Monday, April 12, 2010

Chapter 24 - Exercise 23 Complete

The photos here show the circuit on page 219 (Figure 4-109). I'm not sure if I'll go forward with the enhancement described on page 220... I understand what it does and how it works, but wiring up this one took a bit of time (and mega-patience) and I'm a bit ready to move forward.

I managed to purchase 10 of the 1N4148 diodes from Radio Shack - they ordered them and it cost me $1.49 for a pack of 10... and took about 10 days to get here... boo. (I was told 2-3 days... another valuable lesson learned... of course, I didn't have to pay for shipping which would have been more than the 10-pack!)

As you can from the video, the circuit works. I like when you hold and release the button -the visual effect is fun to watch. I may come back later after the book is done and see about wiring up a pair of dice as the author has done... could be fun.

I recommend reading over this entire exercise a few times... there is a LOT to sink in. I really like seeing how the author developed the logic of the dice face (LO LO HI, for example) and how he created the circuit to operate in a fairly simple manner... if you were to look at that big, full color patchwork on page 221, you might think this is an extremely complicated circuit... don't let all those wires fool you - all the hard work is being done by the chips.

All in all, a VERY cool experiment and one I enjoyed. I'm going to go back and re-read this entire chapter, because I've been collecting a small list of circuits I'd like to wire up and many of them are going to require chips... lots of chips. So, I want to make sure I have a 100% grasp on this stuff... you should, too.

If any of my readers wire up two dice or move forward with the enhancement, please send me a photo or video (both would be outstanding) and I'll be happy to post an addendum to this one with a few of the best examples.


  1. Congratulations James, I'm glad that it worked.

    I am going to have a column in Make on a regular basis, going farther into some of the topics mentioned in my book. The first instalment will use some of the knowledge gained in the electronic dice circuit to build an electronic version of the old "Whac-a-Mole" arcade game. I wanted to put this in the book, but I couldn't simplify the circuit sufficiently. Subsequently I found a way around this problem.

    The second column will show how the game can be enhanced by using a microcontroller instead of 5 of the chips. In both columns I will suggest many different directions that the reader may want to follow, fanning out from the topics raised by the game design.

  2. Glad to hear it - I've been wondering about what I'll do when Exercise 36 is completed. I don't want to just walk away from the blog, so these will be welcome content.

    I've been collecting some random electronics projects from the web here and there and am also considering just continuing to post random projects as I can.