/*
Show It
Demonstrates analog input by reading a light sensor on analog pin 0.

Also records the minimum and maximum sensor values that the sensor sees.
Whenever the program reads an analog sensor value that is smaller than the
current minimum, it replaces the recorded minimum with the new value.
Likewise for the maximum value.

Prints out in the form:
current minimum maximum

Lights an LED with an intensity proportional to the light level
that the photocell senses, with LED intensity ranging from 0-255.

Created by Corinna Sherman
22 Sep 2010
*/

int sensorPin = 0; // analog input pin for the photocell
int ledPin = 11; // analog output (PWM) pin for the LED

int sensorValue = 0; // variable to hold the current sensor value
int maxSensorValue = 0; // variable to hold the maximum sensor value
int minSensorValue = 0; // variable to hold the minimum sensor value

String output; // variable to hold the String output: (current max min)
String space; // space character
String intensityLabel; // label for intensity printout

void setup() {

// Initialize the serial communication.
Serial.begin(9600);

// Initialize the sensor value.
sensorValue = maxSensorValue = minSensorValue = analogRead(sensorPin);

// Initialize strings for output.
output = String();
space = String(" ");
intensityLabel = String("ledIntensity = ");
}

void loop() {

// Read the value from the sensor.
sensorValue = analogRead(sensorPin);

// Update the max and min sensor values if applicable.
if (sensorValue > maxSensorValue) {
maxSensorValue = sensorValue;
} else if (sensorValue < minSensorValue) {
minSensorValue = sensorValue;
}

// Print the current, min, and max sensor values.
output = sensorValue + space + minSensorValue + space + maxSensorValue;
Serial.println(output);

// Light the LED with intensity proportional to the light level sensed,
// ranging from 0 to 255.
int ledIntensity = map(sensorValue, minSensorValue, maxSensorValue, 0, 255);
analogWrite(ledPin, ledIntensity);
Serial.println(intensityLabel + ledIntensity);
}