arduino

2946 Articles

RGB Disk Goes Interactive With Bluetooth; Shows Impressive Plastic Work

March 11, 2018 by 5 Comments

[smash_hand] had a clear goal: a big, featureless, white plastic disk with RGB LEDs concealed around its edge. So what is it? A big ornament that could glow any color or trippy mixture of colors one desires. It’s an object whose sole purpose is to be a frame for soft, glowing light patterns to admire. The disk can be controlled with a simple smartphone app that communicates over Bluetooth, allowing anyone (or in theory anything) to play with the display.

The disk is made from 1/4″ clear plastic, which [smash_hand] describes as plexiglass, but might be acrylic or polycarbonate. [smash_hands] describes some trial and error in the process of cutting the circle; it was saw-cut with some 3-in-1 oil as cutting fluid first, then the final shape cut with a bandsaw.

The saw left the edge very rough, so it was polished with glass polishing compound. This restores the optical properties required for the edge-lighting technique. The back of the disc was sanded then painted white, and the RGB LEDs spaced evenly around the edge, pointing inwards.

The physical build is almost always the difficult part in a project like this — achieving good diffusion of LEDs is a topic we talk about often. [smash_hands] did an impressive job and there are never any “hot spots” where an LED sticks out to your eye. With this taken care of, the electronics came together with much less effort. An Arduino with an HC-05 Bluetooth adapter took care of driving the LEDs and wireless communications, respectively. A wooden frame later, and the whole thing is ready to go.

[smash_hands] provides details like a wiring diagram as well as the smartphone app for anyone who is interested. There’s the Arduino program as well, but interestingly it’s only available in assembly or as a raw .hex file. A video of the disk in action is embedded below.

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High-Effort Streaming Remote For Low-Effort Bingeing

March 10, 2018 by 7 Comments

There’s no limit to the amount of work some people will put into avoiding work. For instance, why bother to get up from your YouTube-induced vegetative state to adjust the volume when you can design and build a remote to do it for you?

Loath to interrupt his PC streaming binge sessions, [miroslavus] decided to take matters into his own hands. When a commercially available wireless keyboard proved simultaneously overkill for the job and comically non-ergonomic, he decided to build a custom streaming remote. His recent microswitch encoder is prominently featured and provides scrolling control for volume and menu functions, and dedicated buttons are provided for play controls. The device reconfigures at the click of a switch to support Netflix, which like YouTube is controlled by sending keystrokes to the PC through a matching receiver. It’s a really thoughtful design, and we’re sure the effort [miroslavus] put into this will be well worth the dozens of calories it’ll save in the coming years.

A 3D-printed DIY remote is neat, but don’t forget that printing can also save a dog-chewed remote and win the Repairs You Can Print contest.

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You Don’t Need To Be Tony Stark To Afford This Hand Controller

March 9, 2018 by 4 Comments

Proving that duct tape really can do anything, [StudentBuilds] uses it to make a workable controller out of a glove. To be fair, there are a few more bits too, including paper coated with pencil graphite and tin foil, which forms a variable resistor you can read with an Arduino analog input. You can see the entire thing in the video below.

The source code is simple at this point — eventually, he plans to control a robotic hand with the controller, but that’s later. However, there’s no promised link to the code in the description, so you’ll have to freeze frame and type. However, it is pretty simple — just read the analog pin values to determine the specific values for each finger.

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Color-Coded Key Opens Doors, Opportunities

March 9, 2018 by 20 Comments

Of all the ways to open up a lock, there are some tried and true methods. Keys, combinations, RFIDs, picks, and explosives have all had their time and place, but now someone else wants to try something new. [Erik] has come up with a lock that opens when it is shown a pattern of colors.

The lock in question uses a set of color coded cards as the “keys”. When the cards are inserted in the lock, a TCS230 color sensor interprets the pattern on the cards and sends the information over to an Arduino Uno. From there, the Arduino can command the physical lock to open if the pattern is a match, although [Erik] is still waiting on the locking mechanism to arrive while he continues to prototype the device.

This is a fairly unique idea with a number of upsides. First, the code can’t be “stolen” from inside a wallet like RFID cards can. (Although if you can take a picture of the card all bets are off.) If you lose your key, you can simply print another one, and the device is able to handle multiple different keys and log the usage of each one. Additionally, no specialized equipment is needed to create the cards, unlike technologies that rely on magnetic strips. Of course, there’s always this classic way of opening doors if you’d rather go old school with your home locks.

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The Sensor Array That Grew Into A Robot Cat

March 6, 2018 by 32 Comments

Human brains evolved to pay extra attention to anything that resembles a face. (Scientific term: “facial pareidolia”) [Rongzhong Li] built a robot sensor array with multiple emitters and receivers augmenting a Raspberry Pi camera in the center. When he looked at his sensor array, he saw the face of a cat looking back at him. This started his years-long Petoi OpenCat project to build a feline-inspired body to go with the face.

While the name of the project signals [Rhongzhong]’s eventual intention, he has yet to release project details to the open-source community. But by reading his project page and scrutinizing his YouTube videos (a recent one is embedded below) we can decipher some details. Motion comes via hobby remote-control servos orchestrated by an Arduino. Higher-level functions such as awareness of environment and Alexa integration are handled by a Raspberry Pi 3.

The secret (for now) sauce are the mechanical parts that tie them all together. From impact-absorption spring integrated into the upper leg to how its wrists/ankles articulate. [Rongzhong] believes the current iteration is far too difficult to build and he wants to simplify construction before release. And while we don’t have much information on the software, the sensor array that started it all implies some level of sensor fusion capabilities.

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Automated Syrup System Is Sweet Sweet Madness

March 3, 2018 by 33 Comments

Here at Hackaday we are big fans of the TV show, “How It’s Made”. It’s not much of a stretch to assume that, as somebody who is currently reading this site, you’ve probably seen it yourself. While it’s always interesting to see the behind the scenes process to create everyday products, one of the most fascinating aspects of the show is seeing how hard it is to make things. Seriously, it’s enough to make you wonder how companies are turning a profit on some of these products when you see just how much technology and manual work is required to produce them.

That’s precisely the feeling we got when browsing through this absolutely incredible overview of how [HDC3] makes his maple syrup. If that’s not a sentence you ever thought you’d see on Hackaday, you aren’t alone. But this isn’t a rusty old pail hanging off of a tap, this is a high-tech automated system that’s capable of draining 100’s of gallons of sap from whole groves of trees. We’ll never look at a bottle of syrup in the store the same away again.

It all starts with hundreds of tiny taps that are drilled into the trees and connected to a network of flexible hoses. The plumbing arrangement is so complex that, in certain, areas high tension support wires are necessary to hold up the weight of the hoses and their sweet contents. The main hose leads to an Arduino-powered collection station which maintains a 100 kPa (29 inHg) vacuum throughout the entire system.

The sap is temporarily held in a 250 gallon container, but at this point it’s still just that: sap. It needs to be refined into something suitable for putting on your pancakes. The first step of that process utilizes a reverse osmosis filtration system to pull the water out of the sap and increase its sugar concentration. [HDC3] says the filtration system is built from eBay scores and parts from the home improvement store, and it certainly looks the part of something that would be under a kitchen sink. This system is able to increase the sugar concentration of the sap from around 2% as it comes out of the trees to 8%. But it’s still a far way off from being ready to use.

Interestingly enough, the last steps of the process are about as old-school as they come. The semi-concentrated sap is placed in a long low metal pan, and heated over a wood fire to drive off more of the water. This process continues until the sap is roughly 60% sugar, at which point it is filtered and moved into the house to finish boiling on the stove.

All told, the syrup is boiled for eight hours to bring its sugar content up to 66%. Even with the improvements [HDC3] has made to the system, he reveals that all this hard work only results in slightly more than a half-gallon of final syrup. Talk about dedication.

It probably comes as no surprise that this is the first time Hackaday has ever run a story about producing maple syrup. However we’ve seen a number of automated beer brewing systems that seem to have been tackled with similar zeal. There’s probably a conclusion to be drawn there about the average hacker’s diet, but that’s a bit outside our wheelhouse.

[via /r/DIY]

Definitive Dog Feeding With Arduino

February 27, 2018 by 3 Comments

Some dogs have no sense of self-preservation. Given the opportunity, they will eat until they’re sick. It’s up to us humans to both feed them and remember doing it so they aren’t accidentally overfed. In a busy household with young children, the tricky part is the remembering.

[Bryan]’s family feeds their dog Chloe once a day, in the mornings. She was a rescue who spent a few years scrounging for meals on the street, so some part of her is always interested in finding food, even if she just ate. Each morning, the flurry of activity throughout the house is compounded by Chloe’s repeated requests for food, so [Bryan] got his kids involved and built a simple circuit that lets everyone know—at a glance—whether Chloe was fed.

Chloe’s kibble is kept in a touch-top wastebasket that flips open at the press of a button. [Bryan]’s dog-fed detector uses a reed switch and an Arduino clone to detect when the lid is opened. When the reed switch goes, low, the Arduino lights up an LED. The light stays on for two hours and then shuts off automatically to get ready for the next day. You don’t have to beg for a demo video, because it’s waiting for you after the break.

Since Chloe devours a bowl of food in about two minutes flat, maybe the next project for [Bryan]’s family could teach her to slow down a bit.

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