If you have a loved one with Alzheimer’s, you know how difficult it can be to hold a conversation with them that doesn’t constantly go in circles. A good way to keep them focused is to use conversation pieces like pictures and familiar objects from their past. Something particularly poignant might uncork a flood of memories.
Alzheimer’s is a pretty tough test for intuitive interfaces. Because of this, [Annelle] and [Mike] designed around the constraints of buttons and switches. Instead, the book uses light-dependent resistors mounted inside the back cover, and an increasing number of holes in each page. These photo cells are all wired to an Adafruit sound board, which figures out the active page based on the input voltage and plays the corresponding song.
Tilt switches inside the 3D-printed enclosure negate the need for a power button. The book is turned off when lying flat on a table, but it’s ready to rock in any other position. Turn past the break for an overview video and another that covers the page detection scheme.
If you haven’t heard of it, the Mooshimeter is a two channel multimeter that uses your smartphone as a display over Bluetooth 4.0. The ability to simultaneously monitor voltage and current is rather unique, and the fact that you aren’t physically tethered to the thing makes it ideal for use in hard to reach or even dangerous locations. The promotional material for the Mooshimeter shows users doing things like leaving the device inside the engine compartment of a car while they drive around and take readings about the vehicle’s electrical system.
All that sounds well and good, but at the end of the day, the Mooshimeter is probably not going to be your primary multimeter. It’s going to stay on a shelf until a task befitting its unique abilities comes along. Unfortunately, as [nop head] found, that can be a problem. Like many modern devices, the Mooshimeter doesn’t actually turn off. It just sits there draining its battery until you’re ready to use it. Which of course means that when you’re finally ready to pull the thing out and put it to use, you get a low battery warning and need to put new AAs in it. First World problems.
The fix for this thoroughly modern problem is delightfully old school: a mercury tilt switch.
Using a small spacer made of Kapton tape, [nop head] was able to isolate the battery contacts from the PCB itself. He then soldered the mercury switch in place between them, making sure to position the bulb vertically. When the Mooshimeter is right side up, the mercury flows down and bridges the contacts; but when the device is inverted the contact is broken and the batteries stop draining. He still has to remember to put the Mooshimeter face down when he’s done with it, but it’s better than dealing with constant dead batteries.
Basic geocaching consists of following GPS coordinates to a location, then finding a container which is concealed somewhere nearby. Like any activity, people tend to add their own twists to keep things interesting. [Jangeox] recently posted a video of the OLED Snail 2.0 to show off his most recent work. (This is a refinement of an earlier version, which he describes in a blog post.)
[Jangeox] spices up geocaching by creating electronic waypoints, and the OLED Snail is one of these. Instead of GPS coordinates sending someone directly to a goal, a person instead finds a waypoint that reveals another set of coordinates and these waypoints are followed like a trail of breadcrumbs.
A typical waypoint is an ATTINY85 microcontroller programmed to display an animated message on the OLED, and the message reveals the coordinates to the next waypoint. The waypoint is always cleverly hidden, and in the case of the OLED Snail 2.0 the enclosure is the shell of a large snail containing the electronics encased in resin. This means that the devices have a finite lifespan — the battery sealed inside is all the power the device gets. Fortunately, with the help of a tilt switch the electronics can remain dormant until someone picks it up to start the show. Other waypoints have included a fake plant, and the fake bolt shown here. Video of the OLED Snail 2.0 is embedded below.
If you’re trying to detect the orientation of an object, sometimes you really don’t need a 6DOF gyro and accelerometer. Hell, if you only need to detect if an object is tilted, you can get a simple “ball in a tube” tilt sensor for pennies. [tamberg] liked this idea, but he required a tilt sensor that works in the X, Y, and Z axes. Expanding on the ‘ball in a tube’ construction of simple tilt sensors, he designed a laser cut 3D tilt sensor that does all the work of of a $30 IMU.
The basic design of this tilt sensor is pretty simple – just an octahedron with four nails serving as switch contacts at each vertex. An aluminum ball knocks around inside this contraption, closing the nail head switches depending on what orientation it’s in. Simple, and the three dimensional version of a ball in tube tilt sensor.
To get the tilt data to the outside world, [tamberg] is using an Adafruit Bluetooth module, with two of the nails in each corner connected to a pin. With just a little bit of code, this 3D tilt sensor becomes a six-way switch to control an RGB LED. Video of that below.
We all need an excuse to play Half-Life 2 sometimes. [Jeri Ellsworth] put together a My First Crowbar controller to throw a few headcrabs across the room. It’s pretty much Half-Life 2 for the Wii.
The build is very simple – just a tilt switch hot glued to the underside of a childs-size crowbar. Two leads go from the tilt switch to the contacts on a (PS3?) controller. All you need to do to attack is swing the crowbar wildly.
[Jeri] has us wondering what other awesome game controllers could be made. Of course we’ve been wanting a real-life Gravity Gun or Portal Gun for years now, but right now we’re thinking about a real Katamari. We might need more hot glue.
As far as building our own, we’re thinking about using one of the Cheap DIY tilt switches we saw the other day. It’s a simple build, and sure looks like a lot of fun.
[fjordcarver] was looking for some mercury-free tilt switches that wouldn’t break the bank and that were easy to build. He also wanted something cheap, so instead of buying some tilt switches he devised his own that fit all of the criteria he set out. Now, these switches are not your typical fare, and they’re not small either. They are however, cheap, effective, and easy to manipulate/repair.
He picked up a package of metallic craft beads at the store and emptied out two bottles, saving one set of beads that happened to be conductive, i.e. not coated with paint or coloring. The beads were split between two jars, which were then sealed with corks that had a pair of straightened paperclips inserted through them. The bottles were oriented facing away from one another, then attached together with a piece of house wire. One of the leads from each jar was attached to this common wire, while the others were extended with hook up wire for use in the circuit he was building. Pictures definitely explain the mechanism far better than words can, so be sure to check out his tutorial to get a better look at them.
While they might look a bit rough, he says they work great, so give them a try if you have the need.
If you’re gaming on the road, or just don’t have a die with the right number of sides on hand, an electronic polyhedral die will be quite handy. [Marcus] built this using a printed circuit board of his own design, and we think an electronically simple project like this is a great way to get your feet wet with PCB fab house techniques. He suggests Seeed Studios’ service, or the DorkBotPDX group PCB order. But this would not be a hard project to build on perfboard as well.
The concept is simple. A two-digit 7-segment display shows the value of the top face of your die. when it’s time to roll, just pick up the box and tip it over. A tilt switch senses this action and rolls the die by displaying the next pseudo-random number. The single button, seen here with a pyramid die glued to it, lets you select between die with different number of sides; from 2 (like a coin flip) all the way up to 100.