Week 4 - Electronic Dice

This week, we were supposed to build a circuit that digitally simulates rolling a die. The last time I attempted this, I was able to get the thing working, but not correctly. It would show some numbers perfectly, but others (4, if I remember correctly) would display random LEDs. This time, I started out with that in mind. For my first step, I decided to find an online tutorial demonstrating how to achieve the desired results. I found several, including some that used an LED numerical display. Unfortunately, I don’t have that numeric display. So, I eliminated those immediately. Then, I settled on one that the maker seemed very confident about. As it turns out, that confidence was either unfounded, or the instructions presented were too confusing. So, I found another tutorial that seemed more put together, and actually had a schematic that I could work from. I bypassed nearly all the instructions and pictures, and focused almost entirely on the schematic. Built the circuit, downloaded and verified the code, uploaded said code to my Arduino and had an LED that wouldn’t light up. But, it was a simple matter of wire tracing. I quickly discovered that I had two leads running to 1 LED and none to the one at the opposite end of that string of LEDs. I moved that wire and, voila! It worked perfectly. The saying: “The more you do it, the easier it gets!” is true, especially in something like this.

The code I used for this (without comments) is below:

i nt pinLeds1 = 10;
int pinLeds2 = 9;
int pinLeds3 = 7;
int pinLed4 = 8;
int buttonPin = 6;
int buttonState;
long ran;
int time = 2000;

void setup ()
{
  pinMode (pinLeds1, OUTPUT);
  pinMode (pinLeds2, OUTPUT);
  pinMode (pinLeds3, OUTPUT);
  pinMode (pinLed4, OUTPUT);
  pinMode (buttonPin, INPUT);
  randomSeed(analogRead(0));
}

void loop()
{
  buttonState = digitalRead(buttonPin);
  if (buttonState == HIGH){
    ran = random(1, 7);
    if (ran == 1){
      digitalWrite (pinLed4, HIGH);
      delay (time);
    }
    if (ran == 2){
      digitalWrite (pinLeds1, HIGH);
      delay (time);
    }
    if (ran == 3){
      digitalWrite (pinLeds3, HIGH);
      digitalWrite (pinLed4, HIGH);
      delay (time);
    }
    if (ran == 4){
      digitalWrite (pinLeds1, HIGH);
      digitalWrite (pinLeds3, HIGH);
      delay (time);
    }
    if (ran == 5){
      digitalWrite (pinLeds1, HIGH);
      digitalWrite (pinLeds3, HIGH);
      digitalWrite (pinLed4, HIGH);
      delay (time);
   }
   if (ran == 6){
      digitalWrite (pinLeds1, HIGH);
      digitalWrite (pinLeds2, HIGH);
      digitalWrite (pinLeds3, HIGH);
      delay (time);
   }
  }
  digitalWrite (pinLeds1, LOW);
  digitalWrite (pinLeds2, LOW);
  digitalWrite (pinLeds3, LOW);
  digitalWrite (pinLed4, LOW);
}

The circuit, itself, can be seen in the photo below. I found that the 2 most difficult parts of this week were: 1) keeping the wires from pushing the LEDs out of alignment or covering them up, and 2) finding a tutorial or instructional for this circuit that actually worked and was easy enough to follow.

The schematic that I used to build the above circuit is found below.

And, here is the build in action.

This week’s build was, at first, a bit difficult to find in the real world. However, once I stopped thinking of purely physical aspects and considered digital applications, as well as those that use a numeric display, I realized that this is something that is used in many different areas with some modifications. For example, we play a game called Farkle. In the physical world, we use physical dice. However, we have recently discovered digital versions of the game which use various forms of digital dice. Also, our refrigerator uses a similar circuit and coding to display temperatures and other settings. The difference with the refrigerator is that it is not displaying random numbers (we hope), but uses data from sensors in the appliance to tell the numeric displays what areas to light up. I think there may be a way to use this challenge build with some modifications to display the speed on my “boosted board” project that I want to build.