Is 5V Active-Low Relay Module 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
Single-channel 10A relay controller for automating appliance power garage door openers or low-voltage solenoid valves.
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 | GPIO Digital / 3.3V Transistor |
| Bridge Required | NO |
| Border Router Needed | None |
| Hardware Capabilities & Peripherals | Relay Switch State Power Restore State Note: these entities come from the ESPHome configuration you flash — each one needs its matching component in that YAML before it appears. |
| Pairing Complexity | Plug-and-Play |
| Factory Reset Instruction | Hold D3/FLASH to GND while plugging in USB power. |
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_esp8266_relay_esphome.yaml and run esphome run emb_esp8266_relay_esphome.yaml. The first flash goes over USB. If it is not detected, hold D3/FLASH to GND while plugging in USB power 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 5V Active-Low Relay Module on ESP8266. Untested on hardware — verify wiring and pins against your own board.
# ESPHome configuration for 5V Active-Low Relay Module
# Host: ESP8266. 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_esp8266_relay_esphome
friendly_name: "5V Active-Low Relay Module"
esp8266:
board: nodemcuv2
logger:
api:
encryption:
key: !secret api_encryption_key
ota:
- platform: esphome
password: !secret ota_password
wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
# Active-low: the relay closes when the input is pulled to ground, so the
# switch is inverted and starts off. GPIO5 (D1) is safe at boot; GPIO0, 2
# and 15 are strapping pins and would click the relay during reset.
switch:
- platform: gpio
name: "Relay"
pin:
number: GPIO5
inverted: true
restore_mode: ALWAYS_OFF
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 5V Active-Low Relay Module? Submit a pull request or report corrections to our index.