Category Archives: Engineering

Geek Books!

Snip, Burn, Solder, Shred

We recently received review copies of four relatively new books from No Starch Press. Snip, Burn, Solder, Shred is a collection of technically oriented how-to projects covering a lot of the same ground that we cover in our projects here; sewing projects, music projects, electronics projects and others.

Lego Idea Book

The other three books are Lego Technic Idea Books: Fantastic Contraptions, Simple Machines, and Wheeled Wonders. And these are a phenomenal collection of assemblies and subassemblies providing the kind of masterful insight into Lego construction that comes from many years of careful study.

Snip, Burn, Solder, Shred

Snip, Burn, Solder, Shred by David Erik Nelson is largely descriptive, with diagrams and pictures sprinkled throughout. It covers an amazing range of activities and skills, including sewing, glueing, woodworking and soldering. There’s even a nice how to solder section.

Snip, Burn, Solder, Shred

Interestingly, none of the electronics projects requires programming. Shred refers to music, as many of the electronics projects are audio based. Many of the non-electronics projects are also musically inclined, but there is plenty for everyone in this book, from boomerangs to rockets.

Snip, Burn, Solder, Shred is a good introduction to making stuff, and is clearly oriented toward doing things with kids. It would be nice if it had full-color photography. Some of the projects have supplemental material which is worth checking out on the Snip Burn Solder Blog.

Lego Idea Book

The Lego books, by Yoshihito Isogawa are slim and nearly wordless. The main exposition happens in the table of contents, where the symbols that head each section are described.

Lego Idea Book

The body of the books unfold with beautiful full-color photography. The contraptions are cleverly constructed of different colors to make the mechanisms and assembly clear.

Lego Idea Book

Many of the assemblies seem obvious in retrospect, but the thought that went into them is deep and clear.

Lego Idea Book

Not all of the assemblies are obvious at first glance, and many are quite complicated, like this gear reduction assembly that allows two speeds in addition to direct gearing. For anyone who loves Lego, prototypes in Lego, or loves mechanical assemblies, these books are definitely required viewing, and we’re not sure how we lived without them for so long.

(Full disclosure: we received these review copies from No Starch Press, and Evil Mad Science is mentioned favorably as a resource in Snip, Burn, Solder, Shred as a resource. That could have influenced our opinion. Also, we like Legos.)

Hershey Text: An Inkscape extension for engraving fonts

header-fonts2

Hershey Text is an Inkscape extension that can render a line of text in one of several stroke-based “engraving” fonts. This extension solves a persistent problem, and one which we have come across in many different contexts: How to easily create simple and readable vector representations of text.

Quick start: Download and install the EggBot extensions for Inkscape, which now include Hershey Text. Much more information follows.

Continue reading Hershey Text: An Inkscape extension for engraving fonts

The 4313 has landed.

ATtiny4313-PU

One of our all-time favorite chips is the ATtiny2313.

It’s a little 20-pin AVR microcontroller that we’ve used in dozens of projects, including our high tech holiday decorations, some of our coolest pumpkins, our (digital) Larson Scanner, and some wacky papercraft— to name a few. It’s one of those few chips that we used often enough to justify a custom breakout board.

But… if there’s one thing that the ‘2313 is short on, it’s memory. With 2 kB of flash (program) memory and 128 bytes of RAM, it’s perfect for tiny single-purpose projects. But, it’s oh-so-easy to run up against that memory limit. And, that’s why we were so excited when Atmel began to announce their then-forthcoming ATtiny4313 in late 2009.

Unfortunately, it’s often a long delay between when a chip is announced and when it’s actually available through distribution. Sample quantities have been floating around for half a year or so, but– and finally— a big box showed up in the mail, and so here they are.

4313 - 3

Now, programming it. There are very few changes between the ‘2313 and ‘4313. Mainly, it’s what you’d expect: memory sizes (Flash, SRAM, EEPROM are all doubled), and the device signature is different.

Recent versions of AVR-GCC already support the ‘4313, and so it’s relatively straightforward to recompile an existing program (say, the Larson scanner firmware) to run on the ‘4313. There are some minor inconsistencies between the “io.h” header files for the two chips, and those inconsistencies can cause compiling to fail. For example, the register name “WDTCSR” (for watchdog control register) works on the ‘2313, but the ‘4313 io.h file lists that same register name as “WDTCR.” So, if you run into a place where AVR-GCC is confused after switching chips, you might be able to solve the issue by comparing that register name in the “io.h” files for the two chips.

Now, for programming the chip with avrdude, things are slightly more complicated. Avrdude does not yet natively support the ‘4313, but fortunately, you can add the new chip definition by editing the avrdude.conf file on your system. (On my Mac, where I use Crosspack as the AVR toolchain, I found that file at /usr/local/CrossPack-AVR/etc/avrdude.conf ) The ‘4313 code block can be added right below the ‘2313 code block, and you can download that code block here (via this mailing list post). So, a couple of steps, but works like a charm.

There aren’t a whole lot of these to go around right now, but we’ve put some of our ‘4313 chips into little dev kits that you can pick up at our store. Let’s see how long they last. ;)

Make Live

Becky and Matt

We’re looking forward to today’s premier of Make: Live, a new live web show hosted by Becky Stern and Matt Richardson. The show will feature show and tell DIY projects from guest makers and hackers– and we’ll hope to be amongst those guests in an episode later this year.

The first episode is Arduino focused, and features two (more) remarkable friends of ours: Steve Hoefer (of rock-paper-scissor-golve fame) and Collin Cunningham (of Make Video fame). Steve is bringing his Secret Knock Gumball Machine, and Collin will be discussing his MidiVox shield for Arduino.


The show runs live Wednesday January 26th, 9 PM Eastern / 6 PM Pacific, and you can see it at makezine.com/live or on UStream.

(And, if you can’t catch it live, they’ll be archiving it on their YouTube channel and iTunes podcast. We’ll post direct links to those when they’re available.)

Update: You can subscribe to the MAKE Podcast in iTunes, download Make: Live episode 01 in its entirety (m4v), or watch clips on YouTube.

The next episode, “Make: Live 02 – The Soldering Episode,” runs
Wednesday February 9th, at 9 PM Eastern / 6 PM Pacific

AVR Basics: Reading (and writing) flash contents

Programming on a target board

From our forums comes this interesting question:

   “Is it possible to download the contents of an ATmega168/328, essentially backing it up so that it can somehow be restored later?

For example: Let’s say I have lost the source code to a very useful program currently residing on a 328, but I need to flash it with a different sketch temporarily, then restore that original sketch. This would be useful in the case that the chip was soldered directly onto a board – a big mess to try to replace.
Is this possible in some way, perhaps by altering an ISP programmer?”

The answer is that yes indeed, it is possible– with a couple of exceptions that are worth mentioning. And on occasion, it’s even very useful. Continue reading AVR Basics: Reading (and writing) flash contents

A pumpkin that sleeps like a Mac

sequence - 06   sequence - 02sequence - 10   sequence - 16

Here’s an neat idea for a jack-o’-lantern: Hide a single white LED just beneath the thin surface of the pumpkin. And program it with the same slow “breathing” effect that indicates sleep on Mac computers.

The result? A pumpkin that sleeps like a Mac. It’s actually quite striking, in part because the effect becomes invisible every few seconds. It’s also an easy microcontroller project: our demonstration video and build instructions follow. Continue reading A pumpkin that sleeps like a Mac

Maker Faire and Eggbot on Martha Stewart Show

Egg-Bot

 

If you happen to be into TV and/or Eggbot, you might want to tune into the Martha Stewart Show on Wednesday, Oct. 20. Our collaborator, Bruce Shapiro, inventor of the Eggbot, will be on as a part of a special episode about Maker Faire which will show off some of the cool things that Martha and her colleagues discovered at Maker Faire New York. After the show is broadcast, you should be able to find photos and video from the episode here.

 

Photo by Scott Beale / Laughing Squid under cc-by-nc-nd license.

The Expandable Larson Scanner!

Three Units

“The Larson Scanner rocks, but it’s too short!”

“How can we expand the Larson Scanner?”

“Can you link multiple Larson Scanners together?”

These are just some of the questions that I have asked about the Larson Scanner.
And now, there’s an answer, in my first guest blog post here on Evil Mad Scientist Laboratories!

Continue reading The Expandable Larson Scanner!

Printing on a strangely shaped egg

egg1

egg2

egg3

One of those questions that keeps coming up about the Egg-Bot is, “Does the surface have to be perfectly smooth?” Or sometimes just, “Can you print on a golf ball?”

While we wouldn’t go so far as to say that you’ll have good luck printing on a tennis ball, it turns out that the surface doesn’t exactly have to be flat either. Golf balls certainly aren’t a challenge. And, as you can see above, you can even plot on strangely shaped “eggs,” so long as the surface is smooth enough that you can drag a marker along. Neat.

Update: We’ve posted some tips on using the Eggbot with pumpkins here.


You can find more pumpkin projects in our Halloween Project Archive.