Powermeter to MQTT & Webserver via Modbus using Ethernet or WiFi with OTA

A Firmware-Project for Espressif microcontrollers (such as ESP32, ESP32S3, ESP32H2 ...) that reads Powermeter registers and publishes the data to MQTT, while also providing a Webserver interface for real-time-monitoring and logging.

It works with almost all Eastron SDM-Powermeter-Device (integrated) and it is configured for the Eastron SDM630. Only small adjustments needed, to work with a different type, or Modbus-Powermeters from other vendors.

This is purely based on ESP-IDF (Espressif IoT Development Framework), it is NOT an Arduino-Project.

✅ Features

• Continuously reads Powermeter's values via Modbus RTU.
• Distinguish between priority and normal values. Priority-values are read more often.
• Publishes read values to an MQTT broker for integration with IoT platforms.
• Only publishes values to MQTT if they have changed significantly (per-register threshold configurable).
• Embedded async Webserver (on ESP) for real-time monitoring.
• WebSerial interface to view live logs in the browser.
• LAN connection via either with Ethernet or WiFi.
• Synchronize local time using an NTP Server, allowing data to be timestamped.
• Supports Over-The-Air (OTA) updates, eliminating the need for USB access.
• Devices can be reached by Hostname or IP (can be fixed IP).
• HTML-Pages are stored in LittleFS (File-System) for easy updates and editing.
• Consists of 7 reusable components plus a main application.
• Almost all components include menuconfig configuration options and are designed for reused in other projects.

🧰 Hardware Requirements

• Microcontroller Board with any chip of the ESP32-Family.

  • Recommended:
    Chips with JTAG integrated like ESP32S2, ESP32S3 or ESP32H2 for easy debugging via USB.
    Search for 'JTAG' in technical datasheet of the chip, ESP32S3-Datasheet-Example.

• Powermeter with a Modbus-Interface.

• UART(Serial)-to-MOBUS(RS485)-Adapter.

  • Recommended:
    With galvanic isolation of MCU from MODBUS.

• Optional: Ethernet-Shield (e.g. with W5500-Chip), for to LAN connection via Ethernet.

💻 Software Requirements

• For compile and flashing: ESP-IDF-Tools.

Recommended:

• ESP-IDF-Extension in Visual Studio Code as IDE, which includes all required tools and project configuration UI.

🚀 Getting Started

Setup

1. Clone this repository:

   git clone https://github.com/twischi/Powermeter-values-to-MQTT-and-Websever.git
   cd Powermeter-values-to-MQTT-and-Websever

2. Configure the project:

   idf.py menuconfig

   • Set Wi-Fi credentials, MQTT broker address, and power meter parameters.

3. Build and flash:

   idf.py build
   idf.py -p <PORT> flash

4. Monitor output:

   idf.py monitor

🧱 Project Components

Located in the 'components/'directory and used by the main application:

See the list of components:   COMPONENTS.md

🛠️ Scripts in Project-Folder

Script-Name	Script-Type	Purpose
ota_update/install_py_requirements.sh	Shell	Installs Python modules needed for ota_server-one-shot.py
ota_server-one-shot.py	Python	Serves the OTA file over local network using Zeroconf; shuts down after delivery.
provide_ota_update.sh	Shell	Just for convenience, to start ota_server-one-shot.py
toggle_project_config.sh	Shell	Enables/disables the Project Configuration Editor in VSCode ESP-IDF extension.
clean_all.sh	Shell	Cleans everything related with 'build' including skdconfig and depencency.lock leads to a 'virgin'-state.

📄 Other Files in Project-Folder

File	Content
version.txt	Holds the firmware version, written to None-Volatile-Storage(NVS) during build.
storage_at_runtime/prm_webserver.html	Webpage to monitoring the Powermeter register-values. Updated at runtime after each read-cycle.
storage_at_runtime/webserial.html	Webpage to show log-messages during runtime (WebSerial)
partitions.csv	Partition layout definition needed for OTA and LittleFS.

📜 License

This project is licensed under the MIT License.

🙌 Acknowledgements

• ESP-IDF

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