Embed With Elliot: March Makefile Madness

March 11, 2016 by 36 Comments

The make tool turns the big 4-0 next month, and we thought we’d start up the festivities early. In a two-part series, I’ll cover some of the make background that I think is particularly useful, and then focus on microcontroller-specific applications. If you’re still cut-and-pasting a general purpose makefile to run your toolchain, hopefully you’ll get enough insight here to start rolling your own. It can be a lot simpler than it appears!

Just as soon as the C programming language was invented, and projects started to get a little bit bigger than a “hello world”, it became obvious that some tool was needed to organize and automate compilation. After all, if you’ve got a program that’s spread over a number of files, modules, or libraries, it’s a hassle to have to re-compile them all any time you make a change to just a single section of code. If some parts haven’t changed, you’re just wasting time by re-compiling them. But who can keep track of all of this? Make can!

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Join Us At The Greatest 3D Printing Festival On Planet Earth

March 11, 2016 by 10 Comments

Winter is hanging on like clinical depression, which means it’s that time again for the greatest 3D-printing festival on the planet Earth. It’s time for the Midwest RepRap Festival, next weekend, March 18-20th in Goshen, Indiana.

I can’t explain why, but for some reason the Midwest RepRap Festival is an oasis of building, doing, and hacking right in the middle of the county fairgrounds for Elkhart County, Indiana. It’s free for everyone to attend. The event isn’t choked with vendors, leaving the people who actually do stuff left to fight over a few picnic tables on the outskirts of the venue. It is, by far, the most community-centered event we go to every year.

If you’re wondering what you can expect at a 3D printer convention in the middle of nowhere, check out a few of the posts we’ve published from MRRF over the last few years. We’ve seen 3D printed waffles, resin casting with 3D printed molds, bizarre movement platforms, Bioprinting, and stuff from Lulzbot. That’s just the stuff that has deserved its own Hackaday post: we’ve seen the world’s largest 3D printed trash can, R2D2, battle droids (it’s even money if BB-8 is going to show up this year), a Printer made out of K’nex, and the most beautiful 3D printer we’ve ever seen. There was a T-shirt cannon powered by 300 psi shop air.

Every year I write a post announcing that we’ll be heading to MRRF next week, simultaneously praising the event as one of the greatest ‘maker’ and ‘DIY’ meetups, while pointing out the local WalMart parking lot has a place to park horse-drawn buggies. Both observations are true. For one weekend a year, Goshen, Indiana is the place everyone reading Hackaday should go to, and that is why we are once again proud to sponsor this glorious event.

Beyond Measure: Instrumentation Essentials

March 11, 2016 by 34 Comments

The physical world is analog and if we want to interface with it using a digital device there are conversions that need to be made. To do this we use an Analog to Digital Converter (ADC) for translating real world analog quantities into digital values. But we can’t just dump any analog signal into the input of an ADC, we need this analog signal to be a measurable voltage that’s clean and conditioned. Meaning we’ve removed all the noise and converted the measured value into a usable voltage.

Things That Just Work.

This is not new information, least of all to Hackaday readers. The important bit is that we rely on these systems daily and they need to work as advertised. A simple example are the headlights in my car that I turned on the first night I got in it 5 years ago and haven’t turned off since. This is not a daytime running lights system, the controller turns the lights on when it’s dark and leaves them off during the day. This application falls into the category of things that go largely unnoticed because simply put: They. Work. Every. Time. It’s not a jaw dropping example but it’s a well implemented use of an analog to digital conversion that’s practical and reliable.

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Figure 1

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Endless Pancakes

March 11, 2016 by 40 Comments

Sometimes along comes a machine so simple yet so alluring in what it does and how it achieves its aim that you just want one. Doesn’t matter what it does or indeed whether ownership is a practical proposition, you wish you could have one in your possession.

What machine could trigger this reaction, you ask? [Robbie Van Der Walt] and [Christiaan Harmse] have the answer, their machine performs the simple but important task of cooking an endless pancake. A hopper dispenses a layer of pancake batter onto a slowly rotating heated roller that cooks the ribbon of pancake on one side, before it is transferred to another roller that cooks the other side. It seems simple enough yet the simplicity must hide a huge amount of product refinement and probably many miles of lost pancake. Pancakes it seems are a traditional South African delicacy, evidently they must have king-sized appetites to satisfy.

In the video below (Afrikaans, English subtitles) they make an attempt at a world record for the longest ever pancake, though sadly they don’t seem to appear in a Guinness  World Records search so perhaps they didn’t achieve it. Still, their machine is a work of art, and we applaud it. Continue reading “Endless Pancakes” →

Finger Print Scanners Really Aren’t That Secure

March 11, 2016 by 52 Comments

Maybe you suspected this already, but researchers at MSU Computer Science just published a paper explaining just how easy it is to spoof a fingerprint scanner with a ink-jet printed scan of a finger.

We’re not talking about casting a new finger using superglue or anything, but rather using conductive ink you can literally print — on paper. A paper-printed-fingerprint that will unlock your smartphone. We’ve already told you fingerprints suck for security, but hopefully this drives the point home.

[Kai Cao] and [Anil K Jain] released this paper (Direct PDF link) outlining their technique. Using an existing scan of a fingerprint (which can be taken from your phone’s scanner), the image is mirrored, and then printed using a regular ink-jet printer, with all of its color cartridges replaced with AgIC4 silver conductive ink.
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Electric Skateboard Reaches Neck-Breaking Speeds

March 10, 2016 by 25 Comments

[Mischo Erban], a Canadian speed-freak, just broke a world record on an electric skateboard. 59.55mph! That’s almost 100km/h.

We’ve covered a lot of electric skateboards over the years, as well as some commercial versions — like the Boosted Board, one of the few actual Kickstarter success stories — and of course, people have hacked them as well. But this board from Next Generation Vehicles (NGV), seems to have taken speed to the next level.

Made by a Slovenian tech startup, the board features direct drive motors built into custom wheels. The article is a bit light on details, but we imagine they must be a few kW each in order to reach those speeds. No mention of a range (we can’t imagine it’d be very far at those speeds), but it is just a prototype.

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Banish Dangerous Shadows Under Kitchen Cabinets

March 10, 2016 by 30 Comments

[nebulous] has a lot of problems with his kitchen cabinets. Aside from a noted lack of micro-controllers, he was especially suspicious of the dark spaces under them. Anything could be hiding there.

The core of the project is a $10 Arduino-compatible esp8266 board from digistump. The board is powered by the five volt regulator of an L298N motor driver module hooked to a power-supply. All this controls a set-of LED strips adhered to the underside of the cabinets with the traditionally bad adhesive strips with which they come standard. We can predict an hour spent bent awkwardly cursing at them, a hot-glue gun in one hand, in [nebulous]’s future. The whole set-up is housed in a SparkFun cardboard box above the microwave. You can barely tell it’s not a commercial product.

We’re not certain if we like a future where even our cabinetry has an IP address. However, this is a good weekend project that could make all our cabinetry brighter, safer, and more connected.