Smart Analog Intercom Doorbell for Keyless Entry

Requirements:

• BareSIP configured for Phone Call (optional)
  • create /usr/share/baresip/unlockdoor.wav for sound played when unlocked
• MQTT Broker to unlock door (optional)
• 12V analog intercom, tested on Aiphone VC-K
• Raspberry Pi GPIO compatible (e.g. Raspberry Pi Zero 2 W)
• Sound Card with Aux In and Aux Out (e.g. IQaudio Codec Zero)

Features:

• Phone call with button 5 pressed to unlock
• MQTT integration for Home Assistant
• Web access
• Secure Link to open the door

Config:

Exemple intercom.yaml

HTTP_PORT: 8080
BARESIP_ENABLED: true
BARESIP_HOST: "localhost"
PHONE_NUMBER: "0019998881234"  # require if BARESIP_ENABLED
MQTT_ENABLED: true
MQTT_BROKER_HOST: "192.168.1.245" # require if MQTT_ENABLED
MQTT_BROKER_PORT: 1883
MQTT_CLIENT_ID: "intercom"
MQTT_BASE_TOPIC: "intercom/frontdoor"
MQTT_USERNAME: "intercom"
MQTT_PASSWORD: "CHANGEME"

Aiphone VC-K

1. Home to Entrance, line level (1Vpp after high-pass filter)
2. Entrance to Home, line level (1Vpp after high-pass filter)
3. GND, 0V
4. Button for door release (Default: High, press: Low)
5. Call signal (Default: Low, call: High)

High ~12V
Low ~0V

To enable entrance mic, connect pin3(GND) with a resistor(330 ohm) to pin2(Entrance to Home)

Schematic

smart-intercom.kicad_sch