/*
 LED Dimmer By KB1UIF (A.Tedds) 2016
 The circuit:
 Connect the LED from pin 9 to ground via a 200 Ohm current limiting Resistor.
*/

 // the pin that the LED is connected to
const int ledPin = 9;      

void setup()
{
  // Initialize the serial communication:
  Serial.begin(9600);
  // Initialize the ledPin as an output:
  pinMode(ledPin, OUTPUT);
  // Send Instructions via the Serial Monitor:
  Serial.println("Enter an LED brightness value from 0 to 255 "); 
}

void loop()
{
  // check if any data has been sent from the computer:
  if (Serial.available()) 
  {
    // Read the most recent input to serial monitor (which will be from 0 to 255):
   int brightness = Serial.parseInt();
   
   // check that the input value is between 0 and 255:
    if (brightness >= 0 && brightness <= 255) 
   {
    // set the brightness of the LED:
    analogWrite(ledPin, brightness);
    
    // Confirm the entered value on serial monitor screen:
    Serial.print("You entered a value of ");
    Serial.println(brightness);
    // repeat:
   }
  }
}