Teensy Tiny Arduino Board With An ATtiny85

August 13, 2012 by Brian Benchoff 55 Comments

Planning another Arduino build? If you’re just doing something simple like switching a relay or powering a LED, you might want to think about the Digispark. It’s a very small ATtiny-based Arduino compatible board developed and Kickstarted by [Erik].

The Digispark is based on the very popular Atmel ATtiny85, an 8 pin microcontroller that provides a quarter of the Flash storage and RAM as the ‘official Arduino’ ATMega328p. The lower storage space and RAM doesn’t mean the ’85 is a slouch, though; it can run Arduino code without a hitch, providing six pins for whatever small project you have in mind.

Right now, [Erik]’s Kickstarter is offering three Digisparks for the price of a single Arduino. At that price, it’s cheap enough to leave in a project and not be repurposed after the build is over. [Erik] is also working on a few shields for the Digispark – only RGB LED shield for now, but hopefully he’ll get some more finished by the time the Kickstarter ends.

A Perpetually Powered Wireless Outpost

August 13, 2012 by Brian Benchoff 24 Comments

For [Justin], the topic of remotely powering electronics in the field comes up often. So often in fact he decided to put up a tutorial for powering electronics from solar power and batteries, as well as sending and retrieving data with the help of a cellular connection.

The electronics [Justin] chose for his remote wireless project include an AT&T 3G connection to the Internet provided by a Beaglebone, BeagleTouch display, and BeagleJuice battery pack. Of course an Arduino had to make it into this project, so a few light sensors were wired into a few Arduino Unos and connected to the Beaglebone.

After finding a few deep cycle boat batteries, [Justin] wired up a pair of solar panels that put out about 200 mA in full sun. This equates to about 2700 mAh a day, about 300 mAh more than his Beaglebone/Arduino/3G connection/WiFi setup needs per day.

As for what [Justin] can do with his wireless outpost, it makes setting up remote sensors for agriculture a breeze, and could easily be used to automagically send pictures from a game camera straight to a web page. Pretty neat, and very useful if you need to wire up sensors in the field to the Internet.

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Taking A Look At Decapped ICs

August 13, 2012 by Brian Benchoff 37 Comments

Aside from wanting to play around with nitric acid, [Ben] really didn’t have a reason to decap a few 74xx and 4000-series logic chips. Not that we mind, as he provides a great tutorial at looking at a bare IC that isn’t covered in epoxy and resin.

Most ICs are encased in a hard epoxy shell making it very difficult to look at the circuits within. [Ben] tried to grind this epoxy off with a Dremel tool, but didn’t have much luck until he moved over to a CNC mill to remove 0.040 – 0.050″ of epoxy without breaking the bond wires.

After carving out a nice pocket above the die, [Ben] put a few drops of nitric acid on the chip to dissolve the epoxy coating. This worked very slowly at room temperature, but after putting the chips on a hot plate the acid was able to reveal the die underneath.

After successfully removing all the epoxy and giving them an acetone bath, [Ben] took his chips over to the microscope and was able to check out the underlying circuit. He doesn’t have any idea what he could do with these decapped logic chips, but the bond wires are still intact so he could still use these chips in a build.

We’d like to see a few decapped MEMS devices, but if you have a suggestion on what [Ben] can do with his decapped chips, drop a note in the comments.

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Building A Casting Furnace With Heat Exchanger

August 13, 2012 by Mike Szczys 7 Comments

This completely DIY casting furnace turned out just great thanks to all the work [Biolit11] put into it along the way. He wanted to replace his older furnace with one that was more efficient, and to that end he built a heat exchanger into the design. This way the exhaust will preheat the intake air.

The furnace itself started with the shell of an old electric water heater. Excluding the design process, the majority of the build involved mold making. For circular parts he’s using quick tube, the paperboard forms used for pouring concrete footings. For more intricate parts he shaped polystyrene. They are layered in place and high-temperature cement is poured to form the permanent parts. After it hardens the polystyrene can be removed in chunks.

The heat exchanger is the part to the left. It includes several wide, flat pipes made of cement for removing the exhaust. Around those pipes a snaking metal chase carries the intake air which picks up the heat as it passes over the exhaust pipes.

For his first run with the new furnace he melted down a bunch of scrap aluminum and poured ingots.

[Thanks DC3]

The Coming Age Of ARM Chips For The Hobbyist

August 13, 2012 by Brian Benchoff 98 Comments

The days of the 8 bit Arduino may be quickly coming to a close. Sure, there will always be a place for AVRs in blinking LEDs and turning on relays, but for doing anything cool – playing MP3s, driving LCD displays, or running a CNC machine – you need the power of a 32 bit chip. [Brian Carrigan] put up a great tutorial on getting started with these bigger, more powerful micros and moving beyond what is possible with an 8 bit PIC or AVR.

These new 32 bit chips are much more powerful, but aren’t exactly hobbyist friendly. Most of the ARM chips we’ve found are stuffed into very fine pitch QFN or QFP packages that require a reflow oven to solder to a board. In fact, we can only find one through-hole Cortex M0 chip that is suited for breadboard development. This doesn’t make it easy to whip up a circuit in a few hours, so builders needing a very powerful microcontroller will be more dependent on dev boards.

Already there are a good number of ARM-based 32 bit dev boards available including the offerings from Leaf Labs, the extremely inexpensive STM Discovery board, Kinetis KL25Z Freedom Board, the outrageously powerful BeagleBone, and the perpetually delayed Arduino (over) Due.

None of these boards are particularly new developments; they’ve all been around the block once or twice. However, there are many more options for 32 bit development than the current 8 bit PIC and AVR holy war. We’re going to turn the comments over to Hackaday readers with the following questions: what supersized dev board are you rolling with? What’s good for a beginner, and what should they watch out for?

Writing Javascript Without Using Any Letters Or Numbers

August 13, 2012 by Mike Szczys 19 Comments

Did you know it’s possible to write Javascript code without using any letters or numbers at all? Well, it’s not just Javascript, but that’s the language used in this demonstration. [Patricio Palladino] shows how code can be written using just eight characters, and all of them are punctuation marks.

Typecasting is the name of the game here. By starting out with an empty array formed by a pair of square brackets, [Patricio] can generate the number zero by casting the array with the plus sign. From there he can use an exclamation point (a boolean cast) and addition to generate any number. The image above is an example of the digits 0-9. This would get very tedious for larger numbers but there’s another shortcut. Cast the digits to strings, concatenate them, then cast back to a number and you’re in business.

The technique is fascinating, and basically unreadable. As a proof of concept he wrote a parser that will convert any Javascript into this hieroglyphy. Check out his Github repository to give it a try.

[via Reddit]

Hackaday Links: August 12, 2012

August 12, 2012 by Mike Szczys 23 Comments

License plate tablet rack

[Hunter Davis] used an old license plate as a tablet stand. It loops around the leg of his laptop table and has a cutout for the power cord of the tablet.

More power power wheels