DSMR is supported, but it is not clear which version, etc.

        1. Marcel

          That should be written on the meter, or shown in the menu… press a few times on the button to “scroll” through the menu. DSMR/ESMR/SMR … all the same. All you need is the number (5, 4, 3, 2).

          1. Alexey

            It turns out mine is DSMR 4.2 (at least, device reports this version). Could you please confirm for this version external power is required? – here I see 4.2 can power device. When I just connect P1 cable – LED on ESP blinks, but then device did not come on WiFi.

            And, BTW, device is quite unstable for me. Sometimes I need to reconnect external power cable many times (5-10) before is boots properly.

            Is it OK to update ESPHome to the latest version? Could you please share a link to the Yaml config?

          2. Marcel

            Yes, unfortunately I can confirm that DSMR 4 requires a power supply. The specifications states that the port is limited to 100mA and I’ve measured 180~220 mA in normal use (DSMR 5 is limited to 250mA). Even the low power esp32 C3 I cant get under the 100mA. A solution could be a big buffer capacitor and limit the wifi transmissions… but then you’re working on the really edge of the limits.

          3. Alexey

            Are ESPHome Version 2021.12.1 compatible?

            Cant make it work with your config:

            [E][dsmr:265]: 0-0:96.7.9(00002JC�1-0:99.97.0(3)(0-0:96.7.19)(191101161137W)(0000000667*s)(181103104116W)(0000004260*s)(000101000001W)(2147483647*s)
            Invalid number
            [E][dsmr:265]: 1-3:0.2.8(���H�0-0:1.0.0(211228190133W)
            Invalid string length
            [D][sensor:113]: ‘SlimmeLezer Wi-Fi Signal’: Sending state -84.00000 dBm with 0 decimals of accuracy
            [E][dsmr:265]: 1-0:22.7.0(00.000*�U�H�!020E
            Last dataline not CRLF terminated
            [E][dsmr:265]: 1-0:21.7.0(00.349*kU�H�1-0:22.7.0(00.000*kW)
            Invalid unit
            [E][dsmr:265]: 1-0:2.8.2(00LL�r�ʺRZ]��
            Invalid number
            [E][dsmr:265]: 1-0:21.7.0(00.360*kU�H�1-0:22.7.0(00.000*kW)
            Invalid unit

          4. Marcel

            I had this because I start using improv, which uses a setting that collides with dsmr 🙁 see here.
            Latest firmware on the productpages solves that. (I removed improv).

  34. Rene

    Hi Marcel,
    Newbie here. I just put myself on the waiting list for the Slimmemeter.
    Currently I have a Toon thermostat which is connected to the P1. I assume I need some form of splitter to be able to connect both Toon and Slimmeter to this port.
    I don’t see this in your shop and I don’t know what to look for. Can you advice me?

  35. Paul

    Hoi Marcel,

    Vandaag de slimmelezer ontvangen. Deze via usb op een usb stekker aangesloten. 1e keer kwam de wifi in beeld op mijn telefoon en de splashscreen kwam in beeld. Thuisnetwerk gekozen en ww ingevuld. Maar ik zie niks op mijn wifi terugkomen via de router. Verbinden met geeft ook geen beeld. Ik krijg op mijn telefoon ook geen wifi meer terug van slimmelezer om bijvoorbeeld opnieuw te verbinden.

    In HA komt ook niks in beeld of kan ik verbinden met de esphome.
    Nog andere opties mogelijk om eventueel opnieuw de wifi op te zetten van de lezer om opnieuw proberen te verbinden?

  36. Mo

    A complete novice here …
    Got the reader today and I hit the P1 port issue with the AM550 (2020 model).

    I flashed the reader with esp-link from the website with v3.2.47. It’s connected to wifi and all, but HA is unable to communicate with it.
    Port 23 is open, but on the esp-link integration I’m getting “Failed to communicate”.

    I only see those logs from the reader debugs
    342807> Accept port 23, conn=0x3fff7d28, pool slot 0
    345784> HTTP GET /log/text: 200, 5ms, h=15328
    348447> HTTP GET /log/text: 200, 6ms, h=15328
    350808> HTTP GET /log/text: 200, 9ms, h=15328
    357872> HTTP GET /log/text: 200, 6ms, h=15328
    361355> HTTP GET /log/text: 200, 6ms, h=15328

    What could be the issue?

    As a side note, the reader is still connected via USB, I want to integrate it first then try to connect it to the P1 port again. I can’t use any power adapter in the meter closet and the meter doesn’t have any USB ports, only the RJ-12 port.


    1. Marcel

      You need to integrate it with esphome and not DSMR Slimme Meter integration. Go to add integration, choose esphome and fill in the name (most likely slimmelezer.local). Chances are high that it is already detected by Home Assistant.

      1. Mo

        Thanks, Marcel. But now I tested connecting it to my meter and even with ESP-Link it didn’t connect to my network, pretty sure the wifi signal is reaching. No possible option to put electricity in my meter closet.
        My meter is ISKRA AM550 (2020) SMR 5.0.
        And I contacted the provider and they said nothing is wrong with the meter and the port should be working.

        Any suggestions? As this doesn’t seem to be working for me. 🙁

        1. Marcel

          Be sure that the 2.4GHz coverage is decent (if you’ve got advanced wifi like I do, you can set the power for each SSID and for 2,4 and 5GHz separate). It’s using 2,4GHz only. And make sure channels are set fixed.

  37. Jeffery Bray

    Hi Marcel.
    I received 2 of your slimmemeter+ and they are great. My problem at the moment is that I have two of them on the same home-assistant instance. I have two devices in the slimmelezer integration, however most of the entity names clash, so the readings for the two separate devices are being written into the same entities. Is there a way that I can specify the device name in the entity so that I can separate the readings from each device?

    1. Marcel

      I advice you to use your own code. Then you can give them names the way you want, or use “name_add_mac_suffix: true”. Than the name will be slimmelezer-xxxxxx (where xxxxxx is the last 6 characters of the MAC address)

      1. Jeffery Bray

        Thanks Marcel.

        I wrote my own code. I named them slimmelezer-1 and slimmelezer-2. I renamed all the sensors with a ‘1’ and ‘2’ identifier. This is working well.
        However one of the sensors has a poor wifi signal and sometimes it drops out. Then it does not reconnect. Do you have any suggestions to help it reconnect?

  38. René Kok

    Hi Marcel,
    Zojuist de SlimmeMeter ontvangen en aangesloten. Het slimmelezer netwerk verscheen, netjes aangemeld op mijn lokale wifi netwerk.

    HA herkent niets automatisch. Dus ik heb via integrations -> ESPHome geselecteerd.
    Echter, de SlimmeLezer is bereikbaar op (fixed IP address nu) en niet via slimmelezer.local. Via het ip adres krijg ik netjes de content te zien. Maar niet via port 6053.
    Ik gebruik / letsencrypt en mogelijk heeft het daar mee te maken?
    Wat ik ook probeer in het ESPHome connection settings scherm, het werkt niet. Ik krijg structureel de melding “Can’t connect to ESP. Please make sure your YAML file contains an ‘api:’ line.”

    Enig idee wat te doen? Suggesties waar te zoeken?

    1. René Kok

      Okay, never mind. Ik was blijkbaar niet geduldig genoeg.
      Opeens herkende HA hem wel en de configuratie is automatisch gelukt. Negeer mijn bericht ajb!

  39. Michael De Neve

    Beste Marcel,
    Slimme Lezer + goed ontvangen waarvoor dank!
    Ik draai Home Assistant en de slimme meter werd onmiddellijk herkend. 1 apparaat en 33 entiteiten.
    Echter krijg ik niets van data te zien. Ik heb een Belgische meter die onlangs is geïnstalleerd, de nieuwe digitale meter dus. (5B)
    De slimme lezer hangt nu al een dag en een nacht aan, maar geen enkele data te zien.
    Mocht je meer info willen, dan hoor ik het graag.
    Prettig eindejaar alvast.

      1. Michael De Neve

        Bij deze bevestigd, het werkt!

        – account aanmaken bij Fluvius indien dit nog niet is gebeurt
        – ean code electriciteit ingeven
        – aanvraag tot poort te openen onder poortbeheer

        Prettig eindejaar aan iedereen.

  40. Sebastiaan

    I’ve seen it mentioned before, but for the record:
    I also have a AM550 and slimmelezer needs an external USB powersupply for it to work.

    @Marcel thanks for your hard work and quick shipment!

    1. Marcel

      Most likely the ESP12F has too much CPU load and too much WiFi data transmissions, which causes to draw too much power. Either use your own yaml file and strip it to the bear minimum, or use esp-link.

  41. Danny van Oijen

    Zou deze aan te sluiten zijn middels een micro usb kabel met open eind op een beltrafo?
    Het gaat zich om een hager beltrafo ST303N?

    1. Marcel

      Nee, dat gaat niet werken. Die travo is sowieso AC en er moet DC in. Daarnaast is de trafo 8v en de power regulator kan max 6v in aan (is ontworpen op USB 5 volt)

  42. Ivan Laktašić

    Hi I got my slimmelezer yesterday and I connected it to wifi successfully. But when I connect it to my p1 port on am550 Iskra meter it doesn’t respond, seems it has no power. When I connect it to usb and p1 simultaneously I can see it in homeassistant but there is no data from meter only network info.

  43. Pieter

    Hi, ook een n00b hier. Ik heb de SlimmeLezer+ aan m’n wifi gekoppeld, en ik zie hem in HomeAssistant als device met 33 entiteiten. Echter in ESPHome binnen HA zie ik hem niet, daar zie ik “it looks like you don’t have any devices” en kan er eentje toevoegen. Dat kan ik doen, maar ik weet niet welk type board ik moet opgeven: op de SlimmeLezer+ zit een ESP-12F, maar deze staat niet in de lijst (wel ESP-12E).

    Vraag: moet ik de SlimmeLezer in ESPHome opvoeren als ik de configuratie wil bewerken? Ik wil mijn SSID graag hidden houden, hiervoor is volgens jouw doc een extra parameter “fast_connect” nodig, maar volgens mij heb ik op dit moment geen mogelijkheid om dit erin te krijgen. Of mis ik iets?

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