Apple II Weather Display (part 1)

April 18, 2011 by Kevin Dady 24 Comments

Due to computer issues I had to rob some parts from my “electronics” computer, which wasn’t bad, since I was not working on anything at the time and I felt a software project itch. I also wanted to do something with my Apple //c, which resides on my computer desk, so this ghetto brute force “solution” to use the 25 year old computer as a weather display came about.

In a nutshell there is the Apple II, a serial cable, and a PC running linux mint 10 and a handful of command line utilities. My specific Apple is the fist revision of the //c which means its got a buggy rom and the serial port(s) can be troublesome, the best speed I was able to get was 600 baud with just basic, though every other model could probably go a little faster.

On the linux side, wget downloads html and the radar image from Weather Underground’s mobile site, which is not a perfect source, but its easy. A lua script phrases text and graphics into string patterns that the Apple II can handle as keyboard input, and its sent down a serial cable where it is drawn on screen in basic.

Yea its pretty darn slow … it typically takes about eight to twelve minutes to redraw the screen, which is not all that horrid (imo) considering what is going on, but anyone with a more serious take on this could find numerous ways to optimize it, I just wanted to see what it would look like.

Join us after the break for a short video and to read all the details about how this all works!

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How To Build A Ping-pong Ball Display

January 31, 2011 by Mike Szczys 41 Comments

If you’ve been lusting after your own glowing display we’re here to help by sharing some simple building techniques that will result in an interesting project like the one you see above. This is a super-accurate clock That uses ping-pong balls as diffusers for LEDs, but with a little know-how you can turn this into a full marquee display. Join me after break where I’ll share the details of the project and give you everything you need to know to build your own.

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Intro To Circuit Bending

January 11, 2011 by Joseph Thibodeau 54 Comments

Electronic musical instruments are a lot of fun for a hacker because, with a small palette of tools, know-how and curiosity, they are easily modified. As with any hack, there is always the chance that the subject will be ruined, so it’s not necessarily worth the risk to muck about inside your thousand-dollar pro synthesizer. Luckily for all of us, there are shovel-fulls of old electronic musical toys littering the curbs and second-hand shops of the world. These fun little devices provide ample opportunity to get familiar with audio electronics and circuit bending techniques.

A note on definitions: the term “circuit bending” can be synonymous with “hardware hacking” in the world of audio electronics, and we have seen some debate as to which term is better suited to a given project. We welcome you to share your viewpoints in the comments.

Keep reading to get started.
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AVR Programming 04: Writing Code, Etc.

November 19, 2010 by Mike Szczys 24 Comments

Welcome back to this fourth and final installment of the series. The first three parts should have been enough to get you off the ground, but a few more learning examples wouldn’t hurt. It’s also a good time to discuss some of the other things these little chips can do. Join me after the break to:

Expand the sample code, adding features to our simple program while I challenge you to write the code yourself.
Discuss AVR fuse bits, how to use them, and what to watch out for
Touch on some of the peripherals you’ll come across in these chips

As a grand flourish to the series, I’ve used the example hardware from this final part to build a bicycle tail light. Hopefully this will inspire you to create something much more clever.

Series roadmap:

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AVR Programming 03: Reading And Compiling Code

November 5, 2010 by Mike Szczys 41 Comments

In the last installment of our tutorial series we built a simple circuit on a breadboard and programmed an ATmega168 to make it run. That proves that you know how to follow directions, but the eureka moments of doing everything yourself are on the way. This time around you will get down and dirty with the datasheet, learning where each line of the sample code came from, and give your recently installed compiler a test drive. We will:

Talk about bitwise operators and how they work when coding for microcontrollers
Discuss C code shorthand
Review the sample code from Part 2 and talk about what each line of code does
Learn to compile code

If this is the first you’ve heard about our AVR Programming series, head back to Part 1 and start from the beginning. Otherwise, take a deep breath and we’ll being after the break.

Series roadmap:

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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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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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