My latest musings with an Arduino

led-with-potentiometer.c.ino

#include <math.h>

/*
  AnalogReadSerial

  Reads an analog input on pin 0, prints the result to the Serial Monitor.
  Graphical representation is available using Serial Plotter (Tools > Serial Plotter menu).
  Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.

  This example code is in the public domain.

  http://www.arduino.cc/en/Tutorial/AnalogReadSerial
*/

int led = 9;           // the PWM pin the LED is attached to
int brightness = 0;    // how bright the LED is
int fadeAmount = 5;    // how many points to fade the LED by
int maxFadeAmount = 130;

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);

  // declare pin 9 to be an output:
  pinMode(led, OUTPUT);
}

int readInput() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // print out the value you read:
  //delay(1);        // delay in between reads for stability
  return sensorValue;
}

void fadeLed(float percentage) {
  // set the brightness of pin 9:
  Serial.println(maxFadeAmount * percentage);  
  analogWrite(led, (maxFadeAmount * percentage));
}

void blinkLed(float percentage) {
  // set the brightness of pin 9:
  analogWrite(led, brightness);

  fadeAmount = maxFadeAmount * percentage * ((fadeAmount > 0) ? 1 : (-1));

  // change the brightness for next time through the loop:
  brightness = brightness + fadeAmount;
    Serial.print(brightness);  
    Serial.print(", ");  
    Serial.println(fadeAmount);  

  // reverse the direction of the fading at the ends of the fade:
  if (brightness <= 0 || brightness >= 255) {
    if (brightness < 0) brightness = 0;
    if (brightness > 255) brightness = 255;
 
    fadeAmount = -fadeAmount;
  }
  // wait for 30 milliseconds to see the dimming effect
  // delay(30);
}

// the loop routine runs over and over again forever:
void loop() {
  int sensorValue = readInput();
  if (sensorValue <= 10) {
  sensorValue = 11;
  //Serial.println(sensorValue);  
  } 
  float percentage = sensorValue / 1024.0;
  Serial.print(percentage);  
  Serial.print("; ");  

  blinkLed(percentage);
  //fadeLed(percentage);
  // wait for 30 milliseconds to see the dimming effect
  delay(30);  
}