Buttons

int ledPin = 9; // choose the pin for the LED 
int inputPin1 = 3; // button 1 
int inputPin2 = 2; // button 2 
  
void setup() { 
  pinMode(ledPin, OUTPUT); // declare LED as output 
  pinMode(inputPin1, INPUT); // make button 1 an input 
  pinMode(inputPin2, INPUT); // make button 2 an input 
} 
  
int value = 0; 
void loop(){ 
  if (digitalRead(inputPin1) == LOW) { value--; } 
  else if (digitalRead(inputPin2) == LOW) { value++; } 
  value = constrain(value, 0, 255); 
  analogWrite(ledPin, value); 
  delay(10); 
}