标签：#esphome

ESP32 Energy Metering with HLW8032, BL0942, and ESPHome ESP32 energy metering with HLW8032, BL0942, and ESPHome is not just about reading voltage, current, power, and energy. This article explains how to design the UART boundary, reporting cadence, calibration, entity model, and diagnostics as one stable data path. Many ESP32 energy metering projects start well. You connect an HLW8032 or BL0942 module, enable the matching ESPHome component, and Home Assistant quickly shows voltage, current, power, and energy. But reading values is not the same as building an energy metering node that can run reliably over time. The core conclusion is this: the hard part of ESP32 energy metering is not whether HLW8032 or BL0942 can be read. The hard part is designing the metering chip, UART, Wi-Fi behavior, ESPHome entities, calibration, and diagnostics as one stable data path. If the project focuses only on sensor YAML, it can later fail on transient loads, serial conflicts, unstable sampling, Wi-Fi reconnects, Home Assistant database growth, and calibration drift. In this article, an ESP32 energy metering node means an edge device where ESP32 reads voltage, current, power, and energy from a metering chip such as HLW8032 or BL0942, then exposes those values through ESPHome to Home Assistant or another upper-layer platform. It is suitable for device energy monitoring, trend observation, and low-risk operational diagnostics. It should not be treated as a billing-grade meter or an electrical protection device. If the goal is to monitor the energy behavior of one appliance, one small circuit, or one commercial device inside Home Assistant, ESP32 + ESPHome + HLW8032/BL0942 is a fast and low-cost path. If the goal is billing, electrical protection, high-accuracy compliance measurement, or safety interlocking, use certified meters, protection devices, or industrial acquisition hardware instead of stretching an ESPHome node beyond its boundary. 1. Why energy metering is more fragile than or