How to smartify my intercom?

Pangslinger · January 20, 2024, 6:49pm

Greetings fellow Home Assistant enthusiasts and tinkerers,

I would like to embark on a project to make my intercom smart. While I have some knowledge in software, my expertise in the hardware aspect of home automation tinkering is somewhat limited. Therefore, I’m reaching out to this knowledgeable community for guidance and insights.

In my research, I came across a project where someone integrated smart features into their Urmet 1133 intercom (details available at ilfuriano’s GitHub). Although it’s a great reference, my requirements and setup might differ slightly. Additionally, I find myself struggling to decipher their circuit diagram fully as I am just starting to learn the hardware side of things with this project.

My goal in making the intercom smart is threefold (with the last objective being somewhat less crucial):

Integration with Home Assistant (HA) to detect the status of the LED (marked in red), which indicates whether the gate is open or closed.
Capability to remotely open the gate through HA, corresponding to the functionality of the button marked in blue.
Ideally, I’d like HA to be alerted when the bell rings. I believe the bell mechanism is linked to the handset (highlighted in green).

I have several queries to ensure a successful implementation:

What specific hardware components will be necessary for this project (I guess an ESPhome?) ? And how do I find out? Do I need to measure some currents?
How should these components be integrated within the existing circuit layout?
Is it essential for me to acquire soldering skills before attempting this project?
Can the existing electrical setup of the device be utilized to power the ESPhome, or is an external power source required?
Are there any other considerations or potential challenges I might have overlooked?

Your expertise and advice would be immensely appreciated in helping me navigate my very first HA hardware project.

Thank you in advance for your support and insights!

Best regards.
P.

Fallingaway24 · January 21, 2024, 12:29am

I will say, you werent scared to go big on your first project! I can tell you put some time into it and asked good questions.

As far as your goals. If you dont have a multimeter, youre definitely going to need one here.

Using the state of the led as a binary sensor.

This is an easy one. You need to check the voltage that powers the led. This will determine if you can tie into the 2 led wires and run it directly to an esp board or if yoir going to need to regulate the voltage up/down

Remotely open the gate from HA.

This is a simple one too. Very similar to doing the led. Tie a pair of wires onto the switch wires. I assume the voltage here will be 12/24VDC so youll likely need a relay here and the switch and relay will work in parallel so one isnt interfering with the other.

Alerted when bell rings.

Similar process again. Tie into the 2 wires that trigger the bell. Depending on the voltage here, you have a few options. The simplest would probably be a voltage sensor. These are just small pcb boards and when a positive voltage is applied, it will send either a High or Low signal back to the esp board and its the equivalent of an On/Off sensor that HA can use.

What hardware will you need.

That kind of depends on where you land with the voltages you come up with after measuring them. One concern you didnt address is how far is this gate controller from the house and the wifi network? Do you get wifi coverage out there? If you do, what is the box made of that houses the gate electronics and presumably your modifications? Some metals will absolute block wifi signals. If this is the case youll need an esp board with an external antenna.

How should the components be integrated? Being so new to this, id suggest keeping it simple. Take advantage of open spaces to mount components. Id get some wire/cable organizers for neatly running wires.

Soldering skills…

Soldering is actually very easy. There are all kinds of resources to learn and you can buy practice kits on amazon. Since almost all this project is just pigtailing the existing wires on the button, led and such. You could just cut the wires in the middle, strip the insulation back a lille bit on both cut ends then add your wire and wire nut all 3 ends together. Unless you think this is your first and last project, soldering isnt optional its a must. Its very common for esp boards, components, sensors, etc to come with looae male and female headers and they need soldered on.

Power.
Yes, absolutely. If you’ve got a 12 or 24vdc in there, thats perfect. Even if youve only got access to 110/220AC, you could use the equivalent of a cell phone charger which steps down mains AC and outputs 5.0 VDC which is exactly the voltage you need.

Fallingaway24 · January 21, 2024, 12:43am

Looking closer at the picture, the 2 wires for the led go up and into a connector box. You can just loosen those screws and run a second wire out of the +/-
The switch is the same. Its got screw terminals on it. Loosen them and add a wire out of each terminal. Easy

Pangslinger · January 21, 2024, 9:25pm

Thank you very much for taking the time to write such an elaborate answer @Fallingaway24 !
You helped me to gain some optimism on my endeavour
I got me a multimeter and tried to measure the voltages in a hurry but couldn’t get clear readings. I will try again with more time.

The gate is approximately 100 meters away from the house without any wifi, so I hoped to just install the ESPhome dirtectly into the intercom.

I will let you know about my results!
Thanks again.
Best, P.

Fallingaway24 · January 21, 2024, 11:24pm

Ys switches can be confusing because there are several ways you can wire a switch so you may not see a voltage when you measure the 2 wires from it. If you arent getting a voltage then they are likely the same, for example one could be a posotive 5v and only when the switch is pressed is 5v allowed to pass into the second wire. The opposite is also true, instead of a positive voltage going to the switch, they can both be grounds. ll you can really do is find where the dc power comes in and then you have a known +/- use the use the known ground to test from and see if you get a voltage on one side of the switch and if not do the opposite. Use the known posite on the meter and test both sides of the switch with the ground probe on your meter.

Fallingaway24 · January 21, 2024, 11:35pm

Did you get a voltage at the led? I thought about it later and it slipped my mind that led’s use pwm signals and im not positive if the pwm voltage can be measured with a meter or if some meters can and others cant.

I dont mean any offense here but, you do know how to use your meter and which settings you need to use for different things? Some meters you have to change how the probes plug in depending on if your measuring AC lr DC and some you dont.

Pangslinger · January 22, 2024, 7:02am

I am indeed no expert in using a multimeter xD. So I testet both AC and DC. For DC the voltage fluctuated a lot (though as I read this might be normal, due to pulsing) for AC it was stable when attaching it to the wires. However, I was a bit confused because the multimeter showed even voltages when not beeing attached to anything, but I do not know whether this is due to electricity fields or the multimeter being cheap. I think this will have to wait until the weekend when I am not in a hurry.

And yes indeed, the voltage didn’t change for the LED when it was turned on or off! It always showed something around .45 mA. Whereas the button voltage shortly jumped up to 1.x mA when being pressed.

edit ps: I a not even really sure whether it was mA I saw. I will check again.

Pangslinger · February 22, 2024, 10:30pm

I’ve done it. Yippie!
I created a solution using an ESPHome Arduino (specifically, a NodeMCU Amica Module V2 ESP8266) and a relay module (5V KY-019 High-Level Trigger). It took a bit of effort, but the solution turned out to be straightforward. Btw. arduino and relais fit perfectly into the phone. However, the power for the arduino comes from outside.

I connected the relay in a way that it works alongside the button (to the Normally Open and Middle Pin connections) and then hooked it up to the microcontroller (to the 3.3V power, ground, and GPIO2 pin). This setup allows me to activate the button either manually or through a smart home platform called Home Assistant.

I also connected the two wires of an LED light to the microcontroller (to the ground and GPIO4 pin). Even though the LED only requires 2.3V to work, it functions perfectly, helping me know if the door is open or closed.

Finally I connected a digital noise sensor. This is not a perfect solution, as it is also activated by other loud noises. But as I only want to be notified when we are not in the house this doesn’t matter.

I honestly did not care about good cable management, as it is hidden anyway.

The blue and green LED-color is due to the NodeMCU and the sound sensor. As a true gamer I am however happy with this unexpected result. RGB ftw.

Here’s the code I used for setting up the ESPHome:

esphome:
  name: interkom
  friendly_name: interkom

esp8266:
  board: nodemcuv2

# Enable logging
logger:

# Enable Home Assistant API
api:
  encryption:
    key: "redacted"

ota:
  password: "redacted"

wifi:
  networks:
  - ssid: "redacted"
    password: "redacted"
  - ssid: "redacted"
    password: "redacted"

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "redacted"
    password: "redacted"

captive_portal:

switch:
  - platform: gpio
    id: open_relay
    name: "GateOpener"
    restore_mode: ALWAYS_OFF
    pin: GPIO2
    on_turn_on:
      then:
        - delay: 1000ms
        - switch.turn_off: open_relay

binary_sensor:
  - platform: gpio
    pin: GPIO4 
    name: "GateStatus"
    filters:
      - delayed_on: 500ms #Just to besure
  - platform: gpio
    pin: D7
    name: "BellRings"

Fallingaway24 · February 24, 2024, 1:35pm

Sweet! I wont lie, im kind of disappointed in you… the least you could do for me in return is post some DIY porn pics to go with it! Show some long wires and but naked relays!

Did you want to also track the state of the physical button? Was an led supposed to light up or something? I cant remember.

Pangslinger · February 24, 2024, 2:05pm

Hahaha, I won’t let you down!. I am still waiting for two things to arrive in the post:

a 5m usb cable for proper cable management
a noise sensor to detect whether the intercom bell is ringing.

Then I have figured out everything I wanted (and will post some pics): 1. I can open up the gate wirelessly. 2. I can see in HA whether the gate is open or not (which has only been shown via the LED until now). 3. I will be notified on my mobile, when someone rings the bell (which will be helpful, when I am in the garden).

Btw. I also created the best automation ever: When I am at home, the gate will now open as soon as I turn on the car (tracked by my mobile connecting to the car).

I’ll keep you posted.

Fallingaway24 · February 24, 2024, 2:53pm

Oh nice! Dont forget those pics because, I know what you did last summer!!

Pangslinger · March 1, 2024, 8:25am

Behold! The final (at least as final as one can get in home automation ) solution is there. I’ve added the sound sensor and posted some pics in the solution post above!
Thanks again for your help and motivation!

Fallingaway24 · March 1, 2024, 8:38am

Nice! Was this your first DIY project? Even though your lack of wire management sent me into an OCD panic, you did a good job!. Something tells me got DIY hooked and you’ve got plans for more projects in the future…

Pangslinger · March 1, 2024, 9:29am

What gave me away? I’ve already bought five more NodeMCUs and an indefinite number of various sensors.

Fallingaway24 · March 1, 2024, 9:51am

Oh dang! You really did get hooked. These arent known as the highest quality sensors but, these “Arduino sensor kits” on Amazon or wherever you shop, theyre a good bargain and gives you sensors to work with and learn with. These gas sensors are fun to use too and you can get halfway devent readings from as well.

Depending on how deep down the rabbit hole you get sucked into this, Id suggest also learning the other half of this hobby, the electronics side… I have this book among many Simon Monk book, he has a good way of explaining things so they make sense and dont overwhelm you. This is a good beginner level book and the topics are broad while not getting too far into the weeds with electrical theory and fun calculus eqations. I can send you some photos of inside my book if youd like to see some of it.

https://www.amazon.com/dp/B0CMSQY5L7/ref=sspa_mw_detail_0?ie=UTF8&psc=1&sp_csd=d2lkZ2V0TmFtZT1zcF9waG9uZV9kZXRhaWw&th=1

Pangslinger · March 2, 2024, 4:42pm

Thanks a lot recommendation. I’ve put the book on my wishlist!

anestef · May 2, 2024, 12:30pm

hello could you help me with this?i have the same intercom as you
but how to get notify then someone ring the bell?
could you tell me the pins for this?
thanks

Pangslinger · May 2, 2024, 12:56pm

Hi,

The bell-ringing notification operates through the sound sensor as previously described. Since the sensor can also pick up other loud noises, I’ve implemented a solution using a helper that recognizes several consecutive loud sounds, which are indicative of the bell ringing.

You will need to determine the appropriate pins yourself, as this depends on your specific system and sensor. Moreover, I prefer not to reopen the intercom at this time.

Below is my Home Assistant code for your inspiration (Klingel means Bell in German):

alias: "Notification: Klingel"
description: ""
trigger:
  - platform: state
    entity_id:
      - binary_sensor.interkom_klingelstatus
    to: "on"
condition: []
action:
  - service: input_number.increment
    metadata: {}
    data: {}
    target:
      entity_id: input_number.klingelcounter
  - delay:
      hours: 0
      minutes: 0
      seconds: 2
      milliseconds: 0
  - if:
      - condition: numeric_state
        entity_id: input_number.klingelcounter
        above: 3
    then:
      - service: input_boolean.turn_on
        metadata: {}
        data: {}
        target:
          entity_id: input_boolean.klingelbinary
      - service: input_boolean.turn_off
        target:
          entity_id:
            - input_boolean.klingelbinary
        data: {}
      - service: input_number.set_value
        metadata: {}
        data:
          value: 0
        target:
          entity_id: input_number.klingelcounter
      - device_id: ödjsfnaeökdsjfnawsdlökjfnasdlkfjn
        domain: mobile_app
        type: notify
        message: Klingeling 4 real!
      - service: automation.turn_off
        metadata: {}
        data:
          stop_actions: true
        target:
          entity_id: automation.notification_klingel_2
    else:
      - service: input_number.set_value
        metadata: {}
        data:
          value: 0
        target:
          entity_id: input_number.klingelcounter
mode: parallel
max: 10

as well as a second automation

alias: "Notification: Helper Klingel 4 Real Turn on when off"
description: ""
trigger:
  - platform: state
    entity_id:
      - automation.notification_klingel_2
    from: "on"
    to: "off"
condition: []
action:
  - delay:
      hours: 0
      minutes: 0
      seconds: 2
      milliseconds: 0
  - service: automation.turn_on
    metadata: {}
    data: {}
    target:
      entity_id: automation.notification_klingel_2
mode: single

Overall Workflow

Automation 1 deals with the bell ringing: tracking how many times a sound is detected, resetting, and sending notifications if it’s likely a bell ringing sound (due to the consecutive noises). Please note that this automation runs in parallel mode!
Automation 2 ensures that the critical automation notification_klingel_2 is always active, potentially to avoid situations where it remains disabled after being turned off. This is a fail-safe mechanism to keep the system responsive. I am sure there are better ways to do this, but this works for me.

anestef · May 2, 2024, 1:23pm

thanks for answer
can this be done without sound sensor?
i have ewelink sonoff relay can this be done throw this?
and could you share link for your sound sensor?
also beacuse i like sonoff can it be done somehow throw this?

Pangslinger · May 2, 2024, 1:25pm

I have no idea how. However, I am no expert. If you find out. let us know! Good luck!