Suspense Courtesy Of Arduino, Mess Of Wires

November 6, 2018 by Zoe Skyforest 8 Comments

The ticking clock on the bomb is a Hollywood trope that simply refuses to die. Adding to the stress levels of the bomb squad and creating great suspense for the watcher, it’s always interesting to wonder why the average bomb maker is so courteous as to supply this information to law enforcement. Regardless, if you’d like to build a dramatic prop and are mature enough to do so responsibly, [Giorgio] has the guide you need.

The build is a straightforward one, relying on an Arduino to run the show. This is hooked up to a classic 7-segment LED display, upon which the countdown is displayed. For extra flair, an MP3 player is fitted to play the Mission Impossible theme. It all adds to the tension as you wipe the sweat from your brow, trying to decide if you’re cutting the right wire.

It’s a build that would be an excellent prop for a film production or a fun game at a holiday party. However, it’s also a build that could easily be mistaken for the real thing by those less technically inclined. Even the most innocuous homebrew projects have caused problems for innocent hackers in the past. Fake bombs can be incredibly dangerous, just like the real thing, so it’s important to be careful.

We’ve seen other takes on this kind of build before, too. As always, build responsibly.

The Nitty-Gritty Of Making A Brass Clock

July 29, 2018 by Jenny List 23 Comments

Among all the timepieces that we feature here at Hackaday, surprisingly we bring you relatively few clocks. That might seem an incomprehensible statement given the plethora of, well, clocks, that appear here, but it’s one that hinges upon the type of clock. Electronic clocks of extreme skill, complexity, and beauty, yes, but traditional mechanical clocks? Not so many.

So [Thonemeister]’s wall-mounted brass alarm clock was a welcome sight on our tips line, and his write-up is a fascinating exposition of the path taken by a novice clockmaker on their first build. He starts by describing his workshop, then steps methodically through each of the constituent parts of the clock.

We see the frame, escapement mechanism, gears, and movement taking shape, and we learn something about clockmaker’s tools from the pitfalls he encountered. He was a complete lathe novice at the start of this build, and it’s fun to follow along with his learning curve. As we see thed finished clock taking shape, we even get to see the little touches like forming the hooks for the weights. He bought the bell for the clock off-the-shelf, not wishing to expend the considerable piece of brass stock it would have taken to machine it himself. But for the most part, this is an engaging scratch build you won’t want to miss.

Many of us will never make a traditional clock. But that need not stop us finding the work that goes into one an extremely fascinating read. We have more for you if this has whetted your appetite: you’ll be interested in the escapement mechanism, and if brass is a bit much, how about wood?

Ask Hackaday: Is Your Clock Tied To Mains Frequency?

March 29, 2018 by Mike Szczys 162 Comments

Earlier in March we heard about a quirk of the interconnected continental European electricity grid which caused clocks to lose about six minutes so far this year. This was due to a slight dip in the mains frequency. That dip didn’t put anything out of commission, but clocks that are designed to accumulate the total zero-crossings of the power grid frequency of 50 Hz don’t keep accurate time when that frequency is, say 49.985 Hz for an extended period of time.

An interesting set of conversations popped up from that topic. There were several claims that modern alarm clocks, and most devices connected to mains, no longer get their clock timing from mains frequency. I’ve looked into this a bit which I’ll go into below. But what we really want to know is: are your alarm clocks and other devices keeping time with the grid or with something else?

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Wake Up To Fresh Coffee!

May 21, 2017 by Jenny List 18 Comments

Be careful what you say when you are shown a commercial product that you think you could make yourself, you might find yourself having to make good on your promise.

When he was shown a crowdfunded alarm clock coffee maker, [Fabien-Chouteau] said “just give me an espresso machine and I can do the same”. A Nespresso capsule coffee machine duly appeared on his bench, so it was time to make good on the promise.

The operation of a Nespresso machine is simple enough, there is a big lever on the front that opens the capsule slot and allows a spent capsule to drop into a hopper. Drop in a new capsule, pull the lever down to load it into the mechanism, then press one of the buttons to tell it to prime itself. After a minute you can them press either of the large cup or the small cup buttons, and your coffee will be delivered.

To automate this with an alarm clock there is no necessity to operate the lever, it’s safe to leave loading a capsule to the user. Therefore all the clock has to do is trigger the process by operating the buttons. A quick investigation with a multimeter on the button PCB found that the voltage present was 15 V, well above the logic level of the STM32F469 board slated for the clock. Thus a simple circuit was devised using a MOSFET to do the switching.

Finally, the clock software was created for the STM32F469. The chip’s 2D graphics acceleration hardware and the development board’s high quality display make for a very slick interface indeed.

You can see the resulting clock in the video below the break. It’s an alarm clock coffeemaker we’d be proud to have beside our beds, but there’s one slight worry. On a mains-powered device like the Nespresso the low voltage rails are not always mains-isolated, and it’s not clear whether or not this is the case. Maybe we’d have incorporated an opto-isolator, just in case.

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Wake Up With A NeoPixel Sunrise Alarm Clock

August 11, 2016 by Kristina Panos 7 Comments

Like many of us, [Lee] wakes up every morning grumpy and tired. Once he decided to try to do something about it, he settled on making a sunrise alarm clock using NeoPixels. Over the course of thirty minutes the clock illuminates 60 NeoPixels one by one in blue mode to simulate a sunrise.

The clock has three modes: 30-minute sunrise, analog time display, and a seconds counter that uses the full RGB range of the LEDs to light up one for each passing second. It runs on an Arduino Pro Mini knockoff and an RTC module for the sake of simplicity. [Lee] chained NeoPixel strips together in five rows of eight, which allowed him to use a 3×5 font to display the time. The only other electronics are passives to protect the LEDs.

NeoPixels are great, but powering them becomes an issue pretty quickly. [Lee] did the math and figured that he would need 3.4 A to drive everything. He found a 3-outlet USB power adapter that delivers 3.4 A total while shopping at IKEA for an enclosure. [Lee] took his first Instructable from beginner to intermediate level by cracking the adapter open and using two of the USB ports wired in parallel to provide 5 V at 3.4 A. [Lee] has the code available along with detailed instructions for replicating this build. Be sure to check out the demo after the break.

We love a good clock build around here, especially when they involve Blinkenlights. For those less interested in building an alarm clock, here’s a word clock that pulls time and weather data with an ESP8266.

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Motorized Music Box Cranks Out Stairway To Heaven

May 31, 2016 by Kristina Panos 20 Comments

[Bokononestly] found a lil’ music box that plays Stairway to Heaven and decided those were just the kinds of dulcet tones he’d like to wake up to every morning. To each his own; I once woke up to Blind Melon’s “No Rain” every day for about six months. [Bokononestly] is still in the middle of this alarm clock project right now. One day soon, it will use a *duino to keep track of the music box’s revolutions and limit the alarm sound to one cycle of the melody.

[Bokononestly] decided to drive the crank of the music box with a geared DC motor from an electric screwdriver. After making some nice engineering drawings of the dimensions of both and mocking them up in CAD, he designed and printed a base plate to mount them on. A pair of custom pulleys mounted to the motor shaft and the crank arm transfer motion using the exact right rubber band for the job. You can’t discount the need for a big bag ‘o rubber bands.
In order to count the revolutions, he put a wire in the path of the metal music box crank and used the body of the box as a switch. Check out the build video after the break and watch him prove it with the continuity function of a multimeter. A clever function that should at some point be substituted out for a leaf switch.

We’ve covered a lot of cool clock builds over the years, including one or two that run Linux. And say what you will about Stairway; it’s better than waking up to repeated slaps in the face.

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Simone Does Strange Things With Motors And Servos

December 29, 2015 by Adam Fabio 52 Comments

If DC motors are the “Hello World” of making things move, servo motors are the next logical step. [Simone Giertz] is following this exact path with the Wake-up Machine and her newly released Chopping Machine. [Simone] discovered that the best way to wake up in the morning is to be repeatedly slapped in the face by a robot. The Wake-up Machine was custom designed to do exactly that. Who could sleep through being repeatedly slapped in the face? A beefy gearmotor from ServoCity spins a Halloween prop arm round and round, providing “refreshing” slaps.

The system is triggered by an alarm clock. The clock’s alarm output is connected to an Arduino Uno. The Uno then activates a relay, which spins up the motor. [Simone] realizes that she could have skipped the Arduino here, but it was the path of least resistance in for this project. If the slapping hand isn’t enough to get you going, the Wake-up machine does have a secret weapon: It may just grab your hair, turning a video shoot into a painful ordeal.

Simone’s latest project is the Chopping Machine. ServoCity must have liked her first videos, as they’ve sponsored her for this project. The machine consists of two knives that … well, chop. Two high-powered servos are controlled by an Arduino Nano. The servos raise spring-loaded knives, which then drop down, chopping vegetables, fingers, and anything else in their path. The whole machine is built with aluminum channel stock, and a huge wooden cutting board. Of course, just building the machine wasn’t enough. [Simone] filmed a parody infomercial for any perspective Chopping Machine buyers, and to put fear in the heart of anyone named Chad.

Click past the break for a couple of [Simone’s] vlogs describing the machines.

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