11/11/14: Prepare yourself for disappointment. I started this project almost two years ago. It worked at first and failed shortly after when the cheap power supply I was using overheated. I never finished the blog entry anyway, so I wouldn’t bother continuing to read this if I were you. Since then I’ve turned it into a wireless version that has the added bonus of ringing the doorbell whenever I plug or unplug something from the outlet on the opposite side of the wall. I have plans to finish this project and write about it at some point. Perhaps I’ll break character and follow through.
1/28/13: First Post, in progress, will be finished within a day or two.
A couple of weeks [my wife says months] ago my doorbell stopped working. I’d already replaced the button once so I was a little annoyed, but after replacing it again I realized that the problem was different this time. I suspected that the transformer was bad so I crawled into the attic to test it.
Mine was located directly above the hall closet where the ding-dong-box lives. I took voltage readings on the line voltage wires going into the transformer and they were fine which means it was getting power. The two low voltage wires coming out of the transformer, however, read 0V rather than the proper 16 Volts AC. It looked fine on the outside but you can’t judge a transformer by its windings… or something. I took apart the box for
good measure fun, and it was a good thing I did.
I’ll briefly explain how these work. There are two flat metal xylophone-type bars (one for “ding” and one for “dong”) and two steel rods (plungers) attached to springs. The plungers each sit inside a coil of wire. When the doorbell is pressed, power is fed through the transformer and around the coils. This creates a tiny magnetic force that pushes the plungers out of the coils. One plunger hits a bar while compressing a spring. Ding. The other hits a little sponge while also compressing a spring. Pfft. When the button is released, the magnetic field goes away. Ding goes back home and the second plunger is pushed into the other bar by it’s compressed spring. Dong.
When I opened the box to check out this nifty little electro-mechanical marvel, it was clear that Ding’s coil had been damaged. I’m not sure what happened specifically, but now everything needed to be replaced. I tossed the transformer and saved the remaining undamaged parts because I need them for another project that I haven’t thought of yet.
Time to go shopping. A new transformer is about $12 and a new doorbell assembly like the dead one was another $20. A wireless doorbell was about $30 which means I could use the “saving money” excuse for a project . I prefer the sound of the mechanical version over the fake digital version, but the digital version would allow me to tinker a little more and I was starting to get some ideas. I bought the crappy wireless one and brought it home.
My wife had already purchased a lovely antique copper doorbell with a lighted push button which looked much better than the cheap white plastic version that came with the wireless setup. I knew that there was a fairly simple little hack that would allow me to use the pretty button to control the cheap one that sends the signal to the receiver which plays the fake ding-dong sound. As I’m playing around with the nice one, I notice that there’s an LED inside with a happy little surprise. I was expecting it to be a tiny little SMD LED (If there’s a light on your keyboard or cell phone, it’s an SMD LED) because there wasn’t a ton of space in the little push button. Instead it turned out that the LED was your standard white 5mm dome-shaped style, or T1-3/4 which you might recognize as the “traditional” LED.
This is good news because I knew that it would be pretty simple to swap it out with a super bright blue LED which I happen to have a surplus of. It’s not any different functionally, I just thought it would be fun. What would be even cooler than that? An RGB LED. RGB LEDs are actually three separate LEDs all in one package that looks almost exactly the same. The colors can each be turned on at different brightness levels (sort of- don’t ask) which, combined, give you any color you’re little heart desires. The problem is, a single-color LED has two pins and an RGB LED has four, which means I wouldn’t be able to just swap out the LEDs and put it back together. You also need a programmable micro controller if you want to have control over the color.
I will definitely need to create a dedicated page about my experiences with Arduino. There’s too much to talk about without this post going in a totally different direction. One of the best things about it, however, is that you really don’t need to know much to be able to use one. If you ever graduated elementary school, I promise this is within your grasp. Here’s what you need to know about Arduino for this project:
1) An Arduino like the one I use in this project is a circuit board with a “computer chip” that can be programmed by the user. All you need is the board, a USB cable, and a computer.
2) You do not need to learn how to program a computer. The software that’s used for the programming makes it much easier to do than you might think, but if your project has already been done by somebody else (like this one), you can just copy the code they used, paste it into your Arduino software, and hit the upload button. If you decide you want to learn more about the programming down the road, the are millions of resources out there to do so, and this blog will be one of them.
3) What’s the gist of it? Here’s one of the most basic examples: Let’s say you have a push button (INPUT) and an LED (OUTPUT) connected to an Arduino. Using just a few lines of code, you can tell the Arduino to turn the LED on every time the button is pressed. It’s even easier than it sounds. The code I’m using here is a little more complex, but don’t worry. All you will have to do is copy and paste. I’ll explain a little more when we get to that point.
I’m going to take a break from trying not to scare you away from electronics and dig into making something. Let’s do it Instructables style. A list of tools and materials can be a little boring, so my recommendation is to read through the project and if it sounds like something you would be interested in doing, click here for the full BOM (Bill of Materials), etc.
Note: If you are completely new to electronics, this project is probably not a good place to start, but I’m going to break it down anyway. If you have never installed a light switch or receptacle, this is probably not a good place to start, but I’m going to break that down too. If you have a little experience in either area, this is probably a waste of your time and money. There’s no getting around that. If you like learning things or blinking lights or reading weird blogs, this might be for you. If you really want a color changing doorbell and want to build it yourself, as far as I know, there is no better place on the internet to learn how then right here. Congratulations.
Here we go (finally)…
First, let’s start with a little prep work. Remove your old doorbell and accidentally feed it to your dog. Otherwise, save it somewhere for a future project. It’s the sort of thing that will come in handy if you want to play with this stuff more down the road. We need to make sure the new doorbell is going to fit in place of the old one. It’s not going to take up any more space after the modification, so just see if it fits in the hole the wires are coming through. If the hole isn’t big enough, shove the wires in and out of the way as much as you can. Even if you aren’t planning on reusing these wires, you (or your landlord, hehe) might want to in the future. If the drill bit catches the wires it will wrap around the bit and turn into a big pain and you’ll feel bad about yourself.
Once you know your new push button will fit, check the other side of the wall. This is where your situation is likely to be somewhat different than mine.
Originally, I planned to drill straight through the wall and install a box there, directly behind the push button, which would put it about 8″ below the porch light switch on the inside. After I drilled the hole (oops), I realized that it would look a little too weird there for my taste and a lot too weird there for my wife’s [much better] taste.
A better option was to put it closer to the floor level where there was already a receptacle. I knew it was in the same bay between the wall as the push button so it wouldn’t be too hard to pull the wiring through. It would also make more sense to have a device at a standard height, although it won’t look too standard when I’m done with it.
We’re about to pull out that receptacle so here’s the obligatory self-release of liability:
1. Jump in the shower with all of your clothes on. You need to be as wet as possible for this.
2. Before you even think about touching the circuit breaker, hit the receptacle with a sledge hammer. Rip it the rest of the way out with your wet/bare hands.
3. Rip the insulation off the ends of the wires with your teeth.
4. Stick the white/neutral wire up your left nostril. Stick the Black/hot wire up your right nostril.
5. Stick your fingers in your ears.
6. Take a deep breath, hold it, and cross your eyes.
7. Blow as hard as you can. If you fart lightning, you did it right.
If you’re a big chicken but still want a color changing doorbell, skip the previous steps and continue below.
Using a voltage tester, multimeter, or table lamp, check to see if your receptacle has power. It probably does. Find the right circuit in your breaker panel if you can. If it’s not labeled you may have to use trial and error. If you’re the one who cleans the toilets in your household, make sure nobody is using the bathroom when you start flipping breakers. Tricks of the trade, folks. After you find the right breaker, test your meter on a hot circuit again just to make sure it’s still working. Get a sharpie and write the circuit number on the back of your new cover plate in case you need it later. Also write which receptacle belongs to that circuit in the panel. You will thank yourself when you go back in a year and see “Tacky-Waste-of-Time-Blinky-Doorbell Circuit” next to #12. Breaker panel manufacturers don’t take personal labeling preferences very seriously, so you may only have space to write “Front Door Rcpt”. Do this with every circuit in your house while you’re at it. I know I will be glad I did when I get around to it myself in 8 or 9 years.
Unscrew the receptacle and pull it as far out of the box as you can. Note which wires are going to the hot and neutral sides of the recptacle, then disconnect them. The hot side should have brass-colored screws with black wires attached and the neutral side should have chrome-colored screws with white wires attached. This is definitely not always the case, so do a little Googling if yours looks different or you’re still unsure what to do.