You should already know about the 2015 Hackaday Prize, but have you submitted your entry yet? All it takes to get started is talking about one idea you have to address a problem faced by a large number of people. To help get the ball rolling we’re giving away some prizes to three entries that discuss possible solutions to Environment-Related problems.
For your chance at this week’s goodies all you need to do is document your idea on Hackaday.io and tag it “2015HackadayPrize”.
This Week’s Prizes:
On Monday, March 30th we’ll take a look at all the entries tagged 2015HackadayPrize and choose three that best fit the topic of Environment-Related. The best will receive the SmartMatrix 32×32 RGB LED matrix along with a Teensy 3.1 to drive it. The next pick will receive a Bus Pirate and probe cable. The final prize will be a Hackaday Robot Head Tee.
An Idea is All You Need for Entry
We’re not messing with you; all you need to win these early prizes is an idea. One of the most powerful pieces of the Hackaday Prize is the pollination of thought. Your idea might be the tipping point for someone else’s breakthrough or vice-versa. Start a project on Hackaday.io and add the tag “2015HackadayPrize”.
Pictured to the right is a whiteboard sketch by [MechaTweak] which illustrates one very simple shower water-saving idea (we think this was prompted by our column on the topic last week). The idea here is that instead of running water down the shower drain as you wait for it to heat up, the water cold be sequestered in a holding tank and used for flushing the toilet the rest of the day. This will certainly be in the running as it addresses the issue of water conservation. Going along with our Environment-related topic you might also tackle alternative energy production, helping detect or curb pollution, making recycling easier, reducing waste, etc.
As we move along we’ll be awarding bigger and better prizes. Submitting an idea now will give you an early start on your planning. You’ll still be eligible for future prizes, and you may submit as many entries as you like.
We don’t find smartwatches to be supremely usable yet. This one sets a definition for usefulness. The Enigma machine is of course the cipher process used by the Germans during World War II. This Enigma Machine wristwatch is not only functional, but the appearance is modelled after that of the original machine. With the speckled gray/black case and the Enigma badge branding [Asciimation] has done a fine job of mimicking the original feel.
Driving the machine is an Arduino Pro Mini. We’ve seen Arduino Enigma Machines in the past so it’s not surprising to see it again here. The user interface consists of an OLED display at 128×64 resolution, three buttons, with a charging port to the right and on/off switch on the left.
The device is demonstrated after the break. Quite a bit of button presses are used to set up each of the three encoder wheels. But that’s hardly avoidable when you’re not committing to a full keyboard. We’re pretty impressed by the functionality of [Asciimation’s] interface considering it’s hardware simplicity.
This seems perfect for kids that are proving to have an interest in engineering. They learn about ciphers, embedded programming, and mechanical design and crafting (this is a hand-sewn leather wristband). Of course if you build one and start wearing it into the office we won’t judge.
Continue reading “Enigma Machine Wristwatch”
Microcontroller Dev Boards have the main hardware choices already made for you so you can jump right into the prototyping by adding peripherals and writing code. Some of the time they have everything you need, other times you can find your own workarounds, but did you ever try just swapping out components to suit? [Andy Brown] documented his process of transplanting the clock crystal on an STM32F4 Discovery board.
Even if you don’t need to do this for yourself, the rework process he documented in the clip after the break is fun to watch. He starts by cleaning the through-hole joints of the crystal oscillator with isopropyl alcohol and then applies some flux paste to each. From there the rest is all hot air. The crystal nearly falls out due to gravity but at the end he needs to pluck it out with his fingers. We’re happy to see others using this “method” as we always feel like it’s a kludge when we do it. Next he grabs the load caps with a pair of tweezers after the briefest of time under the heat.
We’d like to have a little bit of insight on the parts he replaces and we’re hoping there are a few crystal oscillator experts who can leave a comment below. [Andy] calculates a pair of 30pf load caps for this crystal. We understand the math but he mentions a common value for board and uC input capacitance:
assuming the commonly quoted CP + CI = 6pF
So we asked and [Andy] was kind enough to share his background on the topic:
It’s a general “rule of thumb” for FR4 that the stray capacitance due to the traces on the board and the input (lead) capacitance of the the MCU is in in the range of 4-8pF. I’m used to quoting the two separately (CP,CI) but if you look around you’ll see that most people will combine the two and call it just “CP” and quote a value somewhere between 4 and 8pF. It’s all very “finger in the air” and for general purpose MCU clocks you can get away picking the mid-value and be done with it.
That leaves just one other question; the original discovery board had an in-line resistor on one of the crystal traces which he replaces with a zero ohm jumper. Is it common to include a resistor and what is the purpose for it?
Continue reading “Swapping Dev Board Crystals to Suit Your Needs”
It’s easy to get sucked into the increasing the complexity when sometimes the craftsmanship can be what makes the project. [Alex Weber] proves the point with his minimalist marble machine. There are no death-defying twists and turns, no convoluted path forks or overly-complex lifting mechanisms. This is about a clean and simple design that looks amazing whether running or stationary.
For the uninitiated, marble machines route marbles (or quite often steel ball bearings) through a set of paths usually guided by gravity for the delight of onlookers. Traditionally, making them complicated is the point. Take this offering which highlights years worth of marble machine builds all exercising different concepts. Sometimes they occupy entire rooms. We’ve seen them make a clock tick. And who can forget marble-based flip-flops that combine to form things like binary adders?
Have we scared you off from building these yourself yet? No, that’s the entire point of this one… it can be excruciatingly simple, while elegantly crafted. Check out the video demo below to see how one oval, one battery, and one motor have no problem bringing a smile to your face.
Continue reading “Your Marble Machine Doesn’t Need to Change the World”
[Nick Sayer] falls into the “would rather build it than buy it” category. This particular project is a clone of a fast electric vehicle charger. There are commercially available versions sold under the Quick 220 brand name. The idea is that for fast charging, some electric vehicles call for a 240V outlet and Americans without electric cars often don’t have one. If they do it’s for an appliance like a stove or clothes dryer and probably not found in the garage.
The device uses two hot and one ground to supply the 240V output which is, in some business where there is three phase power this will be closer to 208V but should still work. Obviously you shouldn’t be doing this unless you know exactly how it works, and we applaud [Nick] for airing these hazards while at the same time supplying the knowledge behind the concerns.
Two inputs for the beefy converter are supplied from outlets not just on separate circuits, but on two circuits whose hot lines are 180 degrees out of phase. That means identifying where there are two plugs, not protected by GFCI outlets or breakers, which are on two separate hot lines of split phase power. To protect the user, [Nick] designed in a set of relays which kill the circuit when one of the two supplies is unplugged. A system that didn’t have these protections would have mains voltage on the prongs of the disconnected plug.
We’ve seen very few car charging hacks. If you know of one, or have been working on your own, let us know!
Wires? Where this LED scroller is going we don’t need wires. Well, except for power but everything needs power. The 90×7 LED marquee hangs over the entrance to NYC Resistor’s laser cutter room. Thanks to a Spark Core and a bit of work from [Trammell Hudson], the sign is working and attached to the network.
The original unit called for an RS485 connection for input. Other than that there wasn’t really a reason it had been collecting dust. Closer inspection of the internals proved that the display is driven exactly as you would expect: transistors for the rows and shift registers for the columns. Well, actually the columns are split into separate shift registers for the even and odd but that doesn’t complicate things too much. GPIO takes the seven row-driving transistors, two shift register clocks, data, latch, and enable for a total of twelve pins.
The Spark Core completely replaces the Atmel 80C32X2 and its RTC by pinging the network for UTC time synchronization once per day.
[via NYC Resistor]
Obviously the wavelength of a laser can’t be measured with a scale as large as that of a carpenter’s tape measure. At least not directly and that’s where a Compact Disc comes in. [Styropyro] uses a CD as a diffraction grating which results in an optical pattern large enough to measure.
A diffraction grating splits a beam of light up into multiple beams whose position is determined by both the wavelength of the light and the properties of the grating. Since we don’t know the properties of the grating (the CD) to start, [Styropyro] uses a green laser as reference. This works for a couple of reasons; the green laser’s properties don’t change with heat and it’s wavelength is already known.
It’s all about the triangles. Well, really it’s all about the math and the math is all about the triangles. For those that don’t rock out on special characters [Styropyro] does a great job of not only explaining what each symbol stands for, but applying it (on camera in video below) to the control experiment. Measure the sides of the triangle, then use simple trigonometry to determine the slit distance of the CD. This was the one missing datum that he turns around and uses to measure and determine his unknown laser wavelength.
Continue reading “Measure Laser Wavelength with a CD and a Tape Measure”