A demo ESP32 home energy monitor display that reads two solar inverters, the grid meter and the house battery — from their own ports on the LAN, not the cloud 

The data was already in the house. Two Steca inverters, a HomeWizard P1 on the meter, an AEG battery — each with its own app, each reporting to its own vendor cloud, none of them talking to each other. I wanted one piece of glass that showed all of it at a glance and read the boxes directly, on my own network.

 

Figure 1. Overview screen — data and time on top, along with the actual Wifi signal quality. Tap here (on top) and the menu opens. Solar panels shows current Watts from the panels on the left.

This is a demonstration build, not a product. It runs on the same board as my weather clock. Different hardware would need different reader code — but the approach holds for any inverter, meter or battery that exposes an open interface on your LAN, and the recurring lesson was that the number I actually wanted was usually the one the vendor’s own app does not show you.

    The same P1 meter an/or AEG battery should work right away. Separate parts in the overview display can be enabled/disabled from view.

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See the download section for the full documented article: 704 - Energy_Monitor_Article_rev03.pdf

Flash the ESP32 DevKit V1: unpack the zip and flash the compiled binary "704_v44.ino.merged.bin" with esptool v4, or with this command: "esptool --chip esp32 --baud 921600 write-flash 0x0 704_v04.ino.merged.bin"


Note 1: (9 Sep. 2026): KiCad schematics pdf: just added.



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