Zigbee-Based Wireless Arduinos, Demystified

November 29, 2017 by 15 Comments

Hackday regular [Akiba] is working on a series of video tutorials guiding newbies into the world of the 802.15.4 wireless protocol stack — also known as ZigBee. So far, his tutorials include a “getting started with chibiArduino”, his own Arduino-based wireless library, as well as a more basic tutorial on how radio works.

[Akiba] already made a name for himself though a large number of wireless projects, including his Saboten sensor boards, which are ruggedized for long-term environmental monitoring. The Saboten boards use the same wireless stack as his Arduino-compatible wireless development boards, his Freakduino products. The latest version features an ATmega 1284P with 8x the RAM and 4x the flash of the older, 328P-based Freakduinos. It comes in both 900 MHz and 2.4 GHz and there’s also a special 900 Mhz “Long Range” variant. The boards include some great power-saving features, including switchable status LEDs and on-board battery regulation circuity allowing one to run a full year on two AA cells while in sleep mode. They also have a USB stick configuration that is great for Raspberry Pi projects and for running straight from the PC.

For more [Akiba] goodness, check out our colleague [Sophi]’s SuperCon interview with him as well as our coverage of his Puerto Rico lantern project.

Intellibuoy Keeps Track Of The Water

November 29, 2017 by 14 Comments

With world oceans ranging in cleanliness from pretty nasty to OMG, we need to get a handle on what exactly is going on. High School students from Hackensack, NJ built the Intellibuoy, a floating water quality sensor. The buoy has an anemometer and digital rain gauge up top, as well as a LED beacon to comply with maritime regulations.

Flotation is provided by a framework of sealed 3/4″ and 3″ PVC pipes that look strong enough to protect the electronics from a casual boat-bump. High above the water (under ideal conditions) there is the waterproof control box, packing two Arduino UNOs which listen to the sensors. A turbidity sensor measures how much silt is in the water; the other sensors measure Ph, dissolved oxygen, and temperature. The sensor pod is suspended inside a double ring of PVC for maximum protection. Each ‘Duino also has a SD card shield that stores the data of the respective sensors.

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Gesture Keyboard For Universal Input

November 29, 2017 by 14 Comments

Keyboards are currently the most universally accepted computer input devices. They may be wired, wireless, or virtual, but the chances are that you’re within a few centimeters of a keyboard right now. [Federico Terzi] built a prototype from an Arduino and an accelerometer which conceptually resembles writing in Palm’s old Graffiti, though this version is performed in mid-air with a handheld instead of a little square at the bottom of an LCD screen.  He can also operate wirelessly with a Bluetooth module and battery.

The task of the Arduino is to take data from the accelerometer and feed it to the computer whenever a 12mm switch is pressed. Each letter is individually learned by his Python code and scikit-learn’s Support Vector Machine. There’s nothing holding a user back from giving single-letter commands to your favorite programs. For example, it would be possible to give a thumbs-up in meatspace when you want to upvote or covering your ears could mute the audio.

We love keyboard hacks like this mechanical macro keyboard, a minimal and elegant USB Morse key(board), and Brian Benchoff’s open love-letter to mechanical keyboards.

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Friday Hack Chat: Reverse Engineering The Digital Compact Cassette

November 29, 2017 by 33 Comments

For this week’s Hack Chat, we’re talking about reverse engineering the Digital Compact Cassette. Why should we care about an obsolete format that was only on the market for four years?  Because if a copy of the Spin Doctor’s Pocket Full of Kryptonite costs $50 USD on the used market, it has to be good.

In the early 1990s, several different digital magnetic tape formats came onto the scene. The MiniDisc was magneto-optical, yes, but back in the day it was amazing for recording bootlegs. DAT also appeared in the early 90s, and it was a godsend for recording studios. There was another format introduced in 1992, the Digital Compact Cassette. It was backward compatible with standard audio cassettes, an important feature, because no one would want to replace their entire cassette-based music collection with a new-fangled digital format. That would be just lunacy.

Our guest for this week’s Hack Chat will be [Jac Goudsmit], prolific creator on Hackaday.io, with projects ranging from the L-Star Software Defined 6502 Computer to a GPS Controlled FischerTechnik Clock. [Jac] grew up on a PET 2001, and in the years since he’s worked on projects ranging from motion control systems for lithography equipment, pick and place machines, and even at a Radio Shack. In this Hack Chat, he’ll be discussing the history of the Digital Compact Cassette, the behind the scenes on how stereo PCM is recorded to tape, and other topics like the difference between CS/EE careers in the Netherlands and the USA.

join-hack-chatOur Hack Chats are live community events on the Hackaday.io Hack Chat group messaging. Our Hack Chats usually happen on Fridays at Noon, so buckle up because this is going down Friday, December 1, at 12:00 PST. What time is that where you live? Who cares! Here’s a time zone converter!

Click that speech bubble to the left, and you’ll be taken directly to the Hack Chat group on Hackaday.io.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Mike Ossmann And Dominic Spill: IR, Pirates!

November 29, 2017 by 6 Comments

Mike Ossmann and Dominic Spill have been at the forefront of the recent wave of software-defined radio (SDR) hacking. Mike is the hardware guy, and his radio designs helped bring Bluetooth and ISM-band to the masses. Dominic is the software guy who makes sure that all this gear is actually usable. The HackRF SDR is still one of the best cheap choices if you need an SDR that can transmit and receive.

So what are these two doing on stage giving a talk about IR communication? Can you really turn traffic lights green by blinking lights? And can you spoof a TV remote with a cardboard cutout, a bicycle wheel, and a sparkler? What does IR have to do with pirates, and why are these two dressed up as buccaneers? Watch our video interview and find out, or watch the full talk for all of the juicy details.

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Ask Hackaday: How On Earth Can A 2004 MP3 Player Read An SDXC Card?

November 29, 2017 by 80 Comments

What were you doing in 2004? Can you even remember 2004? Maybe it’s like the old joke about the 1960s, if you can remember it, you weren’t really there, man. Cast your mind back, [Lance Armstrong] was winning the Tour de France, and SpaceShipOne made it into space.

[Gregg Eshelman], wrote to us to say that in 2004 he bought an MP3 player. Ask your parents about them, they were what hipsters used before they had cassette tapes: portable music players that everyone thought were really cool back then, onto which music didn’t come from the Internet but had to be manually loaded from a computer.

Jokes about slightly outdated consumer electronics aside, [Gregg]’s player, a GPX MW3836, turned out to be a really good buy. Not only does it still work, it packs an unexpected bonus, it reads 64Gb SD cards when they are formatted as FAT32. This might not seem like a big deal at a cursory glance, but it’s worth considering a little SD card history.

Back when the GPX was made, the maximum capacity of an SD card was 2Gb, a figure that must have seemed huge when the standard was created, but by the middle of the last decade was starting to look a little cramped. The GPX player is designed to only read these original 2Gb cards. In the years since then there have been a couple of revisions to the standard, SDHC, and SDXC, which have given us the huge cards we are used to today. Many other devices from the 2Gb SD era, made before SDHC and SDXC existed, cannot read the modern cards, yet [Gregg]’s GPX can.

Hackaday’s readership constantly amaze us with the sheer breadth of their knowledge and expertise, so we are sure that among you reading this piece will be experts on SD card standards who can shed some light on this mystery. Why can a player designed for the original SD card standard read the much newer cards when other contemporary ones can not? [Gregg] would love to know, and now our curiosity has been whetted, so would we.

If you think you’ve heard [Gregg]’s name before, it might be for his expertise in resin casting automotive parts.

SD card image: Andreas Frank (CC BY 2.5).

Coin Cell Challenge: Use Coin Cell, Win Prizes

November 29, 2017 by 74 Comments

Today, we’re calling all hackers to do the most with a single coin cell. It’s the Coin Cell Challenge, and we’re looking for everything from the most low-power electronics to a supernova in a button cell battery.

Electronics are sucking down fewer and fewer amps every year. Low power is the future, and we’re wondering how far we can push the capabilities of those tiny discs full of power. The Coin Cell Challenge is your chance to plumb the depths of what can be done with the humble coin cell.

This is a contest, and as with the tradition of the Open 7400 Logic Competition and the recent Flashing Light Prize, we want to see what the community can come up with. The idea is simple: do something cool with a single coin cell and you’ll secure your fifteen minutes of fame and win a prize.

Three Challenges

To kick this contest off, we’re opening up three challenges to all contenders to the world heavyweight champion of button cell exploits. The first, the Lifetime Award, will go to whoever can run something interesting the longest amount of time on a coin cell. The Supernova Award is the opposite – what is the most exciting thing you can do with a button cell battery, lifetime be damned? The Heavy Lifting Award will go to the project that is the most unbelievable. If you think you can’t do that with a coin cell battery — lifting a piano or starting a car, for example — odds are you probably can. We want to see it.

Prizes and Rules

All Hackaday hardware hacking challenges need prizes, and for this one, we’re rolling out the red carpet. We’re offering up cash prizes for the top coin cell hacks. There are three $500 USD cash prizes, one for each winner of the Lifetime, Supernova, and Heavy Lifting awards. We’re not stopping there, because the top twenty builds overall will each receive $100 in Tindie credit, where the winners can cash in on some artisanal electronics sold by the people who design them.

What do you have to do to get in on this action? First, you need to build something. This something must be powered by nothing more than a single coin cell battery and must include some type of electronics. We also want this to be Open Source, and you’ll need to start a project on hackaday.io. The full rules are available over here, but don’t wait — the deadline for entry is January 8th, 2018.

We’re excited to see what the community comes up with, and who will find a production coin cell that’s the size of a dinner plate. This is going to be a great contest with overheating coin cells and tiny bits of metal flying across the room. This is going to be a contest filled with blinkies and wireless devices that run for far, far too long. Someone is going to misread the rules and tape together a meter tall pile of coin cells. It’s going to be awesome, so start your project now.