Door controller

[richardnhoffman]

Hello everyone,

I was just given a project from work to make a door controller using an arduino as the main microcontroller to operate a set of doors. It has been some time since I have worked on electronics and I am trying to find a simple way to operate the doors. All I need is an output to operate a relay and two feedback lines of when the door is open and closed. My biggest problem is operating the coil from 5V  to 36V unregulated and getting feedback from the 36V unregulated back to the pins of the arduino at 5V without blowing it up.

Output: Drive an unregulated 36V via 5V to a relay coil to ground. (opens door). The door is rigged to close when no voltage is applied to the relay.
Input: 36V unregulated from open door switch to 5V input pin.
Input: 36V unregulated from closed door switch to 5V input pin.
What components do I use to achieve this task?

Thank you for any feedback on this.

[Nusa]

Google "arduino relay circuit". The subject is well covered.

For input, I'd suggest an optoisolator as the safe approach. Google "arduino optoisolator input" for some ideas.

[NivagSwerdna]

There are plenty of ways to do this and I don't want to cramp your style.... but here is how London Hackspace control access... https://wiki.london.hackspace.org.uk/view/Door_control_system

Might give you some ideas.

It's got to be internet connected hasn't it.   

(ESP32, RPi, .... millions of possibilities)