Darren Lewis’ parents both have a difficult time hearing the doorbell. He experimented with an off-the-shelf flashing light, but found that could only really be seen when they were in the room—an obvious problem. In response to this, Lewis decided to make his own system that flashes multiple house lights at the same time.

His device uses an Arduino Nano to detect the stock doorbell speaker voltage. When a press is sensed, it then activates a RF light switch via a modified remote, using an output pin and opto-isolator to substitute in for the normal button press. 

It’s a clever hack, and certainly one that will certainly help alleviate doorbell frustration in the future!

Smart Doorbell is the name of the project for a new tutorial created for Intel Edison. It’s a motion detecting doorbell, that senses when someone is near the door(bell) and via a webcam sends a picture of the person approaching the door to a web address while playing a sound.

“Motion detecting video streaming doorbell“, a medium-advanced level tutorial, is intended to be a good starting point for building basic IoT devices. You’ll learn how to use a webcam to detect motion: when activated, the device will play a greeting, take a photo and email it to someone to let them know who is at the door.
Take a look at the video to see how it works and follow these steps to make yours:

One day, [Samy]’s best friend [Matt] mentioned he had a wireless doorbell. Astonishing. Even more amazing is the fact that anyone can buy a software defined radio for $20, a small radio module from eBay for $4, and a GSM breakout board for $40. Connect these pieces together, and you have a device that can ring [Matt]’s doorbell from anywhere on the planet. Yes, it’s the ultimate over-engineered ding dong ditch, and a great example of how far you can take practical jokes if you know which end of a soldering iron to pick up.

Simply knowing [Matt] has a wireless doorbell is not enough; [Samy] needed to know the frequency, the modulation scheme, and what the doorbell was sending. Some of this information can be found by looking up the FCC ID, but [Samy] found a better way. When [Matt] was out of his house, [Samy] simply rang the doorbell a bunch of times while looking at the waterfall plot with an RTL-SDR TV tuner. There are a few common frequencies tiny, cheap remote controls will commonly use – 315 MHz, 433 MHz, and 900 MHz. Eventually, [Samy] found the frequency the doorbell was transmitting at – 433.8 MHz.

After capturing the radio signal from the doorbell, [Samy] looked at the audio waveform in Audacity. It looked like this doorbell used On-Off Keying, or just turning the radio on for a binary ‘1’ and off for a binary ‘0’. In Audacity, everything the doorbell transmits becomes crystal clear, and with a $4 434 MHz transmitter from SparkFun, [Samy] can replicate the output of the doorbell.

For the rest of the build, [Samy] is using a mini GSM cellular breakout board from Adafruit. This module listens for any text message containing the word ‘doorbell’ and sends a signal to an Arduino. The Arduino then sends out the doorbell code with the transmitter. It’s evil, and extraordinarily over-engineered.

Right now, the ding dong ditch project is set up somewhere across the street from [Matt]’s house. The device reportedly works great, and hopefully hasn’t been abused too much. Video below.

hey gang, does anyone know if it's possible to use mains AC as a switch for the 'duino?

A little background:

Calculon is working on a project that he hopes will take advantage of his doorbell's AC power. He wants the old-school analog doorbell switch to activate a function on his arduino instead of firing off a solenoid in the door chime. Is this possible with some sort of voltage divider? He doesn't need to measure the current, voltage, phase, or anything liek that, he just needs to sense on/off like a pushbutton. He assumes the initial doorbell voltage will be 120V.

read more

[Piet] wrote in to tell us about his hack that allows for his front gate to be opened without a key. Unlike this hack that we featured in August, you don’t need a subway pass, just a good memory. As explained in his article (and the video after the break) if the proper sequence of doorbell rings is input, the gate unlocks itself.

For hardware a [mehduino] is used to take the doorbell input and decide whether or not the “secret knock” has been achieved. The door can be unlocked remotely via a button on the processor. Reprogramming the code is achieved by simply holding the program button while the code is entered on the “remote ringer” button.

Be sure to check out the video after the break to see this lock in action. The housing application may not be exactly what you expect. Also of interest, is that in true hacker fashion, the bare processor is hanging by a hook on his wall!

Even if you live in a dump this quick build will make your doorbell sound high-class. The new rig uses a crystal goblet to alter you of guests at the door. We suppose the room-silencing sound of flatware on a wine glass does make a great attention getter.

For [Tobias] the hardest part of the build was getting his wife to sign off on it. But he says the 1970′s era original was looking pretty shabby, which kind of made his argument for him. It took just two hours to develop and install the replacement. It uses a servo motor with an articulated striker to ping the glass which is hanging inverted between two pegs. The original AC transformer (which are most often 16V) was used to power the Arduino. He built a simple rectifier along with a big smoothing capacitor to make sure the Arduino doesn’t reset when voltage dips. Although it’s not mentioned in his comments, we’d bet the doorbell wire has been rerouted to connect directly to the Arduino, rather than remain patched into the power loop.

Don’t miss the clip after the break to hear how great this thing really does sound.

Ever wonder who comes to your door during the day while you’re gone?  Here’s a simple DIY project to answer that question.  Every time someone rings your doorbell, you’ll receive a text message containing a photo of the person.  The system can also be setup to automatically take photos based upon motion detection instead of a doorbell press.

When someone rings the doorbell, the Arduino instructs a camera to take a picture. It then also sends an email to your smart phone notifying you that someone is at the door.  If you’re nterested in building your own, check out the detailed instructions.

Similar DIY Security Projects:

• Laser Tripwire takes a Photo, Uploads it to Twitter
• DIY Rotating Bookshelves, Staircases and Trap Doors
• How to: Add a Secret Compartment to any Book

What do you do when you have an arduino, a camera, an ethernet shield and a doorbell? You make your own intelligent security system.

The system is actually pretty simple. When the doorbell rings an Arduino sends a request to a notification service called PushingBox which then grabs a picture from web camera located outside. Then PushingBox sends a notification to an iPhone (it looks like this can be modded slightly with PushingBox to include Android and Windows Phone as well) and an email with a picture attached.

Via:[Lifehacker]