Planning another Arduino build? If you’re just doing something simple like switching a relay or powering a LED, you might want to think about the Digispark. It’s a very small ATtiny-based Arduino compatible board developed and Kickstarted by [Erik].

The Digispark is based on the very popular Atmel ATtiny85, an 8 pin microcontroller that provides a quarter of the Flash storage and RAM as the ‘official Arduino’ ATMega328p. The lower storage space and RAM doesn’t mean the ’85 is a slouch, though; it can run Arduino code without a hitch, providing six pins for whatever small project you have in mind.

Right now, [Erik]‘s Kickstarter is offering three Digisparks for the price of a single Arduino. At that price, it’s cheap enough to leave in a project and not be repurposed after the build is over. [Erik] is also working on a few shields for the Digispark – only RGB LED shield for now, but hopefully he’ll get some more finished by the time the Kickstarter ends.

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.

As is common among some hackers, [Henry] re-purposed an ATX power supply unit to function as a bench power supply for testing circuits on a breadboard (much like this fancy example).

However, safety mechanisms on some modern PC PSUs do not automatically reset after over-current protection has kicked in, which soon became annoying for [Henry]. In order to make his power supply more hacker-friendly, he wired up and programmed an ATtiny85V, using some Arduino libraries, to do that for him. This simple project is a great example of using a hack to improve a pre-existing hack.

Hi geeks ;-)

I am thinking about to shrink some of my projects. That's the deal. I am planning to build a Attiny-Duino.

What would you think about it's usage? For myself I would use it in the Insect bot to reduce the weight, costs and power comsumption.