Step 1: Setting Up the Bread Boards

Connect the bread boards by whatever means, we had to use hot glue to hold the two smaller bread boards to the larger one. Put the LEDs in the bread boards forming a 3 x 3 square with one of each colored LED in each segment of the square.

Step 2: Wiring

Place each of the resistors after the LED in their circuit. Run wires from the player controlled switches to the LEDs that you want the player to be controlling. Run wires from the same place as in the previous step and hook them up to the Arduino. Run wires from the opposite side of the switches to the positive strip on either the right or left side of the bread board. Run wires from the LEDs to the negative strips nearest them so that they all circulate into one strip then run one wire from the combined strip to the ground (gnd) on the Arduino. Run wires from the computer controlled lights to the Digital and Analog inputs on the Arduino board. Try and keep all the wires as low as possible or the second picture above may be how this turns out for you.

Step 3: Code

int computerArray[10] = {2,3,4,5,6,7,8,9,10};
typedef enum{
OPEN,
CLOSED_C,
CLOSED_P
}
BoxState;
int turn = 0;
int switchArray[10]={
11,12,13,14,15,16,17,18,19};
int switchArray2[10]={
2,3,4,5,6,7,8,9,10};
void setup(){

int i;
int e;
Serial.begin(9600);

randomSeed(analogRead(0));

for(i=0; i<9; i+=1){
pinMode(switchArray[i], INPUT);
}
for(e=0; e<9; e+=1){
pinMode(switchArray2[e], OUTPUT);
}
}
BoxState box1 = OPEN;
BoxState box2 = OPEN;
BoxState box3 = OPEN;
BoxState box4 = OPEN;
BoxState box5 = OPEN;
BoxState box6 = OPEN;
BoxState box7 = OPEN;
BoxState box8 = OPEN;
BoxState box9 = OPEN;

int game = 1;
int Array1[9] = {13,19,16,13,12,11,13,11};
int Array2[9] = {12,14,17,19,14,15,14,14};
int Array3[9] = {11,15,18,16,17,18,18,16};
void checkGame(){
int q;
for(q=0; q<8; q+=1){
if(digitalRead(Array1[q]) == HIGH && digitalRead(Array2[q]) && digitalRead(Array3[q])){
game = 2;
}
}
}
void checkComputerWin(){
if (turn%2 == 1){
if(box1 == CLOSED_C && box2 == CLOSED_C && box3 == OPEN){
box3 = CLOSED_C;
digitalWrite(7,HIGH);
game = 0;
turn+=1;
}
else if(box1 == CLOSED_C && box3 == CLOSED_C && box2 == OPEN){
box2 = CLOSED_C;
digitalWrite(8,HIGH);
game = 0;
turn+=1;
}
else if(box3 == CLOSED_C && box2 == CLOSED_C && box1 == OPEN){
box1 = CLOSED_C;
digitalWrite(9,HIGH);
game = 0;
turn+=1;
}
else if(box4 == CLOSED_C && box5 == CLOSED_C && box6 == OPEN){
box6 = CLOSED_C;
digitalWrite(4,HIGH);
game = 0;
turn+=1;
}
else if(box5 == CLOSED_C && box6 == CLOSED_C && box4 == OPEN){
box4 = CLOSED_C;
digitalWrite(6,HIGH);
game = 0;
turn+=1;
}
else if(box4 == CLOSED_C && box6 == CLOSED_C && box5 == OPEN){
box5 = CLOSED_C;
digitalWrite(5,HIGH);
game = 0;
turn+=1;
}
else if(box7 == CLOSED_C && box8 == CLOSED_C && box9 == OPEN){
box9 = CLOSED_C;
digitalWrite(10,HIGH);
game = 0;
turn+=1;
}
else if(box8 == CLOSED_C && box9 == CLOSED_C && box7 == OPEN){
box7 = CLOSED_C;
digitalWrite(3,HIGH);
game = 0;
turn+=1;
}
else if(box7 == CLOSED_C && box9 == CLOSED_C && box8 == OPEN){
box8 = CLOSED_C;
digitalWrite(2,HIGH);
game = 0;
turn+=1;
}
else if(box1 == CLOSED_C && box4 == CLOSED_C && box7 == OPEN){
box7 = CLOSED_C;
digitalWrite(3,HIGH);
game = 0;
turn+=1;
}
else if(box1 == CLOSED_C && box7 == CLOSED_C && box4 == OPEN){
box4 = CLOSED_C;
digitalWrite(6,HIGH);
game = 0;
turn+=1;
}
else if(box4 == CLOSED_C && box7 == CLOSED_C && box1 == OPEN){
box1 = CLOSED_C;
digitalWrite(9,HIGH);
game = 0;
turn+=1;
}
else if(box5 == CLOSED_C && box2 == CLOSED_C && box8 == OPEN){
box8 = CLOSED_C;
digitalWrite(2,HIGH);
game = 0;
turn+=1;
}
else if(box8 == CLOSED_C && box2 == CLOSED_C && box5 == OPEN){
box5 = CLOSED_C;
digitalWrite(5,HIGH);
game = 0;
turn+=1;
}
else if(box5 == CLOSED_C && box8 == CLOSED_C && box2 == OPEN){
box2 = CLOSED_C;
digitalWrite(8,HIGH);
game = 0;
turn+=1;
}
else if(box3 == CLOSED_C && box6 == CLOSED_C && box9 == OPEN){
box9 = CLOSED_C;
digitalWrite(10,HIGH);
game = 0;
turn+=1;
}
else if(box6 == CLOSED_C && box9 == CLOSED_C && box3 == OPEN){
box3 = CLOSED_C;
digitalWrite(7,HIGH);
game = 0;
turn+=1;
}
else if(box3 == CLOSED_C && box9 == CLOSED_C && box6 == OPEN){
box6 = CLOSED_C;
digitalWrite(4,HIGH);
game = 0;
turn+=1;
}
else if(box1 == CLOSED_C && box5 == CLOSED_C && box9 == OPEN){
box9 = CLOSED_C;
digitalWrite(10,HIGH);
game = 0;
turn+=1;
}
else if(box5 == CLOSED_C && box9 == CLOSED_C && box1 == OPEN){
box1 = CLOSED_C;
digitalWrite(9,HIGH);
game = 0;
turn+=1;
}
else if(box9 == CLOSED_C && box1 == CLOSED_C && box5 == OPEN){
box5 = CLOSED_C;
digitalWrite(5,HIGH);
game = 0;
turn+=1;
}
else if(box3 == CLOSED_C && box5 == CLOSED_C && box7 == OPEN){
box7 = CLOSED_C;
digitalWrite(3,HIGH);
game = 0;
turn+=1;
}
else if(box7 == CLOSED_C && box5 == CLOSED_C && box3 == OPEN){
box3 = CLOSED_C;
digitalWrite(7,HIGH);
game = 0;
turn+=1;
}
else if(box3 == CLOSED_C && box7 == CLOSED_C && box5 == OPEN){
box5 = CLOSED_C;
digitalWrite(5,HIGH);
game = 0;
turn+=1;
}
}
}
void checkPlayerWin(){
if(box1 == CLOSED_P && box2 == CLOSED_P && box3 == OPEN && turn%2 == 1){
box3 = CLOSED_C;
digitalWrite(7,HIGH);
turn+=1;
}
if(box1 == CLOSED_P && box3 == CLOSED_P && box2 == OPEN && turn%2 == 1){
box2 = CLOSED_C;
digitalWrite(8,HIGH);
turn+=1;
}
if(box3 == CLOSED_P && box2 == CLOSED_P && box1 == OPEN && turn%2 == 1){
box1 = CLOSED_C;
digitalWrite(9,HIGH);
turn+=1;
}
if(box4 == CLOSED_P && box5 == CLOSED_P && box6 == OPEN && turn%2 == 1){
box6 = CLOSED_C;
digitalWrite(4,HIGH);
turn+=1;
}
if(box5 == CLOSED_P && box6 == CLOSED_P && box4 == OPEN && turn%2 == 1){
box4 = CLOSED_C;
digitalWrite(6,HIGH);
turn+=1;
}
if(box4 == CLOSED_P && box6 == CLOSED_P && box5 == OPEN && turn%2 == 1){
box5 = CLOSED_C;
digitalWrite(5,HIGH);
turn+=1;
}
if(box7 == CLOSED_P && box8 == CLOSED_P && box9 == OPEN && turn%2 == 1){
box9 = CLOSED_C;
digitalWrite(10,HIGH);
turn+=1;
}
if(box8 == CLOSED_P && box9 == CLOSED_P && box7 == OPEN && turn%2 == 1){
box7 = CLOSED_C;
digitalWrite(3,HIGH);
turn+=1;
}
if(box7 == CLOSED_P && box9 == CLOSED_P && box8 == OPEN && turn%2 == 1){
box8 = CLOSED_C;
digitalWrite(2,HIGH);
turn+=1;
}
if(box1 == CLOSED_P && box4 == CLOSED_P && box7 == OPEN && turn%2 == 1){
box7 = CLOSED_C;
digitalWrite(3,HIGH);
turn+=1;
}
if(box1 == CLOSED_P && box7 == CLOSED_P && box4 == OPEN && turn%2 == 1){
box4 = CLOSED_C;
digitalWrite(6,HIGH);
turn+=1;
}
if(box4 == CLOSED_P && box7 == CLOSED_P && box1 == OPEN && turn%2 == 1){
box1 = CLOSED_C;
digitalWrite(9,HIGH);
turn+=1;
}
if(box5 == CLOSED_P && box2 == CLOSED_P && box8 == OPEN && turn%2 == 1){
box8 = CLOSED_C;
digitalWrite(2,HIGH);
turn+=1;
}
if(box8 == CLOSED_P && box2 == CLOSED_P && box4 == OPEN && turn%2 == 1){
box5 = CLOSED_C;
digitalWrite(5,HIGH);
turn+=1;
}
if(box5 == CLOSED_P && box8 == CLOSED_P && box2 == OPEN && turn%2 == 1){
box2 = CLOSED_C;
digitalWrite(8,HIGH);
turn+=1;
}
if(box3 == CLOSED_P && box6 == CLOSED_P && box9 == OPEN && turn%2 == 1){
box9 = CLOSED_C;
digitalWrite(10,HIGH);
turn+=1;
}
if(box6 == CLOSED_P && box9 == CLOSED_P && box3 == OPEN && turn%2 == 1){
box3 = CLOSED_C;
digitalWrite(7,HIGH);
turn+=1;
}
if(box3 == CLOSED_P && box9 == CLOSED_P && box6 == OPEN && turn%2 == 1){
box6 = CLOSED_C;
digitalWrite(4,HIGH);
turn+=1;
}
if(box1 == CLOSED_P && box5 == CLOSED_P && box9 == OPEN && turn%2 == 1){
box9 = CLOSED_C;
digitalWrite(10,HIGH);
turn+=1;
}
if(box5 == CLOSED_P && box9 == CLOSED_P && box1 == OPEN && turn%2 == 1){
box1 = CLOSED_C;
digitalWrite(9,HIGH);
turn+=1;
}
if(box9 == CLOSED_P && box1 == CLOSED_P && box5 == OPEN && turn%2 == 1){
box5 = CLOSED_C;
digitalWrite(5,HIGH);
turn+=1;
}
if(box3 == CLOSED_P && box5 == CLOSED_P && box7 == OPEN && turn%2 == 1){
box7 = CLOSED_C;
digitalWrite(3,HIGH);
turn+=1;
}
if(box7 == CLOSED_P && box5 == CLOSED_P && box3 == OPEN && turn%2 == 1){
box3 = CLOSED_C;
digitalWrite(7,HIGH);
turn+=1;
}
if(box3 == CLOSED_P && box7 == CLOSED_P && box5 == OPEN && turn%2 == 1){
box5 = CLOSED_C;
digitalWrite(5,HIGH);
turn+=1;
}

}

void playRandom(){
int ran = random(0,90);
if(ran <= 10 && box1 == OPEN && turn%2 == 1){
box1 = CLOSED_C;
turn+=1;
digitalWrite(9,HIGH);
}
if(ran <= 20 && ran > 10 && box2 == OPEN && turn%2 == 1){
box2 = CLOSED_C;
turn+=1;
digitalWrite(8,HIGH);
}
if(ran <= 30 && ran > 20 && box3 == OPEN && turn%2 == 1){
box3 = CLOSED_C;
turn+=1;
digitalWrite(7,HIGH);
}
if(ran <= 40 && ran > 30 && box4 == OPEN && turn%2 == 1){
box4 = CLOSED_C;
turn+=1;
digitalWrite(6,HIGH);
}
if(ran <= 50 && ran > 40 && box5 == OPEN && turn%2 == 1){
box5 = CLOSED_C;
turn+=1;
digitalWrite(5,HIGH);
}
if(ran <= 60 && ran > 50 && box6 == OPEN && turn%2 == 1){
box6 = CLOSED_C;
turn+=1;
digitalWrite(4,HIGH);
}
if(ran <= 70 && ran > 60 && box7 == OPEN && turn%2 == 1){
box7 = CLOSED_C;
turn+=1;
digitalWrite(3,HIGH);
}
if(ran <= 80 && ran > 70 && box8 == OPEN && turn%2 == 1){
box8 = CLOSED_C;
turn+=1;
digitalWrite(2,HIGH);
}
if(ran <= 90 && ran > 80 && box9 == OPEN && turn%2 == 1){
box9 = CLOSED_C;
turn+=1;
digitalWrite(10,HIGH);
}
}

void loop(){
if(turn%2 == 0){
if(digitalRead(19)== HIGH && box4 == OPEN){
box4 = CLOSED_P;
turn+=1;
}
if(digitalRead(11)==HIGH && box3 == OPEN){
box3 = CLOSED_P;
turn+=1;
}
if(digitalRead(12)==HIGH && box2 == OPEN){
box2 = CLOSED_P;
turn+=1;
}
if(digitalRead(13)== HIGH && box1 == OPEN){
box1 = CLOSED_P;
turn+=1;
}
if(digitalRead(14)== HIGH && box5 == OPEN){
box5 = CLOSED_P;
turn+=1;
}
if(digitalRead(15)== HIGH && box6 == OPEN){
box6 = CLOSED_P;
turn+=1;
}
if(digitalRead(16)== HIGH && box7 == OPEN){
box7 = CLOSED_P;
turn+=1;
}
if(digitalRead(17)== HIGH && box8 == OPEN){
box8 = CLOSED_P;
turn+=1;
}
if(digitalRead(18)== HIGH && box9 == OPEN){
box9 = CLOSED_P;
turn+=1;
}

}
if(turn%2 == 1){
checkComputerWin();
checkPlayerWin();
playRandom();
}
checkGame();
if(game == 0 || game == 2){
delay(2000);
int t;
for(t=0;t<9;t+=1){
digitalWrite(computerArray[t],HIGH);
}
}
}

Introduction: Tic Tac Toe Arduino

Step 1: Setting Up the Bread Boards

Step 2: Wiring

Step 3: Code