Arduino with two (or more) push buttons

Question

I am trying modify this setup for two push buttons https://www.arduino.cc/en/Tutorial/Button.

The code seems rather trivial

int yellowButtonPin = 2;
int blueButtonPin = 4;
int yellowButtonState = 0;
int blueButtonState = 0;
void setup(){
 Serial.begin(9600);
 pinMode(yellowButtonPin,INPUT);
 pinMode(blueButtonPin,INPUT);
}
void loop(){
 yellowButtonState = digitalRead(yellowButtonPin);
 blueButtonState = digitalRead(blueButtonPin);
 if (yellowButtonState == HIGH && blueButtonState == HIGH){
 Serial.write(3);
 }
 else if (yellowButtonState == HIGH && blueButtonState == LOW){
 Serial.write(2);
 }
 else if (yellowButtonState == LOW && blueButtonState == HIGH){
 Serial.write(1);
 }
 else {
 Serial.write(0);
 }
}

My problem is that there are several ground pins on the Arduino, but only one 5V pin, so I can't just simple double the circuits. Connecting the two circuits to different grounds but the same 5V didn't work out, although it seemed to be a good idea. How should I do this properly? To be honest, I actually would want to have three buttons, but I guess going from two to three will be trivial after going from one to two.

enter image description here

• Majenko: Chances are there is something wrong with how you built your circuit. Using the same 5V pin for both buttons is perfectly acceptable.
• fbence: Do I need different ground though? I'll edit with a circuit drawing in minute.
• Richard Crowley: All the ground connections are identical and connected together. It makes no difference which ground pin your use.
• Majenko: There is only one ground. It may have multiple pins on it, but there is only one. Use whatever ground pin(s) you fancy, they are all the same.
• KIIV: I hope you don't expect characters '0' .. '3' in the Serial Monitor as you are sending characters: NUL, SOH, STX and ETX (ASCII values from 0 to 3) and they might not be visible.

Answer 1

Learn about:

Built-in pullup resistors in Arduino Debouncing

and checks this code: https://blog.adafruit.com/2009/10/20/example-code-for-multi-button-checker-with-debouncing/