Modified a simle project from gcduino.com and made it a random dice with roll down feature.

Get a random value from pin A5 (note pin in mid air in photos) of Atmega and uses that as the an offset for the random number generator.

Here is the code

/*
* SevenSegment sketch with dice roll down and button press
* Shows numerals ranging from 1 through 6 on a single-digit display
*/

boolean numArray = {
// C,E,D,dp,B,F,G,A segments
{1,1,1,0,1,1,0,1},                       //Zero                      ===A(17)===
{1,0,0,0,1,0,0,0},                   //One                      |                  |
{0,1,1,0,1,0,1,1},                      //Two                   F(15)           B(14)
{1,0,1,0,1,0,1,1},                      //Three                    |                  |
{1,0,0,0,1,1,1,0},                     //Four                     ===G(16)===
{1,0,1,0,0,1,1,1},                      //Five                       |                  |
{1,1,1,0,0,1,1,1},                       //Six                      E(11)           C(10)
{1,0,0,0,1,0,0,1},                    //Seven                   |                  |
{1,1,1,0,1,1,1,1},                        //Eight                     ====D(12)==      DP-13
{1,0,1,0,1,1,1,1}                        //Nine
};

const int button = 8;                                               //set button to input 8
int randNummer = 0;

void setup(){
for(int i = 10; i <= 17; i++) {                                       //Setup the pins controlling the 7 segment display
pinMode(i, OUTPUT);
digitalWrite(i, HIGH);                                              //Turn all segments off
pinMode(button, INPUT);                                     //Set button as input
}
}

void loop()
{
boolean btnState = digitalRead(button);               // Read the state of the button, either 5v or 0v and store it in the variable btnState
if(btnState == LOW){                                                // if the button state is HIGH run the code between the "{}" brackets
randomSeed(analogRead(5));                               // used A5 as random offset for random generator
randNummer = random(1,7);                                  // Random number between 1 and 6 (7max-1)
digitalWrite(16, HIGH);                                            // Clear the middles segment
for(int w = 5; w < 12; w = w + 3){                            //This is the slow down loop
for(int a = 6; a >= 0; a--){                                        //Count down through the Numbers
for(int j = 0; j <= 6; j++){                                           //Loop through the d6 outer segment
int myArray={11,15,17,14,10,12};                             //sequence of segments for the roll display
delay(w);                                                                 //variable delay
digitalWrite((myArray[j]), LOW);                             //set segment on
delay(w);                                                                 //variable delay
digitalWrite((myArray[j]), HIGH);                            //set segment off
}
}
}
for(int j = 0; j <= 8; j++){                                          //Loop through the segments to make up number display
digitalWrite(j+10, !numArray[randNummer][j]);    //look up array for the random number
}
}
else {
digitalWrite(13,LOW);                                               //flash the dot on and off
delay(100);
digitalWrite(13,HIGH);
delay(100);
}
}