When project inspiration strikes, we’d love to do some quick tests immediately to investigate feasibility. Sadly we’re usually far from our workbench and its collection of sensor modules. This is especially frustrating when the desired sensor is in the smartphone we’re holding, standing near whatever triggered the inspiration. We could download a compass app, or a bubble level app, or something similar to glimpse sensor activity. But if we’re going to download an app, consider Google’s Science Journal app.
It was designed to be an educational resource, turning a smartphone’s sensor array into a pocket laboratory instrument and notebook for students. Fortunately it will work just as well for makers experimenting with project ideas. The exact list of sensors will depend on the specific iOS/Android device, but we can select a sensor and see its output graphed in real-time. This graph can also be recorded into the journal for later analysis.
Science Journal was recently given a promotional push by the band OK Go, as part of their OK Go Sandbox project encouraging students to explore, experiment, and learn. This is right up the alley for OK Go, who has a track record of making music videos that score high on maker appeal. Fans would enjoy their videos explaining behind-the-scene details in the context of math, science, and music.
An interesting side note. Anyone who’s been to Hackaday Superconference or one of the monthly Hackaday LA meetups will likely recognized the venue used in many of the OK Go Sandbox videos. Many of them were filmed at the Supplyframe Design Lab in Pasadena. It’s also nice to see AnnMarie Thomas (Hackaday Prize Judge from 2016 and 2017) collaborated with OK Go for the Sandbox project.
While the Science Journal app has provisions for add-on external sensors, carrying them around would reduce its handy always-available appeal. Not that we’re against pairing smartphones with clever accessories to boost their sensing capabilities: we love them! From trying to turn a smartphone into a Tricorder, to an inexpensive microscope, to exploring serious medical diagnosis, our pocket computers can do it all.
[Xose Pérez] set out to make a sundial wristwatch by combining a magnetometer a small nylon bolt for the gnomon, but it doesn’t work like you’d think. Instead of using the magnetometer to point the sundial north, you angle the watch until the bolt’s shadow matches the white line on the PCB, and the ATmega328P computes the azimuth of the sun and determines the time thereby. To display the time he used one of those QDSP-6064 bubble displays, because sundials are retro.
His description of the project build includes a lot of fun anecdotes, like him attempting to solder the LCC connections of the HMC5883 magnetometer before giving up and making use of Seeedstudio’s PCBA service. He got 10 boards back with the ATmega and magnetometer populated while leaving the rest for [Xose] to fill in.
One fun detail of the project? You can’t tell what time it is without the sun, but you can’t read the bubble display in bright sunlight.
If you’re looking for more watch projects we’ve published, check out this wrist-controlled watch, the Chronio DIY watch, and this cool nixie-tube watch.
What will it take to make your house smarter than you? Judging from the price of smart appliances we see in the home centers these days, it’ll take buckets of cash. But what if you could make your home smarter — or at least more observant — with a few cheap, general purpose “supersensors” that watch your every move?
Sounds creepy, right? That’s what [Gierad Laput] and his team at the Carnegie Mellon Human-Computer Interaction Institute thought when they designed their broadband “synthetic sensor,” and it’s why they purposely omitted a camera from their design. But just about every other sensor under the sun is on the tiny board: an IR array, visible light sensors, a magnetometer, temperature, humidity, and pressure sensors, a microphone, PIR, and even an EMI detector. Of course there’s also a WiFi module, but it appears that it’s only for connectivity and not used for sensing, although it clearly could be. All the raw data is synthesized into a total picture of the goings on in within the platform’s range using a combination of machine learning and user training.
The video after the break shows the sensor detecting typical household events from a central location. It’s a powerful idea and we look forward to seeing how it moves from prototype to product. And if the astute reader recognizes [Gierad]’s name, it might be from his past appearance on these pages for 3D-printed hair.
Continue reading “Sense All the Things with a Synthetic Sensor”
With interest and accessibility to both wearable tech and virtual reality approaching an all-time high, three students from Cornell University — [Daryl Sew, Emma Wang, and Zachary Zimmerman] — seek to turn your body into the perfect controller.
That is the end goal, at least. Their prototype consists of three Kionix tri-axis accelerometer, gyroscope and magnetometer sensors (at the hand, elbow, and shoulder) to trace the arm’s movement. Relying on a PC to do most of the computational heavy lifting, a PIC32 in a t-shirt canister — hey, it’s a prototype! — receives data from the three joint positions, transmitting them to said PC via serial, which renders a useable 3D model in a virtual environment. After a brief calibration, the setup tracks the arm movement with only a little drift in readings over a few minutes.
Continue reading “Your Arm Is The Ideal Controller”
The “Navigation Thing“ was designed and built by [Jan Mrázek] as part of a night game activity for high school students during week-long seminar. A night-time path through a forest had stations with simple tasks, and the Navigation Thing used GPS, digital compass, a beeper, and a ring of RGB LEDs to provide a bit of “Wow factor” while guiding a group of students from one station to the next. The devices had a clear design direction:
“I wanted to build a device which a participant would find, insert batteries, and follow the beeping to find the next stop. Imagine the strong feeling of straying in the middle of the night in an unknown terrain far away from civilization trusting only a beeping thing you found. That was the feeling I wanted to achieve.”
The Navigation Things (there are six in total) guide users to fixed waypoints with GPS, a digital compass, and a ring of WS2812 LEDs — but the primary means of feedback to the user is a beeping that gets faster as you approach the destination. [Jan] had only four days to make all six units, which was doable. But as most of us know, delivering on a tight deadline is often less about doing the work you know about, and more about effectively handling the unexpected obstacles that inevitably pop up in the process.
Continue reading “Navigation Thing: Four Days, Three Problems, and Fake Piezos”
Resistors are one of the fundamental components used in electronic circuits. They do one thing: resist the flow of electrical current. There is more than one way to skin a cat, and there is more than one way for a resistor to work. In previous articles I talked about fixed value resistors as well as variable resistors.
There is one other major group of variable resistors which I didn’t get into: resistors which change value without human intervention. These change by environmental means: temperature, voltage, light, magnetic fields and physical strain. They’re commonly used for automation and without them our lives would be very different.
Continue reading “Automatic Resistance: Resistors Controlled by the Environment”
It’s no secret that hackers like to measure things. Good numbers lead to good decisions, like when to kick your wastrel teenager out of a luxuriously lengthy shower. Hence the creation of this wireless Arduino-based water meter interface.
We’ll stipulate that “wireless” is a bit of a stretch. Creator [David Schneider] chose to split the system into two parts – a magnetometer and an Arduino to sense impulses from the water company meter, and a Raspberry Pi to serve the web interface. The water meter is at the street rather than in his house, so the sensor is wired to the Pi with some telephone cable. But from there the system is wireless.
[David] goes into some good detail on the sensing problem he faced, which relies on detecting the varying magnetic field due to the spinny-bits inside the flowmeter and cleaning up the signal with the Arduino; he also addresses aliasing errors that occur when flow rate approaches the sampling rate of the magnetometer.
We like the fact that there’s a lot of potential to leverage this technique to monitor other processes with rotating magnetic fields. And like this optically coupled gas-meter monitor, it’s not invasive of the utility’s equipment either, which is a plus.