Open your garage door from your phone with ESP32, ESPHome and Home Assistant

Also available in French.

Control the garage from your phone and know if it stayed open: a relay in parallel with the wall button sends the same short pulse as a physical press; a reed switch reports closed when the door is down. Home Assistant shows a garage cover in the mobile app.

Safety — read first

Confirm in the opener manual a dry-contact / momentary push-button input (low voltage). If the manual does not describe it, stop.
Never work on mains inside the opener unless you are qualified—power off before opening the housing; wire only the low-voltage button terminals.
Keep photo eyes, force limits and obstacle detection—never bypass them.
Remote access: use Home Assistant Cloud, Tailscale or VPN—not a naked port forward. Enable 2FA on accounts.
Add confirmation in the dashboard before toggling—pocket taps are real.
Only operate remotely when you are sure no one is under the door.

Goal

Toggle from Home Assistant with confirmation.
True open/closed state from reed.
Alert if open too long.

Time, level, parts

Time	Level	Parts
2–3 h	Intermediate	ESP32, 3.3 V-compatible relay module, wired reed, USB 5 V supply

ESP32 DevKit — UK · US
1-channel relay that triggers on 3.3 V logic (many “5 V” boards fail on ESP32 GPIO)—UK search · US
Wired door reed — UK · US

A Shelly in dry-contact mode can substitute for the relay if you follow that device’s manual the same way.

Wiring

Part	Pin	To
Relay VCC		ESP32 3V3 (or 5 V per module spec)
Relay GND		GND
Relay IN		GPIO26
Relay COM / NO	dry contact	Opener button terminals (parallel with wall button)
Reed		GPIO27 + GND (internal pull-up)

Reed closed when door fully down (magnet aligned).

ESPHome

Install ESPHome add-on. Use secrets for Wi-Fi and API keys. Download the full example: /code/esphome/porte-garage.yaml.

Core behaviour:

Pulse relay ~700 ms (adjust 0.5–1 s per opener manual)—never latched (restore_mode: ALWAYS_OFF).
Template cover: open_action only if reed says closed; close_action only if open—so “open” on an open door does not start closing by mistake.
Script mode: single debounces double taps.

Flash USB first: esphome run porte-garage.yaml; then OTA.

Home Assistant UI

Dashboard button with confirmation:

type: button
entity: cover.garage_door
name: Garage door
show_state: true
tap_action:
  action: toggle
  confirmation:
    text: "Operate the garage door?"

Alert if open 15 minutes—adapt entity ids to yours.

After power loss

Firmware runs on the ESP32; relay defaults off at boot—power glitch should not pulse the door.

Common mistakes

Relay on power terminals instead of button input.
Relay that needs 5 V on IN while ESP32 outputs 3.3 V.
Pulse too long.
Exposed HA on the internet without VPN/TLS.

Verification note

YAML was validated with esphome config / compile (ESPHome 2026.9); we did not install on a live door—your opener manual is authoritative.

Docs: ESPHome template cover · HA remote access.

Also: ESPHome temperature · door reed on Pi · ESP32 projects.

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