Tut 2

fade2.ino

void fade2()
{
  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
    // have passed since the board has
    // been reset.
    // (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) > 900) 
    // last number is how long the led will stay at max before 
    //going through this if statement
    {
      brightness++; // increment brightness by 1 
      delay(60); // delay to avoid brightness going
      // up too fast
      if (brightness > 55)
      { 
        brightness = 0; // if we go over 255 it goes 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
  }
  else
  {
    analogWrite(LED, 0); // turn LED OFF
  }
}

lightsource_blink.ino

void lightsource_blink()
{
 val = analogRead(0); // read the value from // the sensor
analogWrite(LED, val/4); // turn the LED on at // the brightness set
                           // by the sensor
delay(10); // stop the program for // some time
}

serial.ino

void serial()
{
  val = analogRead(SENSOR); // read the value from // the sensor
  Serial.print("val = ");
  Serial.println(val); // print the value. adds new line after// the serial port
  delay(100); // wait 100ms between // each send
}

Tut2.ino

const int LED = 9; // the pin for the LED
int i = 0; // We'll use this to count up and down
int led = 13;

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

const int SENSOR = 0;

void setup()
{
  pinMode(LED, OUTPUT); // LED is an output
  pinMode(led, OUTPUT); // LED is an output
  pinMode(BUTTON, INPUT); // BUTTON is an input
  Serial.begin(9600); // open the serial port to send
  // data back to the computer at
  // 9600 bits per second
}
void loop()
{
  // fade2();
  //lightsource_blink();
  serial();
}