70 LED Matrix In A Jack-o-lantern

October 26, 2010 by Mike Szczys 23 Comments

What takes eight hours to solder and uses more shrink tubing that you thought imaginable? An LED matrix installed in a real pumpkin. When I mentioned that we’d like the LED pumpkin in last Friday’s post scaled up to a full LED matrix I had no idea it would be me doing the work. But [Caleb] and I thought it might be just the thing to present for the hacker’s favorite holiday.

Installed in the autumn vegetable is a marquee made from a 5×14 matrix of light emitting diodes. I spaced them by printing out a grid on the computer, taping it to the pumpkin, and drilling 70 holes in the front of the thing. The real trouble came when inserting all of the LEDs from the inside; each of them has four wires soldered to it, creating a net of black wiring. Above you can see it turned out great. This is a shot of it scrolling the message HAPPY HALLOWEEN.

Join us after the break for video of this prop. But we’re not just sharing the finished product. I’ll take you through the build process. Along the way you’ll learn the design considerations that go into an LED matrix and how you can use these techniques to build your own in any size and configuration you desire.

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RC Controlled Camera Takes Intimate Video Of Rodents

October 25, 2010 by Mike Szczys 27 Comments

[Leor] wanted to take some video of the wildlife in his yard, like this chipmunk or some hummingbirds, but every time he tried to get close it scared them away. His solution was to rig up a cheap video recorder to be radio controlled (PDF). The donor camera was a cheap SD card based eBay purchase that takes 720×480 video. [Leor] removed the SMD switches from the recorder’s PCB and wired up a 4066 quad bi-lateral switch IC in its place. An RC toy car donated the receiver transmitter pair. The receiver signals are monitored by an AVR microcontroller which translates the commands in a proper set of button presses for the video. What you get is a controller that and turn the camera on and set to the proper mode, and the ability to start and stop the recording.

We’ve got some pics of the hardware after the break, and [Leor] posted a bit of the chipmunk video for your enjoyment.

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AVR Programming 02: The Hardware

October 25, 2010 by Mike Szczys 67 Comments

You may be able to write the most eloquent code in the history of embedded systems but without a way to run it on the hardware it will be worthless. In this installment of the tutorial series we will:

Look at some of the available AVR programmer options
Place the microcontroller on a breadboard and connect it to a power supply and a programmer.
Use programming software to send some example code to the microcontroller

If you missed Part 1 take a few minutes to review that portion of the tutorial and then join us after the break.

Series roadmap:

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AVR Programming 01: Introduction

October 23, 2010 by Mike Szczys 69 Comments

We love looking at hardcore electronics projects with a beefy microcontroller and hundreds, if not thousands, of lines of code at its center. But everyone needs to get there somehow.

This tutorial series aims to make you comfortable programming the Atmel AVR line of microcontrollers. Whether you’ve never touched a microcontroller before, or you’ve cut your teeth with dozens of Arduino projects, this will help you get right down to the hardware and give you the confidence to build anything.

Series roadmap:

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AVR DDS Signal Generator Improvements

October 20, 2010 by Mike Szczys 11 Comments

[Vassilis Papanikolaou] took a good thing and made it better with some design upgrades to this AVR based signal generator. We looked at version 1.0 of this tool back in 2006 and since then it saw an upgrade to 2.0. But [Vassilis] wanted to take things one step further, with a compact single-sided PCB. What you see above is the beautiful result of his work; a professionally made board that is compact, uses through-hole components, and has zero wire jumpers.

If you want to build one for yourself there’s a great parts list as well as board artwork and schematic. The system uses an ATmega16 so you’ll need a way to program one. There’s also just a bit of firmware tweaking to remap the control buttons to match the updated hardware layout.

Window Curtain Moves To Screen Pedestrians

October 15, 2010 by Mike Szczys 24 Comments

[Niklas Roy] built a motorized window curtain to screen out foot traffic in front of his window. When you hear “motorized curtain” you may think that this will move up and down but it doesn’t. Instead, the small curtain move horizontally to cover passersby as they travel down the sidewalk. This is accomplished using a camera in conjunction with some motion sensing software. In the video after the break you can see that the software also anticipates the movement, and ends up doing a good job of keeping the target covered. That’s thanks to the Processing sketch working in conjunction with a rotary encoder on the hardware setup. Details for both are available on the page linked above.

This harkens to other community involvement hacks we’ve seen like the subway stair piano, or the bottle recycling video game. It’s fun and quirky, which is not too much of a surprise as we saw a glimpse of that when we looked at [Niklas’] public fountain hydropower generator.

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Lazarus-64, Not Actually 64 Bit But Still Blows Our Minds

September 29, 2010 by Jakob Griffith 16 Comments

Lazarus-64, breadboard game system; certainly sounds like something from the 1980s. We were surprised to find out not only the name, but also all the ICs used are only those available from the retro age of 30 years back (Save for the AVR controlling everything, of course). Even more amazing is how it has 256 flicker free color support, while not using NTSC chips. Which Goes to show that even if there are common solutions out there for cheap, building or compiling your own is not necessarily a bad thing or a waste of time.

There is a whole lot more to Lazarus, including double buffering and VMS, but sadly it appears progress has stopped on the Lazarus-64 breadboard game system, with the last update being last year. But we can still bask in the amazing glow that currently is.