Hacking my door phone

• Overview
• Siedle HTS-711
  • Manuals for other similiar Siedle 1+n systems
  • Terminals
• Triggering the buzzer
  • Home Assistant templating
• Detecting doorbell
  • ESPHome config
• CHANGELOG
• References

Overview

The goal of this project is to:

1. Detect when someone rings my doorbell.
2. Trigger the buzzer for the door to the staircase.

The ringer on my doorbell makes a deeply horrible sound. It would be much better to be able to detect a ring and based on the state of my home, use some combination of:

• Playing a pleasant chime through the speakers.
• Using light signals, for example softly pulsing some LEDs.
• Sending a push notification while away.
• Just doing nothing and ignoring the whole busines.

In the current state of the project, I'm about to control the buzzer and detct when the doorbell outside the door to my flat is pressed. The remaining part is detecting when the doorbell on the street is pressed. The project started by using a Z-Wave relay to detect the buzzer and then used ESPHome for the ring detection, but will move to ESPHome to keep everything in one single unit.

A very useful and interesting project is ESPBell-LITE.

I replied to a /r/homeautomation thread on Reddit where someone else was working on a similar project.

Siedle HTS-711

The intercom/buzzer/door-phone in my flat is a Siedle HTS 711-01¹.

Manuals for other similiar Siedle 1+n systems

Terminals

As per the datasheet and wiring digarams from Siedle² (on pages 3-6), the pinout is:

In den Plänen liegt die gemeinsame Ader an Klemme 1 und die Rufader "n" an Klemme 7. Beide Adern müssen im gleichen Kabel geführt werden. Klemme 7 wird im Ruhezustand über das Tasten-Modul mit Gleichspannung versorgt. Solange die Klingeltaste gedrückt wird, steigt die Spannung auf den vollen Wert an.

In the plans, the common wire is connected to terminal 1 and the call wire "n" to terminal 7. Both wires must be routed to the same cable. In the idle state, terminal 7 is supplied with DC voltage via the button module. As long as the button is pressed, the voltage increases to full potential.

Triggering the buzzer

Started on the easy part first, triggering the buzzer for the staircase door. Since the buzzer for the house door is triggered by a simple switch, all we need is a relay that we can control remotely.

Used a Fibaro FGBS-222 implant that I had on hand, which is (among other things) a relay (connected to Z-Wave JS, controlled with Home Assistant).

This is a really simple switch, it just closes a circuit which triggers the buzzer. I soldered wires to each end of the open side of the circuit that the button closes, and use one of the relay contacts on the FGBS-222 to close it.

Instead of using Z-Wave for this part, the FGB-222 will be replaced with a relay connected to an ESP32 with ESPHome that would both detect the doorbell signal and trigger the buzzer.

Home Assistant templating

Configuration for Home Assistant can be found at infra:roles/hass-core/files/packages/doorbell.yaml:

---

script:
  momentary_switch:
    icon: mdi:button-pointer
    mode: parallel
    sequence:
      - service: switch.toggle
        target:
          entity_id: |
            {{ target_switch }}
      - delay:
          milliseconds: |
            {{ press_for_ms | int }}
      - service: switch.toggle
        target:
          entity_id: |
           {{ target_switch }}
    fields:
      target_switch:
        description: |
          entity_id of the switch to toggle like
          a button (a list of entity_id's also works)
        example: switch.smart_implant_out1
      press_for_ms:
        description: |
          how long to press the button, in
          milliseconds
        default: 200

template:
  - binary_sensor:
      - name: doorbell_buzzer
        state: |
          {{ is_state("switch.doorbell_buzzer", "on") }}
        icon: |
          {% if is_state("switch.doorbell_buzzer", "on") %}
          mdi:electric-switch-closed
          {% else %}
          mdi:electric-switch
          {% endif %}

  - button:
      name: doorbell_buzzer
      icon: |
        {% if is_state("switch.doorbell_buzzer", "on") %}
        mdi:electric-switch-closed
        {% else %}
        mdi:electric-switch
        {% endif %}
      press:
        - service: script.momentary_switch
          data:
            target_switch: switch.doorbell_buzzer
            press_for_ms: 200

This assumes that the switch entity on the FGBS-222 module is named switch.doorbell_buzzer, and creates a button.doorbell_buzzer entity that triggers the relay.

Detecting doorbell

The ERT header on the Siedle HTS-711 circuit board is $0VDC$ to the header 1 while idle and gets pulled up to around $14VDC$ when the doorbell for the flat door is pressed (and approx $0VDC$ to the header 7).

Using a SRD-05VDC-SL-C relay that handles $30VDC$ and $250VAC$ and wiring it as:

Then when the doorbell button (outside flat) is pressed, the relay is triggered and the GPIO pin on the ESP is pullen down when the NO contact is closed.

ESPHome config

Using a binary_sensor component³:

binary_sensor:
  - platform: gpio
    id: doorbell_etage
    name: Doorbell Etage
    pin:
      number: ${pin_doorbell_etage}
      inverted: true
      mode:
        input: true
        pullup: true
    entity_category: ''
    device_class: ''
    publish_initial_state: true

We need to enable inverted since the pin gets pulled to $GND$ when the NO contact on the relay closes the circuit. Likewise, enable the internal pull-up (because the relay will pull the pin down) resistor to prevent the pin from floating.

CHANGELOG

References