This project lets you remotely unlock your outdoor gate using ESPHome and Home Assistant.
It also allows you to trigger actions (like turning on lights) when the door is opened.

• Check your lock type first

  • This guide is for 12V AC locks
  • If your lock is 12V DC, wiring is different

• Do NOT power the lock for more than ~2 seconds

  • Continuous power will damage the lock

• Fail-safe behavior

  • Make sure your relay is configured to stay OFF on boot
  • Otherwise the lock may stay powered and burn

• ESP8266 (ESP-01 or similar)
• 1-channel relay module (5V, supports external trigger)
• 220V AC → 12V AC transformer (for lock)
• 5V power supply (for ESP + relay)
• Electric door lock (12V AC)
• Wires

I used this ESP board with built in relay module

You will use two separate power sources:

1. 12V AC → for the lock
2. 5V DC → for ESP + relay module

⚠️ Do NOT mix them

The relay works like a switch to allow current to flow to the lock.

• One wire from transformer goes directly to lock
• The other wire goes through the relay (COM → NO)

    220V AC
       │
┌───────────────┐
│  Transformer  │  (220V → 12V AC)
└───────────────┘
│       │
│       │
│       └───────────────┐
│                       │
│                    [ LOCK ]
│                       │
│                       │
│               ┌───────────┐
└──────────────▶│   COM     │
│   RELAY   │
│   NO      │◀─────── back to transformer
└───────────┘

            220V AC
               │
               │
       ┌────────────────┐
       │  Transformer   │
       │  220V → 12V AC │
       └────────────────┘
            │      │
            │      │
            │      │
            │      └───────────────┐
            │                      │
            │                  ┌─────────┐
            │                  │  LOCK   │
            │                  │ (12V AC)│
            │                  └─────────┘
            │                      │
            │                      │
            │               ┌───────────┐
            └──────────────▶│   COM     │
                            │   RELAY   │
                            │           │
            ┌──────────────▶│   NO      │
            │               └───────────┘
            │
            └───────────────────────────── back to transformer


    ESP8266                Relay Module
  ┌──────────┐          ┌─────────────┐
  │          │          │             │
  │  GPIO0 ───────────▶│ IN          │
  │          │          │             │
  │  VCC  ───────────▶ │ VCC (5V)    │
  │          │          │             │
  │  GND  ───────────▶ │ GND         │
  │          │          │             │
  └──────────┘          └─────────────┘

1. ESP sends signal → relay turns ON
2. Relay closes circuit → 12V AC reaches lock
3. Lock opens
4. After ~200ms → relay turns OFF
5. Lock stops receiving power

• Lock is only triggered briefly (~200ms)
• Cooldown prevents repeated triggers
• Relay is always OFF on boot

• You get a button: "Unlock Door"
• Can be used in:
  • automations
  • mobile app
  • dashboards

Example use:

• Unlock door
• Turn on front light
• Send notification

• Use good quality relay (cheap ones may fail)
• Keep wiring clean and insulated
• Test with short pulses first
• If lock behaves weird → check AC vs DC

• Add door sensor (open/closed)
• Auto light on open
• Camera snapshot on unlock
• Add keypad or RFID

• ESPHome YAML is provided separately in this repo
• Adjust GPIO pin if needed
• ESP-01 may require proper flashing setup

Free to use and modify