YAGDM (Yet Another Garage Door Monitor)

Projects General Guidance
1

Hi there!

I am new to the whole world of Arduino and electronics, and I'm the kind of person who needs a "real" project to properly learn stuff. I don't know why, but countless "blinking LED"-like projects just don't stick in the sense I'd like them to.

Anyway - I've decided that my first real project is going to be a sensor for my garage door, since I can't see it from anywhere inside my house, and I'm sick of running out to see if the kids have left it open or not, hehe.

First off - I'm sorry if my questions has been answered countless times. I've been reading a lot of posts around the web about this kind of project, but haven't managed to decide what is the best solution for me, and how to go about it. Oh, and I'm sorry if I'm expressing myself poorly - English isn't my native language.

My current scenario:
My garage door opener is a fairly cheap model, that comes with nothing more than a remote, and a possibility to install a wired button. I currently have a button beside my front door, which is hooked up, and it's working like it's supposed to. To get the door moving, all that's needed is to connect two wires - I don't know if this is the way these things normally works, but that's how mine operates.

Anyway.
What I'd like, is a sensor on the door (a so-called window sensor/reed switch, maybe?) that can send a signal to my entrance hall when the door is open. To be honest, all I really need is a small 3mm. LED to light up when the door is open. That I could achieve with simple measures, without arduino at all - BUT - that's not much fun, is it?

So - ideally - this would be way better, and much more fun:
Ideally, I'd like a small, backlit LCD to display the message "Garage is open" when that is the case. When the door is closed, the screen can go off, or something. I'd like to send the signal from the garage wirelessly (maybe with xbee?) and it would also be fun if I could operate the door with a nice button, so that I could take down the ugly, old one I currently have.

Does this sound like a project managable by a beginner to you? If so - would you recommend the xbee? Would it work with Arduino Nano? I currently own a UNO R3, but would prefer if I could make this with a Nano, or something small, and mount the arduino permanently in a small box somewhere.

In addition: The motor on the door has got an issue sometimes. It happens maybe every two months or so. What happens is that when I press the button to open the door, nothing happens. I have to go in through the backdoor in the garage, only to find the motor light bulb (it's got a bulb that lights up a few minutes every time the motor's been active) blinking. I then have to unplug and plug back in the motor, and everything is fine again. Would it be possible to add a "reset" function in my project, to sort of do this also? A button or something? Just to cut the power to the motor, and then "plug it back in"?

I hope this wasn't too much nag from a beginner, and I would be forever grateful for any advice on my path, and also links to whatever components or relevant projects you know of.

Have a fantastic week end!

2

Sounds plausible enough. I'd suggest that you do it in stages though; start with just having an arduino controled button that opens the door using a relay connrcted to the wires that the original button uses. Then add a wired connection to your other arduino running the LCD, then go wireless.

Your last requirement is not so beginner friendly - to recycle the power on the device is going to involve switching mains, which is a dangerous proposition if you don't know what you're doing. In such cases, a powerswitch tail is often recommended to encapsulate the hazardous piece for you.

xBee is nice but expensive. There are cheap radio modules that would do the job too.

3

I have every intention of setting up such a monitor myself.

Having been in Amateur Radio since age 14 (or less, but that's when I sat the exam), I have an extremely healthy respect for what wireless communication are not appropriate.

You say you have a button adjacent to your front door to remotely actuate the door. This means you already have wires from that location to the door controller, in which case you can forget the Arduino, and the radios, and use those wires to do the indication.

It is the same situation as a light in the doorbell push - you have red and green LEDs wired back-to-back (or a 2-wire red-green LED) with a series resistor (220 ohm) across the button. At the other end, you can use either an H-Bridge or a relay to switch the polarity of current to the line according to the state of the reed switch. The power to this is fed through a 47 ohm 1W resistor (presuming 5V supply) across which is also a 1k resistor in series with a green LED and the base of a transistor which can trip the original controller circuit.

A further addition to this circuit could sense the blinking lamp and switch the supply to the indicator circuit to correspond. That this would interfere with the button operation does not matter as the controller does not work in this state until you reset it anyway.

4

Paul__B:
Having been in Amateur Radio since age 14 (or less, but that's when I sat the exam), I have an extremely healthy respect for what wireless communication are not appropriate.

You say you have a button adjacent to your front door to remotely actuate the door. This means you already have wires from that location to the door controller, in which case you can forget the Arduino, and the radios, and use those wires to do the indication.

Thanks for the input on this. I can see that wireless is not crucial in my case, but I really don't see the harm in it either. However, I am more than willing to use the wires that's already there, and I guess that'll simplify things also, so let's say I go for the wired version.

But I'd still like to use an arduino for this project. Maybe a micro or nano, if that's possible? And a LCD display instead of LEDs.

Paul__B:
It is the same situation as a light in the doorbell push - you have red and green LEDs wired back-to-back (or a 2-wire red-green LED) with a series resistor (220 ohm) across the button. At the other end, you can use either an H-Bridge or a relay to switch the polarity of current to the line according to the state of the reed switch. The power to this is fed through a 47 ohm 1W resistor (presuming 5V supply) across which is also a 1k resistor in series with a green LED and the base of a transistor which can trip the original controller circuit.

A further addition to this circuit could sense the blinking lamp and switch the supply to the indicator circuit to correspond. That this would interfere with the button operation does not matter as the controller does not work in this state until you reset it anyway.

This all sounds like something that might work, but it's a bit technical for me at my level of experience for the time being. But I'll take a note of it and show it to someone who's a bit more experienced than me in electronics.

Thanks for the input, guys!