🔔 ESPBell MAX detects ring (LED blinks) but binary_sensor not triggered in Home Assistant (HT9706)

[Anima1337]

Hi there,

I’ve connected an ESPBell MAX to my Balcom HT9706 intercom system and am facing the following issue:
🧩 Setup

Doorbell model: Balcom HT9706

ESPBell MAX board: [from PricelessToolkit]

Connected via:

    _**DB1 (BELL_A) → Pin 4 (GND) of HT9706

    DB2 (BELL_B) → Pin 1 of HT9706 (8V~ ringer signal)**_

When someone rings the bell, the bell icon LED on the ESPBell MAX lights up, meaning the optocoupler is getting triggered. ✅

However, Home Assistant shows “No Sound Detected” and the binary_sensor in ESPHome is never triggered.
🧪 Current ESPHome YAML:

esphome:
  name: espbell_max
  friendly_name: ESPBell Max

esp8266:
  board: esp12e

logger:

api:

ota:
  platform: esphome

wifi:
  ssid: "redacted"
  password: "redacted"
  manual_ip:
    static_ip: 192.168.178.138
    gateway: 192.168.178.1
    subnet: 255.255.255.0
  ap:
    ssid: "espbell_max_fallback"
    password: "fallback123"

captive_portal:

sensor:
  - platform: wifi_signal
    name: "ESP WLAN Signal"
    update_interval: 60s

  - platform: adc
    pin: A0
    name: "Batteriestand"
    update_interval: 60s
    filters:
      - multiply: 4.2

text_sensor:
  - platform: version
    name: "ESP Version"

binary_sensor:
  - platform: gpio
    pin: GPIO12
    name: "Klingel"
    device_class: sound
    filters:
      - delayed_off: 200ms

switch:
  - platform: gpio
    pin: GPIO5
    id: tuer_oeffner
    name: "Tür Öffner"
    restore_mode: always_off
    on_turn_on:
      - delay: 3s
      - switch.turn_off: tuer_oeffner

❗ Issue

Despite the LED blinking when the doorbell is pressed, Home Assistant does not receive any state change from the binary sensor. It always shows “No Sound Detected.”

I suspect that GPIO12 might not be the correct internal pin tied to the optocoupler. But I couldn’t find a clear schematic or reference in the documentation to confirm which GPIO is actually used.

✅ What works:

LED blinks = Optocoupler receives the signal

API + WiFi + OTA all work

ESP logs show no trigger on GPIO12

🔍 What I need help with:

Confirm which GPIO is used internally for DB1/DB2 signal detection?

Or is there something wrong in the YAML config that prevents the binary_sensor from detecting the change?

Thanks in advance for any help! 🙏
— Can



806-X-HT9706-2006-8806-8802+GV8802.pdf

VID20250714204820.1.mp4

[PricelessToolkit]

If you want to use ESPHome with ESPBELL-MAX, but why? You need to change its logic to "ESPBELL power is on = send message." DB inputs is not connected to any GPIO. default firmware sends mqtt payload when power is on. I recommend using the default firmware https://github.com/PricelessToolkit/ESPBell-MAX/tree/main/Code/ESPBell-MAX_MQTT_Auto_Discovery_Test

[Anima1337]

Hi again,

Thanks so much for your clarification regarding the DB input behaviour and the default power-on triggering method.

However, I’m currently trying to make this work via ESPHome, and here’s why:

In my setup, ESPHome has been more reliable than MQTT, especially when it comes to Home Assistant integrations, automations, and mobile widgets.

I need to be able to open the main entrance door at any time via Home Assistant, not just when someone rings. I’ve got a smart lock installed inside, so the ESPBell MAX needs to stay powered 24/7 for my automations and widgets to work consistently.

As far as I understand, with the default firmware, the ESP is only powered when someone rings the bell via DB1/DB2. That would completely prevent me from opening the door externally unless the doorbell was just rung, which makes it unusable in my case.

🔌 Power setup

I currently power the ESPBell MAX via 3.3 V using USB-C, with a battery backup to keep it always on.

So:
🔋 No power switching via doorbell ringing – it’s always on.
🛠 Problem

I connected DB1 to Pin 4 (GND) and DB2 to Pin 1 (8 V ringer) of my HT9706 intercom.

When someone rings, the bell LED lights up on the ESPBell MAX, so the optocoupler is definitely being triggered.

However, since DB1/DB2 is not tied to any GPIO, ESPHome receives no input – so nothing happens in Home Assistant.

❓What I need

Is there any way to fix this with ESPHome, either:

through YAML configuration (unlikely if no GPIO is connected), or

through a small hardware mod (e.g. soldering a jumper from the optocoupler output to GPIO12 or GPIO14)?

If you can help me identify the right test point or leg of the optocoupler to wire to a free GPIO, I’d be happy to do that and report back.

Thanks again for all your work – I’d love to keep using ESPHome in this setup.

Best regards,
Can

[Anima1337]

I've been considering buying a separate ESPBell LITE for the door opener, and using the ESPBell MAX just for the doorbell detection — even if it's a more expensive solution.

The reason is: I really need the ESP controlling the door opener to be always powered, so I can open the door at any time, even when no one has rung the bell. At the same time, I still want to detect when someone rings the doorbell.

I noticed that the ESPBell LITE also has BELL input pins, but it only accepts 3.3V power and runs permanently — so I was wondering:

How does the ESPBell LITE handle doorbell detection in this case?
Can I still use those BELL pins to detect the ringing, even while it's running continuously on 3.3V?

Would love some clarification on this before deciding how to proceed.

[PricelessToolkit]

ESPBell LITE has the same DB input and 1 SSR relay as the MAX version, and it requires a 5V power supply, not 3.3V.

So ESPBell-lite will work for doorbell detection and door opener at the same time.

[Anima1337]

Thanks for the clarification!

Just to make sure I understand it correctly:

I should get the ESPBell LITE

Power it via a 5V supply

Then I can connect:

    DB1 to GND

    DB2 to the doorbell hot line (e.g. from Pin 1 of my HT9706)

The board will then stay permanently powered

And I can still use the door opener via the relay, as usual

Plus, I’ll be able to detect when someone rings the bell in ESPHome, even while it’s always on?

If that’s all correct, one last question:

Which GPIO is internally connected to the DB input on the ESPBell LITE?
(So I can configure it properly in ESPHome)

Thanks again! This would be the perfect solution if everything works as described.

— Can

[PricelessToolkit]

GPIO4

https://github.com/PricelessToolkit/ESPBell-LITE/tree/main?tab=readme-ov-file#esphome-yaml-configuration

[Anima1337]

Thank you so much for your patience and willingness to help me! I really appreciate it! I know that you do not have to do this. Especially in your free time. I am much obliged and appreciate your work! (: Will order the ESP Lite and hopefully get everything sorted since I got the wiring figured out now and a GPIO Pin for the ESP Lite that should work in ESP Home as well <3

[Anima1337]

Hi again 😊

Quick follow-up:

I'm currently powering the ESPBell Lite via the 3.3 V UART pin, but I'm seeing that the relay stays constantly ON (closed), even with restore_mode: ALWAYS_OFF in ESPHome.

Is that because of the 3.3 V UART supply? (I will use the 5V import as per instruction for the final setup, don't worry).

I’d like to confirm:
→ Should I switch to powering via 5 V VCC instead, e.g. with a USB-C breakout board?
→ Would this resolve the relay defaulting to closed?

I’m trying to make sure that the relay is normally open and only closes when triggered via YAML logic (e.g. 3s to open door), but right now it acts inverted.

Thanks again for your help!

`esphome:
name: espbell_lite
friendly_name: ESPBell Lite

esp8266:
board: esp12e

logger:

api:

ota:
platform: esphome
password: !secret ota_password

wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
manual_ip:
static_ip: 192.168.178.147
gateway: 192.168.178.1
subnet: 255.255.255.0
ap:
ssid: "espbell_lite_fallback"
password: "fallback123"

captive_portal:

WLAN-Signal

sensor:

• platform: wifi_signal
  name: "ESP WLAN Signal"
  update_interval: 60s

Firmware-Version anzeigen

text_sensor:

• platform: version
  name: "ESP Version"

Klingelerkennung über GPIO4 (DB1/DB2)

binary_sensor:

• platform: gpio
  pin:
  number: GPIO4
  mode: INPUT_PULLUP
  name: "Klingel"
  device_class: sound
  internal: false
  filters:
  • invert:
  • delayed_off: 1000ms

Türöffner über GPIO5 (Relais SSR1)

switch:

• platform: gpio
  pin:
  number: GPIO5
  inverted: true #Doesnt matter if inverted or not
  id: tuer_oeffner
  name: "Tür Öffner"
  icon: "mdi:lock"
  restore_mode: ALWAYS_OFF
  on_turn_on:
  • delay: 3s
  • switch.turn_off: tuer_oeffner
    `

[PricelessToolkit]

Each relay "leg" has 2 paralel wire, so first 2 wires are connected together and the second pair too.

[PricelessToolkit]

SSR Relay connected directly to ESP, so if the control pin is High the relay is "closed"

[PricelessToolkit]

Can you take a photo of the connector where the pins touch the PCB? If it's always closed, there's a short circuit. If there's no short circuit, it's magic.

[Anima1337]

VID20250723212404.1.mp4

[Anima1337]

I also tested your example code just in case

`substitutions:
name: ESPBell-LITE

esphome:
name: espbell-lite
name_add_mac_suffix: false
project:
name: pricelesstoolkit.espbell-lite
version: "1.0"

esp8266:
board: esp12e

dashboard_import:
package_import_url: github://PricelessToolkit/ESPBell-LITE/Code/ESPHome/espbell-lite.yaml@main
import_full_config: true

Enable logging

logger:

Enable Home Assistant API

api:

ota:

• platform: esphome
  password: "password"

wifi:
ssid: !secret wifi_ssid
password: !secret wifi_password
fast_connect: true
power_save_mode: none

Enable fallback hotspot (captive portal) in case wifi connection fails

ap:
ssid: "${name} Fallback Hotspot"
password: "password"
ap_timeout: 10s

captive_portal:

sensor:

• platform: uptime
  name: "${name}"
  id: uptime_seconds
  update_interval: 60s

• platform: wifi_signal
  name: "${name} WiFi Signal"

binary_sensor:

Doorbell Sensor

• platform: gpio
  pin:
  number: 4
  #inverted: true
  name: "DoorBell"
  icon: "mdi:bell"
  filters:
  delayed_on: 100ms

• platform: status
  name: "${name} Status"

switch:

• platform: gpio
  pin: 2
  id: LED
  restore_mode: ALWAYS_OFF
  inverted: True

Door Lock Opener "Momentary Switch" Keeps SSR ON for 1.5s.

• platform: gpio
  pin: 5
  id: Lock
  name: "Lock"
  icon: "mdi:lock"
  restore_mode: ALWAYS_OFF
  on_turn_on:

  • switch.turn_on: LED
  • delay: 1500ms
  • switch.turn_off: Lock
  • switch.turn_off: LED

• platform: restart
  name: ${name} restart`

[Anima1337]

No short circuit

[PricelessToolkit]

1. Combine black and red together as one wire
2. Combine grey and brown together as one wire

In the video, the "grey and brown" are the same leg of the relay :)
So it will be 2 pairs each containing 2 wires, treat each pair as 1 leg of a relay

[PricelessToolkit]

Or you can take one wire from each pair like "red and grey" or "black and brown"

[Anima1337]

I'm a dumbass😂
I read on your website that's it's 1 Relay, only saw one IC for it yet still thought it's 2, just like the max, because it had two pairs each labeled Relay.
Thanks for your help yet again 🫶🏼
May I ask why there's two pairs for each leg of the relay?

[PricelessToolkit]

Current handling + for some interphones its preferable have 2 pair

[Anima1337]

Alright, thank you (:
Will solder all pairs to the intercom tomorrow (:
Love your work and support!