The Arudino is a powerful platform for interfacing with the real world, but it isn’t without limits. One of those hard limits, even for the Arduino MEGA, is a finite number of pins that the microcontroller can use to interface with the real world. If you’re looking to extend the platform’s reach in one of your own projects, though, there are a couple of options available. This project from [Bill] shows us one of those options by using the ATtiny85 to offload some of an Arduino’s tasks using I2C.

I2C has been around since the early 80s as a way for microcontrollers to communicate with each other using a minimum of hardware. All that is needed is to connect the I2C pins of the microcontrollers and provide each with power. This project uses an Arduino as the controller and an arbitrary number of smaller ATtiny85 microcontrollers as targets. Communicating with the smaller device allows the Arduino to focus on more processor-intensive tasks while giving the simpler tasks to the ATtiny. It also greatly simplifies wiring for projects that may be distributed across a distance. [Bill] also standardizes the build with a custom dev board for the ATtiny that can also double as a shield for the Arduino, allowing him to easily expand and modify his projects without too much extra soldering.

Using I2C might not be the most novel of innovations, but making it easy to use is certainly a valuable tool to add to the toolbox when limited on GPIO or by other physical constraints. To that end, [Bill] also includes code for an example project that simplifies the setup of one of these devices on the software end as well. If you’re looking for some examples for what to do with I2C, take a look at this thermometer that communicates with I2C or this project which uses multiple sensors daisy-chained together.

It’s a little known secret that when the Hackaday writers gather in their secret underground bunker to work on our plans for world domination, we often take breaks to play our version of the corporate “Buzzword Bingo”, where paradigms are leveraged and meetings circle back to loop in offline stakeholders, or something like that. Our version, however, is “Comment Line Bingo”, and right in the middle of the card is the seemingly most common comment of all: “You should have used a 555,” or variations thereof.

So it was with vicious glee that we came across the Trollduino V1.0 by the deliciously named [Mild Lee Interested]. It’s the hardware answer to the common complaint, which we’ll grant is often justified. The beautiful part of this is that Trollduino occupies the same footprint as an Arduino Uno and is even pin-compatible with the microcontroller board, or at least sort of. The familiar line of components and connectors sprout from the left edge of the board, and headers for shields line the top and bottom edges too. “Sketches” are implemented in hardware, with jumpers and resistors and capacitors of various values plugged in to achieve all the marvelous configurations the indispensable timer chip can be used for. And extra points for the deliberately provocative use of Comic Sans in the silkscreen.

Hats off to [Lee] for a thoroughly satisfying troll, and a nice look at what the 555 chip can really do. If you want a more serious look at the 555, check out this 555 modeled on a breadboard, or dive into the story of the chip’s development.

In case you haven’t noticed, one of the more popular themes for new dev boards is Bluetooth. Slap a Bluetooth 4.0 module on a board, and you really have something: just about every phone out there has it, and the Low Energy label is great for battery-powered Internets of Things.

Most of these boards fall a little short. It’s one thing to throw a Bluetooth module on a board, but building the software to interact with this board is another matter entirely. Revealing Hour Creations is bucking that trend with their Tah board. Basically, it’s your standard Arduino compatible board with a btle module. What they’ve done is add the software for iOS and Android that makes building stuff easy.

Putting Bluetooth on a single board is one thing, but how about putting Bluetooth on everything. SAM Labs showed off their system of things at Maker Faire with LEDs, buttons, fans, motors, sensors, and just about every electrical component you can imagine.

All of these little boards come with a Bluetooth module and a battery. The software for the system is a graphical interface that allows you to draw virtual wires between everything. Connect a button to a LED in the software, and the LED will light up when the button is pressed. Move your mouse around the computer, and the button will turn on a motor when it’s pressed.

There are a few APIs that also come packaged into the programming environment – at the booth, you could open a fridge (filled with cool drinks that didn’t cost five dollars, a surprise for the faire) and it would post a tweet.