Action is being performed three times - button

Question

I am creating an Arduino project that plays Rock Paper Scissors.
I have a part of the code reading the value of the button and whenever I click only one button, it outputs three times (View code and images of serial monitor to understand what I mean, I can't really explain it)
Here is my code:
// constants won't change. They're used here to
// set pin numbers:
const int buttonPin1 = A0; // the number of the pushbutton pin
const int buttonPin2 = A1;
const int buttonPin3 = A2;
const int ledPin = 12; // the number of the LED pin
// variables will change:
int buttonState1 = 0; // variable for reading the pushbutton status
int buttonState2 = 0;
int buttonState3 = 0;
char * choices[3] = {"Rock", "Paper", "Scissors"};
char * finalResult[3] = {"You Lost", "You Won!", "It's a Tie"};
byte Human = 0, Computer = 0, FR = 0;
char result[25];
void setup() {
// initialize the LED pin as an output:
pinMode(ledPin, OUTPUT);
// initialize the pushbutton pin as an input:
pinMode(buttonPin1, INPUT);
pinMode(buttonPin2, INPUT);
pinMode(buttonPin3, INPUT);
digitalWrite(ledPin,LOW);
Serial.begin(9600);
unsigned long R;
randomSeed(R);
}
void loop(){
int choice = random(1,4);
int pick;
// read the state of the pushbutton value:
// check if the pushbutton is pressed.
// if it is, the buttonState is HIGH:
Serial.println("Entering Reading Loop...");
while(true)
{
buttonState1 = digitalRead(buttonPin1);
buttonState2 = digitalRead(buttonPin2);
buttonState3 = digitalRead(buttonPin3);
if (buttonState1 == HIGH && buttonState2 == LOW && buttonState3 == LOW) {
// turn LED on:
Throw('1');
} else if (buttonState1 == LOW && buttonState2 == HIGH && buttonState3 == LOW) {
// turn LED on:
pick = 2; //Paper
Throw('2');
}else if (buttonState1 == LOW && buttonState2 == LOW && buttonState3 == HIGH) {
// turn LED on:
pick = 3; //Scissor
Throw('3');
}
}
}
void Throw(char H)
{
bool thrown = false;
H -= '0'; //convert ascii to decimal
H -= 1; // instead of 1,2,3, H is now 0,1,2
byte C = random(0, 3);
sprintf(result, "The Computer chose: %s, You chose: %s", choices[C], choices[H]);
Serial.println(result);
if ( C == H)
Serial.println(F("Its a TIE"));
else
{
switch (C)
{
case 0:
switch (H)
{
case 1:
Serial.println(F("Paper wraps Rock, You WIN!"));
Human++;
break;
case 2:
Serial.println(F("Rock crushes Scissors, You LOSE!"));
Computer++;
break;
}
break;
case 1:
switch (H)
{
case 0:
Serial.println(F("Paper wraps Rock, You LOSE!"));
Computer++;
break;
case 2:
Serial.println(F("Scissors cuts Paper, You WIN!"));
Human++;
break;
}
break;
case 2:
switch (H)
{
case 0:
Serial.println(F("Rock crushes Scissors, You WIN!"));
Human++;
break;
case 1:
Serial.println(F("Scissors cuts Paper, You LOSE!"));
Computer++;
break;
}
break;
}
}
}
This is what I'm getting on the serial monitor when I click only ONE button(the rock button)
http://gyazo.com/ceb5c8329993339368cf5d52181ed4d7
As you can see, it chooses the right option for the button but it calls the throw function 3 times.
http://playground.arduino.cc/Main/RockPaperScissors)

Answer 1

From the Arduino docs they recommend using a Debounce strategy for handling inputs.
Without debouncing, pressing the button once can appear to the code as
multiple presses.
http://www.arduino.cc/en/Tutorial/Debounce
Here is another example illustrating the Debounce technique:
http://danthompsonsblog.blogspot.com/2011/12/arduino-push-button-onoff-example.html

Answer 2

There are pull-up resistors built in to the arduino that will allow you to filter out the erratic electrical signal you get when pressing a button. See the section on INPUT_PULLUP here.

Answer 3

I don't what the exact issue was but, I added a delay in my throw function and it stopped outputting the serial print statement 3 times!
Here is my updated function:
void Throw(char H)
{
bool thrown = false;
H -= '0'; //convert ascii to decimal
H -= 1; // instead of 1,2,3, H is now 0,1,2
byte C = random(0, 3);
sprintf(result, "The Computer chose: %s, You chose: %s", choices[C], choices[H]);
Serial.println(result);
delay(500);
if ( C == H)
Serial.println(F("Its a TIE"));
else
{
switch (C)
{
case 0:
switch (H)
{
case 1:
Serial.println(F("Paper wraps Rock, You WIN!"));
Human++;
break;
return;
case 2:
Serial.println(F("Rock crushes Scissors, You LOSE!"));
Computer++;
break;
}
break;
case 1:
switch (H)
{
case 0:
Serial.println(F("Paper wraps Rock, You LOSE!"));
Computer++;
break;
case 2:
Serial.println(F("Scissors cuts Paper, You WIN!"));
Human++;
break;
}
break;
case 2:
switch (H)
{
case 0:
Serial.println(F("Rock crushes Scissors, You WIN!"));
Human++;
break;
case 1:
Serial.println(F("Scissors cuts Paper, You LOSE!"));
Computer++;
break;
}
break;
}
}
}