Is CSE7766 UART Energy Monitor Compatible with Home Assistant (ESPHome)?
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.
Compatibility Overview
The metering chip from the Sonoff POW R2 as a bare module: streams voltage current and power over a one-way 4800-baud UART while sitting directly on the measured line.
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 | Power (W) Current (A) Voltage (V) Energy (kWh) Apparent Power (VA) 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 | Advanced |
| Factory Reset Instruction | Hold BOOT button for 3s. |
Wire, Flash, Adopt, Check
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.
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_cse7766_esphome.yaml and run esphome run emb_esp32_cse7766_esphome.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.
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.
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 CSE7766 UART Energy Monitor on ESP32. Untested on hardware — verify wiring and pins against your own board.
# ESPHome configuration for CSE7766 UART 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_cse7766_esphome
friendly_name: "CSE7766 UART 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: 4800
parity: EVEN
# One-way stream: only RX is used. The chip sends several updates a
# second, hence the throttle filters.
sensor:
- platform: cse7766
voltage:
name: "Voltage"
filters:
- throttle_average: 10s
current:
name: "Current"
filters:
- throttle_average: 10s
power:
name: "Power"
filters:
- throttle_average: 10s
energy:
name: "Energy"
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.
Report a Pinout Error or Submit Tested Code Snippets
Found a pin mapping quirk or built a custom ESPHome YAML driver for CSE7766 UART Energy Monitor? Submit a pull request or report corrections to our index.