Make A Cheap (And Dangerous) Automated Flamethrower

Nothing lights up the night like a quick blast from a flamethrower, but there is a reason why you can’t buy them in the Halloween decoration aisle at Target. They are dangerous, for fairly obvious reasons. [Erco] seems to have no particular fear of death, though, and he shows how you can build a simple flamethrower with a small candle, a servo, Arduino and a can of hairspray. Tresemme Extra Strong Hold, in particular, although we don’t think the exact type matters that much. All he did was to mount the candle in front of the hairspray, then mount the servo so the arm presses the spray head down. The candle does the rest, lighting the highly flammable propellant in the hairspray to produce the flamethrower effect. [Erco] is using four of these, which are co-ordinated to fire in time with music.

This one seems a bit risky. Servos have a habit of locking, and there is nothing stopping these from locking in the open position, or sticking there if the Arduino crashes. A relay or other switch that reverts to an off position when the power is removed would have been more suitable here. Secondly, there is no emergency off switch. [Erco] has wired the Arduino up next to the flamethrower itself, so you are going to have to reach in to disconnect it. That is risky enough, but he also tried a 4-way configuration that would have been impossible to disable in the event of a problem (shown in the accompanying images). Thirdly, there is no fire protection between the can of hairspray and the open flame, so if the spray head melts or fails from the heat, it’s game over. Finally (and most importantly), where are the fire extinguishers? We’d like to hear how you’d build this with safety in mind. Let us know in the comments below.

We’re big fans of flames and explosions: we’ve have seen a couple of Survival Research Laboratory shows and were blown away by their destructive pyrotechnics. But, as SRL head Mark Pauline said in a recent talk, “when things blow up at an SRL show, it’s on purpose”.

Continue reading “Make A Cheap (And Dangerous) Automated Flamethrower”

WiFi Fob Acquaints OLED With ESP

When you think of WiFi in projects it’s easy to get into the rut of assuming the goal is to add WiFi to something. This particular build actually brings WiFi awareness to you, in terms of sniffing what’s going on with the signals around you and displaying them for instant feedback.

[0miker0] is working on the project as his entry in the Square Inch Project. It’s an adapter board that has a footprint for the 2×4 pin header of an ESP8266-01 module, and hosts the components and solder pads for a 128×64 OLED display. These are becoming rather ubiquitous and it’s not hard to figure out why. They’re relatively inexpensive, low-power, high-contrast, and require very few support components. From the schematic in the GitHub Repo it looks like 5 resistors and 7 caps.

The video below shows off two firmware modes so far. The first is an AP scan that reads out some information, the second is a weather-display program. Anyone who’s worked with the ESP modules knows that they have the potential to gather all kinds of data about WiFi signals — one of our favorite demos of this is when [cnlohr] used it to create a 3d light painted map of his WiFi signal strength. Chuck a rechargeable LiPo on this thing, tweak the example code for your needs, and you have a new gadget for wardriving-nouveau.

Continue reading “WiFi Fob Acquaints OLED With ESP”

Code Craft: When #define Is Considered Harmful

An icon of Computer Science, [Edsger Dijkstra], published a letter in the Communications of the Association of Computer Machinery (ACM) which the editor gave the title “Go To Statement Considered Harmful“. A rousing debate ensued. A similar criticism of macros, i.e. #define, in C/C++ may not rise to that level but they have their own problems.

Macros are part of the preprocessor for the C/C++ languages which manipulates the source code before the actual translation to machine code. But there are risks when macros generate source code. [Bjarne Stroustrup] in creating C++ worked to reduce the need and usage of the preprocessor, especially the use of macros. In his book, The C++ Programming Language he writes,

Don’t use them if you don’t have to. Almost every macro demonstrates a flaw in the programming language, in the program, or in the programmer.

As C retrofitted capabilities of C++, it also reduced the need for macros, thus improving that language.

With the Arduino using the GNU GCC compilers for C and C++ I want to show new coders a couple of places where the preprocessor can cause trouble for the unwary. I’ll demonstrate how to use language features to achieve the same results more cleanly and safely. Of course, all of this applies equally when you use any of these languages on other systems.

We’re only going to be looking at macros in this article but if you want to read more the details about them or the preprocessor see the GNU GCC Manual section on the preprocessor.

Continue reading “Code Craft: When #define Is Considered Harmful”

Show A Quadcopter Flight On Google Earth For Under Ten Bucks

[Joop Brokking] wanted to know where his quadcopter was and had been. He thought about Google Earth, but assumed it would be difficult to get the GPS data and integrate it with Google’s imagery. But he discovered it was easier than he thought. He wound up spending around $10, although if his ‘copter didn’t already have GPS, it would have been more.

Hardware-wise, [Joop] made a pretty straightforward data logger using a small Arduino (a Pro Mini) and an SD Card (along with an SD breakout board). With this setup, NMEA data from the GPS comes in the Arduino’s serial port and winds up on the SD Card.

Continue reading “Show A Quadcopter Flight On Google Earth For Under Ten Bucks”

Hacklet 80 – Gigahertz Projects

Somewhere between the HF projects many of us have worked on, and the visible light spectrum lies the UHF, EHF, SHF, and THF. That’s Ultra, Extremely, Super, and Tremendously High Frequency for those who aren’t in the know. All of them involve frequencies in the gigahertz and terahertz range. While modern computers have made gigahertz a household term, actually working with signals in the gigahertz frequency range is still a daunting prospect. There have always been an elite group of hackers, makers, and engineers who tinker with projects using GHz frequencies. This week’s Hacklet is about some of the best GHz projects on Hackaday.io!

radar1We start with [Luke Weston] and Simple, low-cost FMCW radar. For years people like Hackaday’s own [Gregory L. Charvat] have been building simplified radar systems and documenting them for the rest of us. [Luke’s] goal is to make radar systems like this even more accessible for the average hacker. He’s put all the specialized parts on one board. Rather than large Mini Circuits modules, [Luke] went with Hittite microwave parts in chip scale packages. Modulation comes from a Microchip MCP4921 mixed signal DAC. The system works, and has demonstrated transmission and reception 5 GHz to 6 GHz bands. [Luke] has even demonstrated detection of objects at close range using a scope.

Continue reading “Hacklet 80 – Gigahertz Projects”

Intel And Arduino Introduce Curie-Based Educational Board

This week, Intel and Arduino are releasing their first product pushed directly on the education market, the Arduino/Genuino 101 board powered by the Intel Curie module.

The Intel Curie Module

genuino101The Arduino/Genuino 101 is the first development platform for the Intel Curie modules which are a recent development from Intel’s Maker and Innovator group. The button-sized Curie is a single package encapsulating microcontroller, Bluetooth, a 6-DOF IMU, and battery charging circuitry; the requisite hardware for anything marketed as a ‘wearable’. The Curie’s brain is a 32-bit Intel Quark microcontroller with 384kB of Flash 80kB SRAM, giving it about the same storage and RAM as a low-end ARM Cortex microcontroller.

Called a module, it needs a carrier board to interface with this hardware. This is where the Arduino/Genuino 101 comes in. This board – the third such collaboration between Intel and Arduino – provides the same form factor and pinout found in the most popular Arduino offering. While the Curie-based Arduino/Genuino 101 is not replacing the extraordinarily popular Arduino Uno and Leonardo, it is going after the same market – educators and makers – at a similar price, $30 USD or €27. For the same price as an Arduino Uno, the Arduino/Genuino 101 offers Bluetooth, an IMU, and strangely the same USB standard-B receptacle.

Intel has further plans in store for the Curie module; In 2016, Intel, [Mark Burnett] of reality television fame, and United Artists Media group will produce America’s Greatest Makers, a reality show featuring makers developing wearable electronics on TV. No, it’s not Junkyard Wars, but until the MacGyver reboot airs, it’s the closest we’re going to get to people building stuff on TV.

Intel’s Prior Arduino Offerings

In 2013, Intel and Arduino introduced the Galileo board, a dev board packed with I/Os, Ethernet, PCIe, and an Intel instruction set. This was a massive move away from all ARM, AVR, or PIC dev boards made in recent years, and marked Intel’s first foray into the world of education, making, and an Internet of Things. In 2014, Intel and Arduino released the Edison, a tiny, tiny board designed for the embedded market and entrepreneurs.

Intel CurieThe Arduino 101 and Genuino 101 – different names for the same thing and the first great expression of arduino.cc’s troubles with trademarks and the Arduino vs Arduino war – are targeted specifically at the ‘maker’ market, however ephemeral and hard to define that is. The form of the Arduino 101 follows directly in the footsteps of the Arduino Uno and Leonardo; The 101 has the same footprint, the same pinout, a single USB port as the Leonardo.

Being the ‘maker market Arduino’, this board is designed to bring technology to the classroom. In a conference earlier this week, [Massimo] framed the Arduino 101 as the educational intersection between technology, coding, art, and design. Students who would not otherwise learn microcontroller development will learn to program an Arduino for art and design projects. The Arduino/Genuino 101 is the board that puts the STEAM in STEM education.

Where the Curie is Going

Intel has big plans for the Curie module, with a few products in the works already. The Intel Edison has made its way into consumer electronics and wearables, including an electronic ski coach that will tell you when to pizza and when to french fry. The Curie will be available independently of the Arduino/Genuino 101, with both products being released in early 2016.

Random Parcel Launches Steganographic Compulsion

A mysterious CD arrives in the mail with a weird handwritten code on it. What should you do? Put it in the computer and play the thing, of course!

Some might be screaming at their screens right now… this is how modern horror films start and before you know it the undead are lurking behind you waiting to strike. Seasonal thrills aside, this is turning into an involved community effort to solve the puzzle. [Johny] published the video and posted a thread on reddit.

We ran a similar augmented reality game to launch the 2014 Hackaday Prize solved by a dedicated group of hackers. It’s really hard to design puzzles that won’t be immediately solved but can eventually be solved with technology and a few mental leaps. When we come across one of these extremely clever puzzles, we take note.

This has all the hallmarks of a good time. The audio spectrogram shows hidden data embedded in the file — a technique known as steganography. There are some real contortions to make meaning from this. When you’re looking for a solution any little hit of a pattern feels like you’ve found something. But searching for the decrypted string yields a YouTube video with the same name; we wonder if they’ve tried to recover steganographic data from that source?

[Johny] mentions that this parcel was unsolicited and that people have suggested it’s a threat or something non-sensical in its entirety. We’re hoping it’s a publicity stunt and we’re all disappointed in the end, because solving the thing is the best part and publicity wouldn’t work if there was no solution.

The bright minds of the Hackaday community should be the ones who actually solve this. So get to work and let us know what you figure out!