Energy Meters (Industrial & Building Automation): open-source projects that exist because someone reverse engineered a closed product, sorted by GitHub stars.
ESP firmware reading HAN port data from smart electricity meters to MQTT
Home Assistant sensor for Tauron eLicznik energy data via unofficial API
Reverse engineered schematics and interface software for the PZEM-004T power meter
ESPHome components including iNode BLE energy meter support
Home Assistant integration for Kamstrup 403 heat meters via the optical KMP protocol
Python library for the Wiener Netze smart meter private API
Retrieves energy data from a Powerpal meter reader over its reverse-engineered BLE protocol
Reverse engineered tools and docs for the Emerald Electricity Advisor
Implementation of the Kamstrup Meter Protocol (KMP)
Python library reading Kamstrup Multical 402 heat meters over the optical eye
ESPHome component for Kamstrup Multical 402 heat meters
ESP8266 interface for encrypted Kamstrup Omnipower meters (Radius) HAN port
ESP Modbus-to-Wi-Fi reader for Portuguese EDP smart meters (HAN port)
ESPHome component reading Axioma Qalcosonic W1 water meters via NFC
Wireless MeterLogger for Kamstrup heat energy meters
Kamstrup IR optical eye reader
ESPHome component for Nartis I100/I300 electricity meters over RF433
Home Assistant integration for Kamstrup Multical 66C heat meters
Driver for the Kamstrup 685-382 electricity meter over the KMP serial protocol
Emulates the Modbus registers of an Eastron SDM630 power meter
Go client for Kamstrup and other power meters