The (Copper) Crystal Method

July 3, 2016 by Al Williams 43 Comments

One of the staples of kitchen chemistry for kids is making sugar crystals or rock candy. Why not? It is educational and it tastes good, too. [Science with Screens] has a different kind of crystal in mind: copper crystals. You can see the result in the video below.

To grow pure metal crystals, he used copper wire and copper sulfate. He also used a special regulated power supply to create a low voltage to control the current used to form the crystal. The current needed to be no more than 10mA, and an LM317 holds the voltage constant. However, that regulator only goes as low as 1.25V, so diodes cut a volt off the output.

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Brasilia Espresso Machine PID Upgrade Brews Prefect Cup Of Energy

July 3, 2016 by Moritz Walter 20 Comments

Coffee, making and hacking addictions are just bound to get out of control. So did [Rhys Goodwin’s] coffee maker hack. What started as a little restoration project of a second-hand coffee machine resulted in a complete upgrade to state of the art coffee brewing technology.

The Brasilia Lady comes with a 300 ml brass boiler, a pump and four buttons for power, coffee, hot water and steam. A 3-way AC solenoid valve, wired directly to the buttons, selects one of the three functions, while a temperamental bimetal switch keeps the boiler roughly between almost there and way too hot.

To reduce the temperature swing, [Rhys] decided to add a PID control loop, and on the way, an OLED display, too. He designed a little shield for the Arduino Nano, that interfaces with the present hardware through solid state relays. Two thermocouples measure the temperature of the boiler and group head while a thermal cut-off fuse protects the machine from overheating in case of a malfunction.

Also, the Lady’s makeup received a complete overhaul, starting with a fresh powder coating. A sealed enclosure along with a polished top panel for the OLED display were machined from aluminum. [Rhys] also added an external water tank that is connected to the machine through shiny, custom lathed tube fittings. Before the water enters the boiler, it passes through a custom preheater, to avoid cold water from entering the boiler directly. Not only does the result look fantastic, it also offers a lot more control over the temperature and the amount of water extracted, resulting in a perfect brew every time. Enjoy [Rhys’s] video where he explains his build:

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Hackaday Prize Entry: A Minimal ATtiny Voltage And Frequency Counter

July 2, 2016 by Jenny List 4 Comments

Sometimes when you build something it is because you have set out with a clear idea or specification in mind, but it’s not always that way. Take [kodera2t]’s project, he set out to master the ATtiny series of microcontrollers and started with simple LED flashers, but arrived eventually at something rather useful. An ATtiny10 DVM and DFM all-in-one with an i2c LCD display and a minimum of other components.

The DFM uses the ATtiny’s internal 16 bit timer, which has the convenient property of being able to be driven by an external clock. The frequency to be measured drives the timer, and the time it returns is compared to the system clock. It’s not the finest of frequency counters, depending as it does on the ATtiny’s clock rather than a calibrated crystal reference, but it does the job.

The results are shown in the video below, and all the code has been posted in his GitHub repository. We can see that there is the basis of a handy little instrument in this circuit, though with the price of cheap multimeters being so low even a circuit this minimal would struggle to compete on cost.

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Mechanical Horse-Bike

July 2, 2016 by Elliot Williams 18 Comments

Oh [Rodger Cleye]! You had us at “unicycle, duct tape, styrofoam, and tie wraps”. But watching the horse-bike in action (video below) is just about enough for us to go out and make one ourselves. (For our child, naturally. We’re far too dignified.)

If you trawl around [Rodger]’s YouTube channel, you’ll see no end of odd motorized vehicles. Like last year’s motorized horse project, or this stormtrooper speeder. But there’s just something about the way that the horse’s legs move along with the rider that is slightly more enchanting. (That’s the “unicycle” part of the build.) And, we assume, the rider gets a little bit more exercise to boot.

We’ve featured a few builds of [Rodger]’s before, including his motorized couch build that’s obviously controlled from the seat-mounted coconut, and of course a pneumatic Boba Fett rocket.

Ham Radio WiFi

July 2, 2016 by Al Williams 21 Comments

Many Ham Radio operators in the United States participate in Field Day. This is an annual exercise where radio operators are encouraged to set up stations in conditions that might occur after a natural disaster. Usually, this means taking over some park or camp site, bringing generators, portable equipment, and making it all work for the weekend before you tear it back down.

It isn’t much of a Field Day without electricity. That’s why most stations use a generator, solar cells, or even batteries. Today, though, you probably need an Internet-connected computer to do logging and other features. [HamRadioConcepts] has a video (see below) that shows how they grabbed Internet from a distance for their Field Day site.

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Venduino Serves Snacks, Shows Vending Is Tricky Business

July 2, 2016 by Dan Maloney 19 Comments

Seems like just about every hackerspace eventually ends up with an old vending machine that gets hacked and modded to serve up parts, tools, and consumables. But why don’t more hackerspaces build their own vending machines from scratch? Because as [Ryan Bates] found out, building a DIY vending machine isn’t as easy as it looks.

[Ryan]’s “Venduino” has a lot of hackerspace standard components – laser-cut birch plywood case, Parallax continuous rotation servos, an LCD screen from an old Nokia phone, and of course an Arduino. The design is simple, but the devil is in the details. The machine makes no attempt to validate the coins going into it, the product augurs are not quite optimized to dispense reliably, and the whole machine can be cleaned out of product with a few quick shakes. Granted, [Ryan] isn’t trying to build a reliable money-making machine, but his travails only underscore the quality engineering behind modern vending machines. It might not seem like it when your Cheetos are dangling from the end of an auger, but think about how many successful transactions the real things process in an environment with a lot of variables.

Of course, every failure mode is just something to improve in the next version, but as it is this is still a neat project with some great ideas. If you’re more interested in the workings of commercial machines, check out our posts on listening in on vending machine comms or a Tweeting vending machine.

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Hacklet 114 – Python Powered Projects

July 2, 2016 by Adam Fabio 5 Comments

Python is one of today’s most popular programming languages. It quite literally put the “Pi” in Raspberry Pi. Python’s history stretches back to the late 1980’s, when it was first written by Guido van Rossum. [Rossum] created Python as a hobby project over the 1989 Christmas holiday. He wanted a language that would appeal to Unix/C hackers. I’d say he was pretty successful in that endeavor. Hackers embraced Python, making it a top choice in their projects. This week’s Hacklet focuses on some of the best Python-powered projects on Hackaday.io.

We start with [Jithin] and Python Powered Scientific Instrumentation tool, his entry in the 2015 Hackaday Prize. [Jithin] has created an “electronics lab in a box” style tool that can compete with commercial products with price tags in the thousands. Python Powered Scientific Instrumentation tool uses simple microcontroller powered hardware to create programmable gain amplifiers, waveform generators, LCR meters, CC sources and more. The microcontroller handles all the real-time operations. Data processing happens on a connected PC running Python scripts. Popular Python libraries like Scipy make signal processing and waveform displays easy.

Next up is [Bill Peterson] with jamPi. [Bill] loves his music keyboard, but hates having to lug around a laptop, audio interface, and all the associated cables. He needed a device which would be as flexible as a PC-based synthesizer, but as simple and compact as a MIDI sound module. JamPi does all this and more. [Bill] is using fluidsynth to generate sound. The control and interface software is handled in Python with the help of the fluidsynth.py module. All this functionality is wrapped up in a simple box with a 2 line character LCD. Now [Bill] is ready to jam anytime, anywhere.

Next is [i.abdalkader] with OpenMV, his entry in the 2014 Hackaday Prize. [i.abdalkader’s] goal was to create “the Arduino of machine vision”. He’s well on his way to accomplishing that. In 2015, OpenMV had a successful Kickstarter campaign. After a few manufacturing glitches, customers are now receiving their devices. OpenMV is a low-cost Python-powered machine vision device. An ARM microcontroller coupled to a simple image sensor makes up the core of the device. The camera is programmed in MicroPython, with the help of many image processing libraries created by the OpenMV team. [i.abdalkader] even created his own IDE using Glade and PyGTK.

Finally we have [osannolik] with Calibration and Measurement Tool. Have you ever want to display a few debug parameters from your embedded project, but didn’t have the display real estate (or any display at all)? What about changing a parameter without pulling out your JTAG setup and firing up your debugger? [Osannolik] has created a simple Python powered PC-based front end which can be used as a Swiss army knife for developing embedded systems. Variables can be displayed in real-time, parameters changed. Even graphs are available thanks to pyqtgraph.

If you want more Python-powered goodness, check out our new Python-powered project list! Did I miss your project? Don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!