Posts with «arduino nano» label

Automated Watering Machine Has What Plants Crave: Fertilizer

We’ve seen countless automated plant care systems over the years, but for some reason they almost never involve the secret sauce of gardening — fertilizer. But [xythobuz] knows what’s up. When they moved into their new flat by themselves, it was time to spread out and start growing some plants on the balcony. Before long, the garden was big enough to warrant an automated system for watering and fertilizing.

This clever DIY system is based around a 5L gravity-fed water tank with solenoid control and three [jugs] of liquid fertilizer that is added to the water via peristaltic pump. Don’t worry, the water tank has float switches, and [xythobuz] is there to switch it off manually every time so it doesn’t flood the flat.

On the UI side, an Arduino Nano clone is running the show, providing the LCD output and handling the keypad input. The machine itself is controlled with an ESP32 and a pair of four-channel relay boards that control the inlet valve, the four outlet valves, and the three peristaltic pumps that squirt out the fertilizer. The ESP also serves up a web interface that mimics the control panel and adds in the debug logs. These two boards communicate using I²C over DB-9, because that’s probably what [xythobuz] had lying around. Check out the demo video after the break, and then go check on your own plants. They miss you!

Don’t want to buy just any old peristaltic pumps? Maybe you could print your own.

Eyecam is Watching You in Between Blinks

We will be the first to admit that it’s often hard to be productive while working from home, especially if no one’s ever really looking over your shoulder. Well, here is one creepy way to feel as though someone is keeping an eye on you, if that’s what gets you to straighten up and fly right. The Eyecam research project by [Marc Teyssier] et. al. is a realistic, motorized eyeball that includes a camera and hangs out on top of your computer monitor. It aims to spark conversation about the sensors that are all around us already in various cold and clinical forms. It’s an open source project with a paper and a repo and a how-to video in the works.

The eyebrow-raising design pulls no punches in the uncanny department: the eye behaves as you’d expect (if you could have expected this) — it blinks, looks around, and can even waggle its brow. The eyeball, brow, and eyelids are actuated by a total of six servos that are controlled by an Arduino Nano.

Inside the eyeball is a Raspberry Pi camera connected to a Raspi Zero for the web cam portion of this intriguing horror show. Keep an eye out after the break for the Eyecam infomercial.

Creepy or fascinating, it succeeds in making people think about the vast amount of sensors around us now, and what the future of them could look like. Would mimicking eye contact be an improvement over the standard black and gray oblong eye? Perhaps a pair of eyes would be less unsettling, we’re not really sure. But we are left to wonder what’s next, a microphone that looks like an ear? Probably. Will it have hair sprouting from it? Perhaps.

Yeah, it’s true; two eyes are more on the mesmerizing side, but still creepy, especially when they follow you around the room and can shoot frickin’ laser beams.

Thanks for the tip, [Sven, greg, and Itay]!

Nixie Shot Timer Adds Useful Elegance to Espresso Machine

Once you’ve ground the beans and tamped the grounds just so, pulling the perfect shot of espresso comes down to timing. Ideally, the extraction should last 20-30 seconds, from the first dark drips to the tan and tiger-striped crema on top that gives the espresso a full aftertaste.

[Marco] has a beautiful espresso machine that was only missing one thing: an equally beautiful shot timer with a Nixie tube display. Instead of messing with the wiring, [Marco] took the non-invasive approach and is using a DIY coil to detect the magnetic field of the espresso machine’s pump and start a shot timer.

An LM358-based op-amp magnifies the current induced by the machine and feeds it to an Arduino Nano, which does FFT calculations. [Marco] found a high-voltage interface driver to switch 170 V to the Nixies instead of using two handfuls of transistors. Grab yourself a flat white and check it out after the break.

The last Nixies may have been mass-produced in the 1980s, but never fear — Dalibor Farny is out there keeping the dream alive and making new Nixies.

Negative Reinforcement: Drill Bits Edition

In theory, it’s fun to have a lot of toys tools around, but the sad reality is that it’s only as fun as the organization level applied. Take it from someone who finds organization itself thrilling: it really doesn’t matter how many bits and bobs you have, as long as there’s a place for everything and you put away your toys at the end of the day.

[Cranktown City] is always leaving drill bits lying around instead of putting them back in their bit set boxes. Since he responds well to yelling, he decided to build an intelligent drill bit storage system that berates him if he takes one out and doesn’t put it back within ten minutes.

But [Cranktown City] did much more than that. The system is housed in a really nice DIY stand that supports his new milling and drilling machine and has space to hold a certain type of ubiquitous red tool box beneath the drill bits drawer.

All the bits now sit in a 3D-printed index that fits the width of the drawer. [Cranktown City] tried to use daisy-chained pairs of screws as contacts behind each bit that could tell whether the bit was home or not, but too much resistance interfered with the signal. He ended up using a tiny limit switch behind each bit instead. If any bit is removed, the input signal from the index goes low, and this triggers the Arduino Nano to do two things: it lights up a strip of red LEDs behind the beautiful cut out letters on the drawer’s lip, and it starts counting upward. Every ten minutes that one or more bits are missing, the drawer complains and issues ad hominem attacks. Check out the demo and build video after the break, but not until you put your tools away. (Have you learned nothing?)

Okay, so how do you deal with thousands of jumbled drill bits? Calipers and a Python script oughta do it.

Motor-Driven Movement Modernizes POV Toy

Just as we are driven today to watch gifs that get better with every loop, people 100+ years ago entertained themselves with various persistence of vision toys that used the power of optical illusions to make still images come to life. [jollifactory] recently recreated one of the first POV devices — the phenakistoscope — into a toy for our times.

The original phenakistoscopes were simple, but the effect they achieved was utterly amazing. Essentially a picture disk with a handle, the user would hold the handle with one hand and spin the disk with the other while looking in a mirror through slits in the disk. Unlike the phenakistoscopes of yore that could only be viewed by one person at a time, this one allows for group watching.

Here’s how it works: an Arduino Nano spins a BLDC motor from an old CD-ROM drive, and two strips of strobing LEDs provide the shutter effect needed to make the pictures look like a moving image.The motor speed is both variable and reversible so the animations can run in both directions.

To make the disks themselves, [jollifactory] printed some original phenakistiscopic artwork and adhered each one to a CD that conveniently snaps onto the motor spindle. Not all of the artwork looks good with a big hole in the middle, so [jollifactory] created a reusable base disk with an anti-slip mat on top to spin those.

If you just want to watch the thing in action, check out the first video below that is all demonstration. There be strobing lights ahead, so consider yourself warned. The second and third videos show [jollifactory] soldering up the custom PCB and building the acrylic stand.

There are plenty of modern ways to build old-fashioned POV toys, from all-digital to all-printable.

A Tubular Fairy Tale You Control with Your Phone

At first glance, this might appear to be a Rube Goldberg machine made of toys. The truth isn’t far off — it’s a remote-control animatronic story machine driven by its spectators and their phones. [Niklas Roy] and a team of volunteers built it in just two weeks for Phaenomenale, a festival centered around art and digital culture that takes place every other year.

A view of the tubes without the toys.

A red ball travels through a network of clear acrylic tubes using 3D printed Venturi air movers, gravity, and toys to help it travel. Spectators can change the ball’s path with their phones via a local website with a big picture of the installation. The ball triggers animations along its path using break beam detection and weaves a different story each time depending on the toys it interacts with.

Here’s how it works: a Raspberry Pi 4 is responsible for releasing the ball at the beginning of the track and for controlling the track switches. The Pi also hosts a server for smartphones and the 25 Arduino Nanos that control the LEDs and servos of the animatronics. As a bonus animatronic, there’s a giant whiteboard that rotates and switches between displaying the kids’ drawings and the team’s plans and schematics. Take a brief but up-close tour after the break.

This awesome art project was a huge collaborative effort that involved the people of Wolfsburg, Germany — families in the community donated their used and abandoned toys, groups of elementary school kids were brought in to create stories for the toys, and several high school kids and other collaborators realized these drawings with animatronics.

Toys can teach valuable lessons, too. Take this body-positive sushi-snarfing Barbie for example, or this dollhouse of horrors designed to burn fire safety into children’s brains.

Gigantic Working Arduino Uses 1/4″ Cables

What is it about larger-than-life versions of things that makes them so awesome? We’re not sure exactly, but this giant working Arduino definitely has the ‘it’ factor, whatever that may be. It’s twelve times the size of a regular Uno and has a Nano embedded in the back of it. To give you an idea of the scale, the reset button is an arcade button.

The Arduino Giga’s PCB is made of 3/4″ plywood, and the giant components represent a week and a half of 3D printing. The lettering and pin numbers are all carved on a CNC and filled in with what appears to be caulk. They didn’t get carved out deeply enough the first time around, but [byte sized] came up with a clever way to perfectly re-register the plywood so it carved in exactly the same places.

Although we love everything about this build, our favorite part has to be the way that [byte sized] made the female headers work. Each one has a 1/4″ audio jack embedded inside of it (a task which required a special 3D printed tool), so patch cables are the new jumper cables. [byte sized] put it to the test with some addressable RGB LEDs on his Christmas tree, which you can see in the build video after the break.

You can buy one of those giant working 555 timer kits, but why not just make one yourself?

Mind-Controlled Beer Pong Gets Easier as You Drink

Wouldn’t it be nice if beer pong could somehow get easier the more you drink? You know, so you can drink more? [Ty Palowski] has made it so with automated, mind-controlled beer pong.

[Ty] started by making a beer pong table that moves the cups back and forth at both ends. An Arduino Nano controls a stepper that controls a slider, and the cups move with the slider through the magic of magnets. The mind control part came cheaper than you might think. Back in 2009, Mattel released a game called Mind Flex that involves an EEG headset and using brain waves to guide a foam ball on a stream of air through a little obstacle course. These headsets are available for about $12 on ebay, or at least they were before this post went up.

[Ty] cracked open the headset added an HC-06 Bluetooth module to talk to the Arduino. It’s using a program called Brainwave OSC to get the raw data from the headset and break it into levels of concentration and relaxation. The Arduino program monitors the attention levels, and when a certain threshold of focus is reached, it moves the cups back and forth at a predetermined speed ranging from 1 to an impossible-looking 10. Check out the two videos after the break. The first one covers the making of the the automatic beer pong part, and the second is where [Ty] adds mind control.

We’ve seen a different headset — the hacker-friendly NeuroSky Mindwave — pop up a few times. Here’s one that’s been hacked to induce lucid dreaming.

Via r/duino

Cornhole Boards Play Victory Songs

How do you instantly make any game better? By lighting it up and playing at night. We would normally say ‘drinking’, but we’re pretty sure that drinking is already a prerequisite for cornhole — that’s the game where you toss bean bags at holes in angled boards.

[Hardware Unknown] loves cornhole, and was gifted a set of portable, folding boards that light up around the ring for nighttime action. These turned out to be the perfect basis for reactive boards that light up and play sound whenever points are scored. Both boards have a vibration sensor to detect bags hitting the top, and an IR break-beam sensor pair across the hole. An Arduino Nano reads from the sensors and controls an amplifier and a DF Player for sound.

Players get a point and a song for landing a bag on top of the board, and three points and a different song for making it in the hole. We love the Easter egg — anyone who manages to trip both the vibration sensor and the break-beam detector at the same time will be treated to the sound of a flock of honking geese. Check out the build journey after the break.

No good at cornhole? This one doesn’t let you miss.

Bet You Didn’t Know Arduinos Are Psychic

Are you running out of ways to entertain yourself and your family? If you’ve read all the books and watched all the movies, it might be time to explore the psychic abilities of silicon. [Hari Wiguna] has just the trick to keep them guessing for a good long time.

This trick doesn’t take much, just a couple of Arduinos, some momentary buttons, a number pad, and a large helping of math. As you can see in the demo after the break, there is nothing connecting the two, not even 802.11(n). On the randomizer Arduino, [Hari] generates random numbers with the push of a button until the audience sees one they like. Then [Hari] locks in the number with the other button.

What happens next is key: the randomizer generates another random number, but uses it as a hint to set a sentinel digit. The randomizer Arduino subtracts the larger of the two digits in the number from nine and stores the result as the flag. When the next number comes up that has the flag digit in the correct place, the number after that will be the random number chosen at the beginning.

The psychic Arduino’s secret is that it knows the first guess it receives is special. It does the same sentinel digit math as the randomizer, so when the guesser enters the guess with the sentinel digit, it knows the next number entered is the winner. Clear as mud? Check out the second video below where [Hari] explains the trick, a new take on a magic classic.

Looking for a more exciting way to generate random numbers? Try using fish tanks, lava lamps, or muons from outer space.