It is likely that many of us will at some time have experimented with motion detectors. Our Arduinos, Raspberry Pis, Beaglebones or whatever will have been hooked up to ultrasonic or PIR boards which will have been queried for their view of what is in front of them.

[Connornishijima] has stumbled on a different way to detect motion with an Arduino, he’s polling an ADC pin with a simple length of twisted pair hooked up to it and earth, and reliably generating readings indicating when he (or his cat) is in its vicinity. He’s calling the effect “Capacitive turbulence”, and he’s open to suggestions as to its mechanism. He can only make it work on the Arduino, other boards with ADCs don’t cut it.

Frequent Hackaday featuree [Mitxela] may have also discovered something similar, and we’ve hesitated to write about it because we didn’t understand it, but now it’s becoming unavoidable.

It’s always dangerous in these situations to confidently state your opinion as “It must be…” without experimental investigation of your own. Those of us who initially scoffed at the idea of the Raspberry Pi 2 being light sensitive and later had to eat their words have particular cause to remember this. But this is an interesting effect that bears understanding. We would guess that the Arduino’s fairly high input impedance might make it sensitive to mains hum, if you did the same thing to an audio amplifier with a phono input you might well hear significant hum in the speaker as your hand approached the wire. It would be interesting to try the experiment at an off-grid cabin in the woods, in the absence of mains hum.

If you’d like to give his experiment a try, he’s posted his sketch on Pastebin. And he’s put up the video below the break demonstrating the effect in action, complete with cats.

We like to see people pushing the boundaries of what is possible with their microcontroller I/O lines, it furthers our collective knowledge as a community. We’ve seen people making  TV transmitters from ESP8266s, and not so long ago a Raspberry Pi ADC port as further examples. Please, keep them coming!

A few years ago, you could buy an IRIS 9000 Bluetooth speaker. Its claim to fame was that it looked like the “eye” from the HAL 9000 computer on 2001: A Space Oddessy. There’s something seductive about the idea of having a HAL eye answer your queries to Google Now or Siri. The problem is, it still sounds like Google or Siri, not like HAL.

[Badjer1] had the same problem so he decided to build his own eye. His goal wasn’t to interface with his smartphone’s virtual assistant, though. He settled on making it just be an extension cord with USB ports. As you can see in the video below, the build has HAL-style memory units, a key, and can speak phrases from the movie (well, 28 of them, at least). The key is like the one Dave used to deactivate HAL in the movie.

Inside the MDF enclosure is an Arduino and a wave shield that handles the audio playback. The memory cards are acrylic and the key is machined brass. The result is a good looking project.

If you really want to be HAL, you can build a costume. We’ve seen a similar build with a Raspberry Pi.

Flying a drone usually leads to–sooner or later–crashing a drone. If you are lucky, you’ll see where it crashes and it won’t be out of reach. If you aren’t lucky, you’ll know where it is, but it will be too high to easily reach. The worst case is when it just falls out of the sky and you aren’t entirely sure where. [Just4funmedia] faced this problem and decided to use some piezo buzzers and an Arduino to solve it.

Yeah, yeah, we know. You don’t really need an Arduino to do this, although it does make it easy to add some flexibility. You can pick two tones that are easy to hear and turn on the buzzers with a spare channel or sense a loss of signal or power.

The device has its own battery so it will work even if the drone’s power depletes. Apparently, the 9V battery will run the whole thing for over 20 hours. Pulsing the audio would probably push that number even higher. Of course, the downside is the drone has to carry the extra weight, but if you recover an otherwise lost drone, that might be a small price to pay.

This might be more practical than a calculus-based approach. Maybe like a tightrope walker, you’d rather use a net.

The Raspberry Pi was made to be inexpensive with an eye toward putting them into schools. But what about programs targeted at teaching embedded programming? There are plenty of fiscally-starved schools all over the world, and it isn’t uncommon for teachers to buy supplies out of their own pockets. What could you do with a board that cost just one dollar?

That’s the idea behind the team promoting the “One Dollar Board” (we don’t know why they didn’t call it a buck board). The idea is to produce a Creative Commons design for a simple microcontroller board that only costs a dollar. You can see a video about the project, below.

Despite being licensed under Creative Commons, there isn’t much detail available that we could find. It appears the board uses an 8 pin Atmel CPU (and the FAQ indicates that the board will use the Arduino IDE). We’re guessing that it’s essentially a Digispark / Adafruit Trinket / ATtiny85 with V-USB installed.

The crowdfunding campaign page lists the following details:

• CPU: 8-bit
• GPIO (input and output ports): 6
• USB Interface: Yes
• Memory: Flash 8 kBytes (expandable to 256 kBytes)
• Spaces for expansions: WiFi ESP8266, Memory 24C256, H bridge L293
• Voltage: 5V
• Indicator LEDs: 2
• Reset Button: Yes
• Fitting Spaces: 4 (compatible with Arduíno UNO or similar)
• Quick Guide: The English board comes with a printed guide in other languages.

If it is an ATTtiny85-based design, two of those “GPIO” pins will be eaten up by the USB programmer, and maybe two more by the indicator LEDs. And some of that 8 kB of flash is consumed by the bootloader. In short, it’s not going to be able to do everything all at once. Still, it could be just the thing for getting your feet wet.

But the real story is the price. The dollar price tag doesn’t include shipping or taxes, of course, but even getting the price down that low is impressive. Time will tell if the market has an appetite for a dollar board. If we had to guess, the real value will be in ready-made course material.

There are plenty of educational boards out there, but few (if any) cost a buck.

A large installed base of powered speakers from a defunct manufacturer and a dwindling supply of working remote controls. Sounds like nightmare fuel for an AV professional – unless you take matters into your own hands and replace the IR remotes with an Arduino and custom software.

From the sound of it, [Steve]’s crew was working on AV gear for a corporate conference room – powered speakers and an LCD projector. It was the speakers that were giving them trouble, or rather the easily broken or lost remotes. Before the last one gave up the ghost, [Steve] captured the IR codes for each button using an Arduino and the IRRemote library. With codes in hand, it was pretty straightforward to get the Nano to send them with an IR LED. But what makes this project unique is that the custom GUI that controls the Arduino was written in the language that everyone loves to hate, Visual Basic. It’s a dirty little secret that lots of corporate shops still depend on VB, and it’s good to see a little love for the much-maligned language for a change. Plus it got the job done.

Want to dive deeper into IR? Maybe this primer on cloning IR remotes with an Arduino will help. And for another project where VB shines, check out this voice controlled RGB LED lamp.

Wafer level chips are cheap and very tiny, but as [Kevin Darrah] shows, vulnerable to bright light without the protective plastic casings standard on other chip packages.

We covered a similar phenomenon when the Raspberry Pi 2 came out. A user was taking photos of his Pi to document a project. Whenever his camera flash went off, it would reset the board.

[Kevin] got a new Arduino 101 board into his lab. The board has a processor from Intel, an accelerometer, and Bluetooth Low Energy out of the box while staying within the same relative price bracket as the Atmel versions. He was admiring the board, when he noticed that one of the components glittered under the light. Curious, he pulled open the schematic for the board, and found that it was the chip that switched power between the barrel jack and the USB. Not only that, it was a wafer level package.

So, he got out his camera and a laser. Sure enough, both would cause the power to drop off for as long as the package was exposed to the strong light. The Raspberry Pi foundation later wrote about this phenomenon in more detail. They say it won’t affect normal use, but if you’re going to expose your device to high energy light, simply put it inside a case or cover the chip with tape, Sugru, or a non-conductive paint to shield it.

The internet of things is this strange marketing buzzword that seems to escape from the aether and infect our toasters and refrigerators. Now even a hamster is not safe.

[Mifulapirus]’s hamster, Ham, was living a pleasant hamster life. Then his owner heard about another hamster named Sushi, whose running wheel stats were broadcasted to the internet. Not to be left behind, Ham’s wheel was soon upgraded. Now Ham is burdened by the same social pressures our exercise apps try to encourage us to use. No, we are most certainly not going to tell our friends about two fourteen minute miles with a twenty minute coffee break in the middle, MapMyRun, we are not.

The feat of techno enslavement for the little hamster was accomplished with a custom board, an esp8266, and an arduino as described in the instructable. The arduino can be left out of the project now that the libraries have been ported to the esp8266. A hall effect sensor detects when the 3D printed hamster wheel is spinning.

If you’d like to check in on Ham, the little guy is alive and well, and the twitter is here. It looks like it’s been upgraded since the original article was posted. Now it shows when Ham is awake and running around the cage doing hamster errands.

[Paul] participated in a hackathon at work and created a hack to help solve what was ultimately a people problem. A soda fridge at work wasn’t getting refilled when empty. Instead of trying to make people less lazy, [Paul] went with making the fridge more needy.

The first thing [Paul] did was make a soda fridge refill sensor from a scale. As the fridge got emptier, it got lighter. The scale senses that and can decide it’s time for a refill. The only part missing was how to read the output from the scale. To do that, he took an unusual approach.

The soda fridge sits on an analog scale with a dial. [Paul] saw there was no need to measure the exact weight of the fridge, only to detect a refill threshold. He came up with a simple hack: colored paper attached to the scale’s dial and an Arduino with an OSEPP COLOR‑01 color sensor pointed at the paper. The dial moves in response to the fridge’s changing weight, and the color sensor reads the color of the paper as it moves under the sensor. With a little bit of trial-and-error calibration and some barely modified sample code for the sensor, it was possible to reliably detect when the fridge required refilling. With the sensor done, it was time to use it to solve the lazy people problem.

In a way, the root problem wasn’t that people couldn’t be bothered to check if the fridge needed a refill – it was that the right people weren’t finding out at the right times. This resulted in spotty refilling as well as soda not being ordered when needed. This hack means that the fridge can now actively announce its state, which now allows things like notifying people via email that it is their turn to refill and re-order. It turns out that a fridge that can tell people what it needs has a much better chance of being serviced, compared to a one that has to wait for people to check up on it.

We’ve seen people interface directly to the load sensors in weight scales before, but this hack took a completely different approach.

Thanks to [Paul] for sharing.

If you are a regular Hackaday reader, you’ve probably seen plenty of ESP8266 projects. After all, the inexpensive device is a workhorse for putting a project on WiFi, and it works well. There is a processor onboard, but, most often, the onboard CPU runs a stock firmware that exposes an AT command set or Lua or even BASIC. That means most projects have a separate CPU and that CPU is often–surprise–an Arduino.

It isn’t a big leap of logic to imagine an Arduino with an integrated WiFi subsystem. That’s the idea behind the MKR1000. But the real question you have to ask is: is it better to use an integrated component or just put an Arduino and ESP8266 together?

[Andreas Spiess] not only asked the question, but he answered it in a YouTube video (see below). He examines several factors on the MKR1000, the Arduino Due and Uno, and several other common boards. The examination covers performance, features, and power consumption.

We’ve covered a slew of ESP8266 projects. We’ve also seen at least two MKR1000 projects, one for an automotive project and the other controls a shower.

[Mr_GreenCoat] is studying engineering. His thermodynamics teacher agreed with the stance that engineering is best learned through experimentation, and tasked [Mr_GreenCoat]’s group with the construction of a vacuum chamber to prove that the boiling point of a liquid goes down with the pressure it is exposed to.

His group used black PVC pipe to construct their chamber. They used an air compressor to generate the vacuum. The lid is a sheet of lexan with a silicone disk. We’ve covered these sorts of designs before. Since a vacuum chamber is at max going to suffer 14.9 ish psi distributed load on the outside there’s no real worry of their design going too horribly wrong.

The interesting part of the build is the hardware and software built to boil the water and log the temperatures and pressures. Science isn’t done until something is written down after all. They have a power resistor and a temperature probe inside of the chamber. The temperature over time is logged using an Arduino and a bit of processing code.

In the end their experiment matched what they had been learning in class. The current laws of thermodynamics are still in effect — all is right in the universe — and these poor students can probably save some money and get along with an old edition of the textbook. Video after the break.