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!

What do you do if your light switch is too far from your desk, and you’re in a rental property so you can’t put in extra wiring to install an electronic control for it? Get up and turn it on or off by hand? Of course not!

If you are [Guyfromhe], you solve this problem with a servo attached to a screw-on light switch faceplate, and you control it with a pair of Arduino/nRF24L01 combos. It’s a pretty simple arrangement, the wireless link simply takes the place of a serial cable that instructs the Arduino on the light switch to operate the servo that in turn moves the switch. The whole thing is triggered through his home automation system, which in turn responds to an Amazon Dash button on his desk. Yes, it’s complex. But turning on the light has been automated without intrusion into his landlord’s domain, and that’s all that matters.

On a more serious note, he’s put some Arduino code up on his write-up, as well as a YouTube video we’ve put below the break.

This is by no means the first such switch we’ve seen, after all we featured a nicer 3D printed servo light switch the other month, and one with a breadboarded Arduino in 2015. While we’re at it though, it would be nice to see a few designed for European switches too.

So [RobB] wanted to take out all the light switches in his house. His plan was to replace them with a system that could be operated from his smart phone. But his wife insisted that there still must be some way to control the lighting directly — we have to agree with her on that one. The solution was to develop a system that switches the lights via a touch sensor or by Bluetooth.

The touch part of the project is pretty easy. He coated the back of a blank outlet plate with tin foil and hooked it to a microcontroller with a couple of resistors. He’s using an ATtiny85, which can be programmed using Arduino sketches, so the software side is made easy by the CapSense Library. The chip also uses the software serial library to communicate with a Bluetooth module. You can see the result of both in the demo video after the break.

Of course you need to throw a relay in there to switch mains, and find a way to power the uC and Bluetooth module. [RobB] went with a tiny plug-in USB power converter and managed to fit everything in a single-gang switch.