The PC board version of the LED Dice was housed in a zippy box with the LEDs and switch emerging through the front panel. The red LEDs form one dice while the orange LEDs form the second (yes, we know we said we used green ones!).
First of all, let’s settle
an argument before it starts. Die or Dice? Sure, the venerable Oxford
would have us say one die, two dice. But every man and his dog uses the word
"dice" for both singular and plural. So we’ll stick with Fido and use dice.
But just in case you still want to argue, we’re correct either
way with this circuit because it contains not one but two dice. So it’s perfect
for all of those games which require the roll of two dice at once.
By the way, if you only want a single version, that’s easy too:
just leave out one set of LEDs and driver resistors. The PIC micro will never
Ahh, the PIC micro. We were getting to that. Using a PIC allows
us to significantly simplify our dice circuit. Previous designs have typically
used at least two ICs, four or more transistors and many resistors and
And they’ve been fairly current hungry, discharging batteries
far too quickly.
Using a single microcontroller not only allows simplification,
it also lets us add features that previously haven’t been available: the ability
to recall the last roll, for example.
The second version of the LED Dice is the same circuit but is built on Veroboard and this forms the lid of a zippy box. Some components are mounted on the other side of the board. Note that some component values have been altered.
This is the first in a short series of articles we hope to
publish over the next few months which will use PICs in a variety of simple
What makes this series a little different is that we intend to
guide you through the hardware and software design step-by-step so that you get
a better idea of the design process.
It’s an ideal way for a beginner in micros to get a grasp on
We are not planning to print detailed software descriptions,
though – magazine space simply does not allow this.
However, a web site has been set up to provide detailed
software discussions of all the projects presented in the series.
Before we start our design, let’s look at the basis for all of
these projects, the PIC microcontroller.