Category Archives: Microcontrollers

A simple persistence of vision approach to Lissajous figures

lissajous-dark - 07

Lissajous figures are interesting curves that occur in systems where oscillation happens in more than one direction, for example when a pendulum hanging from a string moves in its plane.

The “standard” way to play with Lissajous figures is on an oscilloscope, and the easy way is of course in a web app, but there is also something to be said for a demo that you can hold in your hands. In what follows, we build a simple apparatus that takes a persistence of vision approach to displaying Lissajous figures.
Continue reading A simple persistence of vision approach to Lissajous figures

20 millicenturies of Evil Mad Scientist Laboratories

Evil

Happy birthday to us! Evil Mad Scientist Laboratories is now two years of age. Collected below is a “Best of Evil Mad Scientist” for the past year: Some of our favorite projects that we’ve published over the last twelve months. Here’s to the next year!

Quick projects:

Set of bands
Rubberbands made from old bicycle innertubes.

vertical light tent setup
Light tent made from a lampshade.

Still life with yellow paper (group shot 2)
Chip bugs

Enterprise
Bristlebots

Sizing
Spool spinner from an old fan.

Quick C to D adapter
The $1.00 C to D adapter

Electronics projects

Weekend Projects Podcast!
How to make a Joule Thief from Make: Weekend Projects.

lights off?
How to make a dark-detecting LED night light.

The Great Internet Migratory Box Of Electronics Junk
The Great Internet Migratory Box of Electronic Junk

Finished 1
How to make a Sawed-off USB Key

AVR microcontroller projects

ADXL3XX
Using an ADXL330 accelerometer with an AVR microcontroller

Snapper - 09
Snap-o-lantern

Kit Projects

XX8_complete
AVR Target Boards

Four Panels 2
Interactive Table Kits

Resist1- Wall hanging
Peggy

grayscale
Peggy v 2.0

Crafty Projects

Q*bert close-up
QuiltBert

vintage software book handbag
Software Handbag

iPod inside
iPod cozy

Earrings 2
Fimo Fractals

Miniature Art Car
Mini Art Cars

New wing
Umbrella Bat Costume v 2.0

Food Hacking

cooking
Cooking hotdogs

555 LED flasher 1
Circuitry Snacks

Googly FSM
Edible Googly Eyes

Sierpinski Cookies-11
Fractal Cookies

CandyFab

Sugar Chain
Printing complex shapes: Sugar Chain

Before and after 2
Candyfab improvements: higher resolution and edible output

Papercraft:

Usage 3: First operand
Rotary Fraction Adding Machine

toner - 15
Electric Origami

Observations & silly projects:

Cat volume computation
Volume of a cat

Gourds
Pacman Halloween

Lego Projects:

Lego Shooter
Forbidden Lego review & build

Technic Bits
Efficient Lego Storage

Reviews:

suction tool
Obscure electronics tools

Lee Valley & Veritas catalog
Lee Valley & Veritas Catalog Review

Teardowns:

Twisted leads (close-up)
LED Stoplight

All the parts
pedometer
hp2600n - 178
HP Color LaserJet 2600n

Tiny portable AVR projects: Business card breakout boards

XX8_complete

For all of our different AVR microcontroller based projects, we seem to find ourselves continually wiring up minimalist target boards; little circuit boards that fit both the AVR and a 6-pin header for connecting to your in-system programmer. And, when you find yourself hand-wiring the same circuit over and over again on a protoboard, that’s really just life’s way of telling you “just lay out a damn printed circuit board already.”

Coincidentally, we needed a new business card.
Continue reading Tiny portable AVR projects: Business card breakout boards

Reminder: Microcontroller classes this week at TechShop

   ATtiny2313

Tomorrow (Monday 3/3/08) at TechShop in Menlo Park, CA, I’m giving another AVR intro class. These classes have been big, lively, engaging and interesting, with a lot of good questions– two sessions are scheduled this month:

Monday, 3/3/08, 6:30-8:30 PM, and

Saturday, 3/22/08, 1:00-3:00 PM

Seminar: Introduction to AVR Microcontrollers

AVR microcontrollers are powerful and versatile single-chip computers that cost only a few dollars each. You may have noticed that a number of our interesting projects are based around these, using them to make smart little toys and machines.

This class is aptly billed by TechShop as “How To Use AVR Microcontrollers in Your Projects.” Indeed. We’ll be bringing along a number of our cool AVR-based Evil Mad Scientist Laboratories projects from to show off some of the things that you can do with these little marvels, and how you might go about doing it.

Formal class description: “AVR microcontrollers are powerful, versatile and inexpensive single-chip computers that are remarkably easy to program in C, using entirely free and open-source tools that run on Macs, Windows, and Unix-like operating systems. In this practical introduction to AVR microcontrollers, we’ll take it from the beginning so that you can get started using them for your own cool projects. Some topics to be covered include: different types of AVRs and how to pick one for your application, getting a programmer, installing software tools, how to get started actually programming them, and how to download and run your code on the microcontroller. Class format is a one hour lecture followed by show-and-tell demonstrations and ample time for questions.”

Sign up here.
   

Seats are still available in one other microcontroller project class:

Soldering Project: Build a Micro Readerboard

A fun little soldering class, where you can customize the phrases in and build your very own LED Micro-Readerboard. It’s a cute little toy that spells out a preprogrammed messages (e.g., your name– for an LED nametag!), one letter at a time, on its display. In the class, you get to choose what messages to put on your readerboard, solder it together and take it home. It’s a neat, self-contained project that’s a great example of what you can do with a little AVR microcontroller; a perfect “my first microcontroller” project for anyone who hasn’t played with one yet. This is an intermediate soldering class; some prior soldering experience is needed. Other than that, no prior knowledge is assumed, so this class is great for kids too.

Next Classes:

  • Saturday, 3/8/08, 1:00 PM
  • Saturday, 3/22/08, 4:00 PM

Sign up here!

Learn about microcontrollers at TechShop in 2008

Starting next week and over the next few months, I’ll be teaching several different self-contained microcontroller-oriented classes at TechShop, at different levels of skill and with different emphases:

 

 

  • Soldering Project: Build a Micro Readerboard
  • Soldering Project: Build an AVR Programmer
  • Seminar: Introduction to AVR Microcontrollers

The classes are held at TechShop, a San Francisco Bay Area “open-access public workshop,” located just off of 101 in Menlo Park, where you can go use a wide range of tools to make things, and take all kinds of classes.
   

Soldering Project: Build a Micro Readerboard

This is a fun little soldering class, suitable for anyone with a bit of soldering experience (even youngsters), where you can customize the phrases in and build your very own LED Micro-Readerboard. It’s a cute little thing that spells out a preprogrammed messages (e.g., your name), one letter at a time, on a single-character alphanumeric display. In the class, you get to choose what messages to put on your readerboard, solder it together and take it home. It’s a neat, self-contained project that’s a great example of what you can do with a little AVR microcontroller. This is an intermediate soldering class; a little bit of prior soldering experience is assumed. The class typically runs about 90 minutes, but soldering experts will finish more quickly and we’ve reserved space for two hours just in case. Class size is limited to 5 students.

This class is scheduled to be given

  • Saturday, 2/9/08 1:00 PM
  • Saturday, 2/23/08 4:00 PM
  • Saturday, 3/8/08, 1:00 PM
  • Saturday, 3/22/08, 4:00 PM

Sign up here.

 

And speaking of AVR Microcontrollers….
Seminar: Introduction to AVR Microcontrollers

ATtiny2313AVR microcontrollers are powerful and versatile single-chip computers that cost only a few dollars each. You may have noticed that a number of our interesting projects are based around these, using them to make smart little toys and machines.

This class is aptly billed by TechShop as “How To Use AVR Microcontrollers in Your Projects.” Indeed. We’ll be bringing along a number of our cool AVR-based Evil Mad Scientist Laboratories projects from to show off some of the things that you can do with these little marvels, and how you might go about doing it.

Formal class description: “AVR microcontrollers are powerful, versatile and inexpensive single-chip computers that are remarkably easy to program in C, using entirely free and open-source tools that run on Macs, Windows, and Unix-like operating systems. In this practical introduction to AVR microcontrollers, we’ll take it from the beginning so that you can get started using them for your own cool projects. Some topics to be covered include: different types of AVRs and how to pick one for your application, getting a programmer, installing software tools, how to get started actually programming them, and how to download and run your code on the microcontroller. Class format is a one hour lecture followed by show-and-tell demonstrations and ample time for questions.”

This class is scheduled to be given

  • Tuesday, 2/5/08 6:30-8:30 PM
  • Saturday, 2/23/08 1:00-3:00 PM
  • Monday, 3/3/08, 6:30-8:30 PM
  • Saturday, 3/22/08, 1:00-3:00 PM

And speaking of programming….

 

Soldering Project: Build an AVR Programmer

USBtinyISP, assembledIn this class you will solder together, test out and get to take home a USB programmer for AVR microcontrollers. With this hardware tool and free cross-platform software, you can use your computer to write code for and program these little one-chip wonders.

This is an Intermediate Soldering Project; you must have prior soldering experience. You are encouraged, but not required, to bring a laptop along. (If you do bring your computer, you should have a chance to install the necessary software and test it out with your new programmer.)

Class size is limited to 5 students.

This class is scheduled to be given

  • Saturday, 2/9/08 4:00-6:00 PM [Full!]
  • Sunday, 2/24/08 2:00-4:00 PM — Just added!
  • Saturday, 3/8/08, 4:00-6:00 PM [Full!]

Sign up for these and other TechShop classes here.

LED Mini Menorahs:: Open source kits

Holiday motivation

All cynicism aside, one of the cool things about the holiday season is that it often provides a good excuse to play with lights.

Hanukkah in particular has been a festival of lights for more than a dozen centuries longer than there have been lights on Christmas trees. History notwithstanding, Hanukkah still lags behind Christmas in the transition from traditional light sources like candles towards microcontroller driven arrays of LEDs. While that may be simply due to the relative flammability of dry pine trees versus that of metal menorahs, the irony is that Hanukkah– unlike Christmas– actually requires observers to light up specific lights in a specific order, which is exactly the sort of thing that you want a microcontroller for.

Can’t find an open-source LED menorah at your local big box store? Not to worry!
Make one yourself from our instructions, which include source code for the AVR microcontroller (we use an ATtiny2313). Complete soldering kits to make your own– no programming needed– are also now available in quantity at our new web store.
(Note: While I cringe every time that I see Christmas displays up before Halloween, we aren’t actually too early in this case. Hanukkah starts on the evening of December 4th this year.)

Make a Robotic Snap-O-Lantern!

Snapper - 02.jpg

Snapper - 06.jpg Snapper - 07.jpg Snapper - 09.jpg Snapper - 06.jpg

The Snap-O-Lantern is a robotic mini-pumpkin. Normally, it just sits there, in disguise as a boring old pumpkin. But, every twenty seconds he comes to life. His LED eyes turn on, his jaw slowly opens, and then SNAPS shut– and he goes back into stealth mode.

What’s inside? A small hobby servo motor, driven by an AVR microcontroller. This is a minimal microcontroller project, and is very straightforward if you happen to already have a setup for programming one. We’ll walk through the carving, setup, programming, and electronics. This is an open-source project, one of the world’s first “gpl-o-lanterns”; source code is provided.

Continue reading Make a Robotic Snap-O-Lantern!

Matt’s awesome chip desk

What does one do 434 discarded Itanium CPUs? Matt Tovey was inspired by our Chip Trivet, and used them to make this awesome computer desk.

   

The CPU modules were scrapped as the result of a supercomputer upgrade, and were presumably functional before having their heat sinks taken off– a herculean effort for that many CPUs! Matt says that the list price for the lot of chips was over US$800,000 in 2006 and that the desk contains about 2.8 TFLOPs of computing power, about the same
as 900 3.2GHz P4s.

Matt started with a plain desk, tiled in the CPUs, and added wooden edging and a beveled glass top. Nice work!

I just love the way that this desk looks. But it gives me an idea too– take it one step further, and what if it worked? You could use a single, giant PCB for the motherboard which sat underneath the glass surface of the desk. With that much area, you could fit in a lot of processing power. On the cheap (or moderately cheap), one could imagine instead filling the inside of a desk top with low-cost (even last-generation) PC motherboards to make a great looking beowulf cluster or render farm that doesn’t take up any desktop or rack-mount space.

Sadly, Matt’s page has moved on to the great /dev/null in the sky, but the mirror still shows some of the build photos.

Using an ADXL330 accelerometer with an AVR microcontroller

ADXL3XX   Makeshift socketX up: Red   X down: blue

The last decade has seen more than an order of magnitude drop in the price of
accelerometers, devices capable of measuring physical acceleration (often in more than one direction). History suggests that whenever a useful technology makes a precipitous drop in price, unexpected applications follow, and that’s exactly what has happened in this case.

Starting from zero and summing up acceleration, you can use an accelerometer to find velocity, and from that derive relative position information. By measuring the acceleration due to gravity, one can also determine orientation (technically, inclination)– you can tell which way it’s pointing. Those are pretty useful skills for a chip! And so as bulk prices for tiny chip-scale three-axis accelerometers have begun to approach $5, they have started to appear in all kinds of mass-market applications that you might not have predicted: laptop computers (for hard drive protection), smart phones and cameras (for orientation– e.g., portrait vs. landscape on the iPhone), cameras for image stabilization, and quite visibly in the controllers for Nintendo’s Wii system.

With all that promise, you might think that an accelerometer is a difficult beast to harness. That turns out not to be the case. In this little project we demystify the mighty accelerometer and show you how to get started playing with one. In the spirit of hobbyist electronics we do this the easy way– without designing a PCB or even soldering any surface-mount components.

Note: An updated version of this article is now available here.
Continue reading Using an ADXL330 accelerometer with an AVR microcontroller