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Will there be an update of Pow-U with ESP32?


During the design of Pow-U, one of the major challenges was to power it from the M-bus line on the HAN-port. In this way, Pow-U does not need a separate power supply.

We would love to use ESP32 also on Pow-U, but for the time being all versions of ESP32 consume too much power to make this possible. During S1/2022 we upgraded the Pow-K to use and ESP32-S2 module. However, also the S2 consumes too much power to be used on Pow-U.

We'll keep an eye on new products from Espressif, and as soon as a suitable and compatible module hits the market we'll start working on it!

But for the time being, the answer is sadly: No.

Update 5th September 2022

We have great news!

We finally found the solution, and have now redesigned the Pow-U around an ESP32-S2-MINI module. We have ordered a first production batch, and we expect to start shipping the new Pow-U around 1st October -22.

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  • Wifi performance
    By: Jørgen Bøhm On 19-Dec-2022

    I have a pow-u with ESP8266 and are very happy with it. I had to use an wifi ekstender , is there any change in wifi performance with the ESP32 pow-u ?

    Replied by: Egil Opsahl On 20-Dec-2022 Good to hear you are happy with the ESP8266!
    The ESP32 is more immune to Broadcast and Multicast messages (typically from Apple-TV, Chromecast devices etc) on the wifi network - which in some environments prevent the ESP8266 from going to auto modem sleep, causing it to lose voltage and finally reboot.
    The ESP32 also reacts to a "new" command (introduced in the Ardunio framework early 2022). It enables setting the Wifi modem in two power saving states: "Minimum" and "Maximum". Exploiting these setting made it possible to use ESP32-S2 in this application, even though it consumes more power than ESP8266.

    Pow-U is shipped with the setting at "Maximum", which might in some cases make the GUI seem a bit less responsive. If this is problematic, try changing it to "Minimum" (Config->Wifi menu). If voltage is stable - fine, stay like that!

    Replied by: Egil Opsahl On 20-Dec-2022 Pow-U can only be used on a Kamstrup meter if it is powered through the USB socket.

  • Use Pow-U for Kamstrup
    By: Stian On 10-Oct-2022

    With the new ESP-32-S2-Mini, will Pow-U also be possible to use with Kamstrup? Currently only Pow-K module is said to work with Kamstrup HAN-NVE modules (

    Replied by: Egil Opsahl On 14-Oct-2022 No, the Kamstrup HAN-NVE module that provides M-bus has very limited current supply capability. You should use Pow-K on the Kamstrup meter.