I often times have difficulty getting to the buzzer of our building quick enough for FedEx and UPS, etc... or when I get visitors, they are sometimes inpatient and keep buzzing even though I'm still trying to get to the buzzer to let them in. I'd like to build a remote control to activate the "Door" (open door) button on my building's front lobby buzzer system. I imagine the "Listen" and "Talk" buttons are a bit more difficult, since you need to build audio and a microphone into a remote device.

Below are a bunch of pictures of the outside and inside of my buzzer system. This system is directly wired to the front door of our building. How can I integrate this with a remote control, a smart phone, or other remote device, so that I can press this button 30 feet away from the actual button?

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White mode button instructions taken from Amazon review:

There is a small, white mode button on the relay circuit board. With some experimentation, I have found 4 modes so far: (1) Push the mode button on the relay board once and the remote button once and you get a mode with the relay "on" (or "off" at the normally closed terminal) ONLY DURING THE REMOTE BUTTON PUSH. (2) Push the mode button twice and the remote button once and you get a mode that is "armed". When you push the remote the relay turns on (or off) and cannot be reset with the remote (alarm?). (3) Push the mode button 3 times and the remote button once and you get the usual latched on/off operation. Each remote button push toggles the relay state. (4) Push the mode button 4 times and the remote button once and you get an on (or off) state that lasts about 4 seconds and then goes off. (Use?) I couldn't find any more modes. If the relay board power is interrupted and turned back on, it reverts to mode(1).

  • \$\begingroup\$ Isn't the whole idea of such a system that you talk to the person to establish they are not unwelcome - surely your tenancy agreement will say something like this? \$\endgroup\$
    – Andy aka
    Oct 3, 2015 at 8:52
  • \$\begingroup\$ Normally I get visitors when I'm expecting someone, so in that situation, I don't even check who it is. I technically live in a condo building, so I might be breaking our bylaws in our condo association agreement, but I typically use my super skill and knowledge. \$\endgroup\$ Oct 3, 2015 at 9:29

2 Answers 2


What you want to get is a one channel, wireless remote control, like this one from Amazon:

enter image description here

The receiver has a relay contact output, that can be set to either operate momentarily as the remote button is pushed (which is what you want), or operate in a latching mode, on, off, on, off (which you don't want). This is selected by a small white mode button on the unit. One of the reviews explains the settings (apparently the documentation is not so good.)

You will want to wire the relay contact in parallel with the Door button contact on your existing unit.

The unit runs on 12V, I don't know if that voltage is already available from your box or not. Otherwise you will have to make provisions for it.

  • \$\begingroup\$ In case the link breaks in the future, this is the description: "1 Button 433MHZ Wireless RF Switch Relay Remote Control + Receiver Controller for Car Motor" \$\endgroup\$ Oct 3, 2015 at 9:04
  • \$\begingroup\$ I just received this in the mail from China. If I take some pictures, of the buzzer system (also above) and the device, in another question, would you have time this week or next to help me out? \$\endgroup\$ Nov 3, 2015 at 19:41
  • \$\begingroup\$ @MacGyver Well I never seem to have the time, but write to me at the email address on my website (softwest.com) and I'll see what I can do. No promises. \$\endgroup\$
    – tcrosley
    Nov 3, 2015 at 21:22
  • \$\begingroup\$ Used phone wire for the power source terminals (12V +/-), and soldered them to an adapter jack, which a wall wort plugs into. Then hooked up more phone wire to the Normally Open (NO) and Common (COM), and then pushed the white mode button four times so there's no security breach to our building's door lock. That way, when you hit the remote button, the circuit closes for 4 seconds, and then opens again. The default setting (for the white mode button) forced you to hit the remote button twice to close the circuit for a short period of time (between button pushes). Works like a charm!! \$\endgroup\$ Nov 22, 2015 at 4:22
  • \$\begingroup\$ Added the white mode button for the relay switch as an EDIT to my question. Taken directly from the Amazon review page per tcrosley. Clicks on the relay (in large black box) indicate when circuit opens or closes. \$\endgroup\$ Nov 22, 2015 at 4:24

It’s been a long time since this was asked, but I’m sure others still wonder how to do this. I found a much simpler solution than the other answer that doesn’t involve wiring: use a SwitchBot.

I have a SwitchBot and a hub setup and paired with the Amazon Alexa service. I created an, “Alexa, Open the front door” command. This triggers the SwitchBot to push the “DOOR” button for six seconds — replicating me pushing the button. Now I can yell at any Alexa in my house (or, the Alexa app on my phone if I forget my key) and buzz in a visitor.

Furthermore, I added an August smart lock to my apartment. Now, anywhere with an internet connection, I can let anyone into both my building and my apartment.


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