Hardware Matrix

Is PZEM-004T V3 AC Energy Monitor Compatible with Home Assistant (ESPHome)?

Verdict Badge
VERDICT: [ COMPATIBLE (MANUAL CONFIG REQUIRED) ]
Protocol: UART Serial / 3.3V
Bridge Needed: NO
⚡ DANGER: MAINS VOLTAGE PRESENT

This installation carries line voltage capable of causing severe electric shock, injury, or fire. Disconnect power at the breaker before wiring, verify with a non-contact voltage tester, and consult a qualified electrician if you are not confident working with mains circuits. Do not rely on this page as your only reference — confirm terminal assignments against the manufacturer's own documentation.

Electrical Specifications

Always confirm pin assignments against the manufacturer datasheet before wiring.

📖 Source: Peacefair PZEM-004T V3.0 user manual
Power InputMeasurement side fed from the 80–260V AC line; TTL side is passive and needs external 5V
GPIO Logic Voltage5V TTL UART (9600 8N1), optocoupler-isolated — all four pins (5V, RX, TX, GND) must be connected
Current Profile0–100A via external CT (PZEM-004T-100A); 0–23kW active power
Ingress ProtectionNone — exposed board, enclosure required; −20°C to +60°C working range

Compatibility Overview

Single-phase AC energy meter measuring an 80-260V mains circuit through an isolating current transformer; the measurement side connects directly to line voltage and must be enclosed before energisation.

Wiring

Terminal assignments for this device

Terminal diagram not shown.

This device carries mains voltage, and its terminal markings vary by model and revision. Publishing a generic AC terminal diagram here would risk you wiring live conductors from a drawing that does not match the part in your hand — so we do not print one. Use the manufacturer's own installation sheet for terminal identification.

Technical Specification Matrix

Feature / Attribute Specification / Status
Hardware Protocol UART Serial / 3.3V
Bridge Required NO
Border Router Needed None
Hardware Capabilities & Peripherals
Voltage (V) Current (A) Power (W) Energy (kWh) Frequency (Hz) Power Factor

Note: these entities come from the ESPHome configuration you flash — each one needs its matching component in that YAML before it appears.

Pairing Complexity Intermediate
Factory Reset Instruction Hold BOOT button for 3s.

Wire, Flash, Adopt, Check

1

Wire it up

Follow the bus reference above. The host pins in the configuration are defaults — any free GPIO of the right kind will do, as long as the YAML names the pin you actually used.

2

Flash the configuration

Create a new device in the ESPHome dashboard (the Home Assistant add-on) and paste the configuration below into it, or save it as emb_esp32_pzem004t_ha.yaml and run esphome run emb_esp32_pzem004t_ha.yaml. The first flash goes over USB. If it is not detected, hold BOOT button for 3s to put it in download mode. Every update after that is over the air.

3

Adopt it in Home Assistant

Settings → Devices & Services. A node on the same network shows up as a discovered ESPHome device within a minute of joining Wi-Fi; choose Configure and enter the API encryption key from your secrets.yaml. If discovery does not find it, add the ESPHome integration by hand with the node's IP address.

4

Check it works

The entities on this page appear under the device in Home Assistant and update at the configured interval. The ESPHome log (Logs in the dashboard, or esphome logs) reports the setup of each component and any bus scan results at boot.

ESPHome Configuration

Starting configuration for PZEM-004T V3 AC Energy Monitor on ESP32. Untested on hardware — verify wiring and pins against your own board.

# ESPHome configuration for PZEM-004T V3 AC Energy Monitor
# Host: ESP32. Pin numbers below are host-side defaults — any free
# GPIO will do, and you should change them to match your own wiring.

esphome:
  name: emb_esp32_pzem004t_ha
  friendly_name: "PZEM-004T V3 AC Energy Monitor"

esp32:
  board: esp32dev
  framework:
    type: esp-idf

logger:

api:
  encryption:
    key: !secret api_encryption_key

ota:
  - platform: esphome
    password: !secret ota_password

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

uart:
  rx_pin: GPIO16
  tx_pin: GPIO17
  baud_rate: 9600

modbus:

sensor:
  - platform: pzemac
    voltage:
      name: "Voltage"
    current:
      name: "Current"
    power:
      name: "Power"
    energy:
      name: "Energy"
    frequency:
      name: "Frequency"
    power_factor:
      name: "Power Factor"
    update_interval: 10s

Before you flash: the !secret values come from your secrets.yaml, and the GPIO numbers are host-side defaults rather than properties of this part — change them to match how you actually wired it.

🛠️ Hardware Correction & Field Contributions

Report a Pinout Error or Submit Tested Code Snippets

Found a pin mapping quirk or built a custom ESPHome YAML driver for PZEM-004T V3 AC Energy Monitor? Submit a pull request or report corrections to our index.

Frequently Asked Questions

Does PZEM-004T V3 AC Energy Monitor work without an internet connection?
100% local UART Modbus readout.
How is PZEM-004T V3 AC Energy Monitor powered and wired to the host board?
5V VCC UART TX=GPIO16 RX=GPIO17; AC terminals connect to 80-260V mains via the supplied CT — isolate supply before wiring.
How does the host board reach Home Assistant (ESPHome)?
Wi-Fi 2.4GHz.

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