int sensorPin = A0;
int led = 6;
void setup() {
Serial.begin(9600);
pinMode(sensorPin, INPUT);
pinMode(led, OUTPUT);
}

void loop() {
int sensorValue;
sensorValue = analogRead(sensorPin);
int b;
b = sensorValue/4;
analogWrite(led, b);
Serial.print("sensor = ");
Serial.print(sensorValue);
Serial.print("    b=");
Serial.println(b);
delay(500);
}