Pips Help Everyone Around the House

Sometimes you start a project with every intention of using it in a specific way, or maybe your plan is to have a very well-defined set of features. Often, though, our projects go in a completely different direction than we might have intended. That seems to be the case with [Dave] and his Pips. These tiny devices were originally intended to be used by people with disabilities, but it turns out that they’re a perfect platform for this “Internet of Things” thing that we’ve been hearing so much about.

Built around the Bright Blue Bean microcontroller platform to take advantage of its low energy requirements, the Pips were originally intended to be placed around the house where they would light up to remind the user to perform some task. Once the button was pushed, the next Pip in the sequence would activate. While they are quite useful for people with cognitive or sensory impairments, they can also be used in a similar way to the Amazon Dash button or any other simple internet-enabled device. Especially when used in conjunction with a home automation setup, this device could be used in novel ways, such as automating your morning routine without having to add a weight sensor to your bed.

We are also pleased to see that all of the project files are available on GitHub for anyone looking to try this out. Its interesting when something that was originally intended to help out anyone with a disability finds a use somewhere else that it might not have originally been intended for. After all, though, the principle of using things in novel ways is kind of the entire basis of this community.

Two dice, one 8-pin uC

[Mike Shegedin] makes full use of an 8-pin microcontroller with this ATtiny13-based dice project. With a maximum of six I/O pins (that includes using the reset pin as I/O) he needed a couple of tricks in order to drive 14 LEDs and use a momentary push button for user input. We’re certainly familiar with the concepts here, but it still took quite a while to figure out what is going on with the schematic that [Mike] posted.

You’ve probably already guessed that he’s using Charlieplexing to drive more LEDs than he has pins. But when we started looking at the layout we thought he had drawn the schematic wrong, because there are six pairs of LEDs where the two diodes in each pair a not reverse biased, but hooked up in parallel. That, plus the fact that his battery is hooked up backwards. After several minutes of study the light bulb finally clicked on. Dice add pips (the dots on each side of a die) in pairs with the exception of the center pip. That means that you only need to control four total lines for each die (three pairs plus the center pip). There’s two ways to handle this, you could use four rows and two columns with traditional multiplexing, or you can reverse bias the two sets of LEDs for each die and use Charlieplexing. The former is a bit easier to program, the latter saves you one I/O pin and meant that [Mike] didn’t need to use the reset pin as I/O.

This is a clever addition to the collection of dice projects we’ve seen like the battery-less die, and the ATtiny2313 powered dice.