Dimmer Code

//Camille Kauffman
//excercise 5-2 from Getting started with Arduino

const int LED = 9; // the pin for the LED
const int BUTTON = 7; // input pin of the pushbutton

int val = 0; // stores the state of the input pin int old_val = 0; // stores the previous value of "val"
int state = 0; // 0 = LED off while 1 = LED on

int brightness = 128; // Stores the brightness value unsigned long startTime = 0; // when did we begin pressing?
void setup() {

pinMode(LED, OUTPUT); // tell Arduino LED is an output pinMode(BUTTON, INPUT); // and BUTTON is an input

}

void loop() {

val = digitalRead(BUTTON); // read input value and store it // yum, fresh // check if there was a transition
if ((val == HIGH) && (old_val == LOW)) {
state = 1 - state; // change the state from off to on // or vice-versa

startTime = millis(); // millis() is the Arduino clock // it returns how many milliseconds // (this line remembers when the button // was last pressed)
delay(10);

}
// check whether the button is being held down
if ((val == HIGH) && (old_val == HIGH)) 
 {
// If the button is held for more than 500 ms.
if (state == 1 && (millis() - startTime) > 505) 

{
brightness++; // increment brightness by 1 delay(10); // delay to avoid brightness going
// up too fast
if (brightness > 255) 

{ // 255 is the max brightness
brightness = 0; // if we go over 255 // let's go back to 0
 } 
}

}
old_val = val; // val is now old, let's store it
if (state == 1) {

analogWrite(LED, brightness); // turn LED ON at the // current brightness level analogWrite(LED, 0); // turn LED OFF
}else{ 
 analogWrite(LED, 0;)//turn off the led
   }
}