I have a Aiphone GT-1C system and am trying to see if its possible to trigger the door release feature for my apartments intercom system.

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The pinout reads:

    IN  | OUT | IN | OUT |
    R R |R R  |B B |B B  |
    1 2 |1 2  |1 2 |1 2  |
   23.4v|23.4v| 0v | 0v  |

I measured the In and Out for R1/2 at 23.4v and 0v for In and out of B1/2. When I press the door release button (when its off not being called) all the pins go to 23.4v high. This leads me to believe that they are sending data over wire. I do have an oscilloscope that I could use but I feel like if it got to that point it would be over my head.

Is it easily possible to control the door release function via Raspberry pi?

(I was hoping it would just be turning a pin high and low but sadly it looks more complicated than that and its a 24v logic level)


So I emailed tech support asking if they had a dedicated door release pin and they responded with this:

An option switch dry contact closure can be used when connecting a dedicated strike circuit to the gray and black wires of the 6-pin option cable.

The door release button on the GT-1C triggers the Form C contact built into the back of the speaker module of the entrance. The tenant would need to press the Option button (the icon looks like a laptop monitor) to unlock their own unique door.

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  • If you're not a qualified [door technician/electrician/other-related-ician], I'd be very careful about trying this. Screwing around with door locking mechanisms is likely to do some very bad things to any future insurance claims.
    – goobering
    Aug 24, 2016 at 22:40
  • 2
    You could control a servo motor that pushed the actual physical button on the control pad. Aug 25, 2016 at 3:53
  • How do you know that b1 and 2 are input and output are you referring to one cable or 4 cables 2 in and two out or? Aug 27, 2016 at 16:48
  • This might be something you should explore on Electrical Engineering.
    – goldilocks
    Sep 13, 2016 at 17:38

1 Answer 1


So there was no real solution I found. I ended up taking the unit apart and soldering contacts onto the breadboard where the push buttons are and use a relay to emulate pressing the button. Works pretty well but still don't have a dedicated switch to open the door.

  • 1
    I have the same system, would you be able to show pics, and what hardware you went with?
    – Alex R
    Feb 17, 2019 at 22:05
  • Could you share a picture of the solution? Really interested in making this work myself Feb 2, 2021 at 11:54

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