This one is pretty easy, but I thought I would share the working code, I used analog pin0 for input this will give you the high and low values from the sensor on the serial port as well.
byte sensorPin=0;
int latestVal=0;
int maxVal=0;
int minVal=1024;
void setup() {
Serial.begin(9600);
Serial.println("in setup");
}
void loop() {
//Serial.println("In loop");
latestVal = analogRead(sensorPin);
if(latestVal < minVal) {
minVal = latestVal;
}
if(latestVal > maxVal) {
maxVal = latestVal;
}
Serial.print("Max: ");
Serial.print(maxVal);
Serial.print(" Min: ");
Serial.print(minVal);
Serial.print(" Latest: ");
Serial.println(latestVal);
delay(1000);
}