Clarence's Wicked Mind

// variables for input pin and control LED
  int analogInput = 1;
  int LEDpin = 13;
  int prev = LOW;
  int refresh = 1000;
  float vout = 0.0;
  float vin = 0.0;
  float R1 = 50000.0;    // !! resistance of R1 !!
  float R2 = 4300.0;     // !! resistance of R2 !!
  
// variable to store the value 
  int value = 0;
  
 
void setup(){

  // declaration of pin modes
  pinMode(analogInput, INPUT);
  pinMode(LEDpin, OUTPUT);
  
  // begin sending over serial port
  Serial.begin(9600);
}

void loop(){
  // read the value on analog input
  value = analogRead(analogInput);
  //Serial.print("value=");
  //Serial.println(value);

  if (value >= 1023) {
    Serial.println("MAX!!");
    delay(refresh);
    return;
  }
  else if (value <= 0) {
    Serial.println("MIN!!");
    delay(refresh);
    return;
  }

  // blink the LED
  if (prev == LOW) {
    prev = HIGH;
  } else {
    prev = LOW;
  }
  digitalWrite(LEDpin, prev); 

  // print result over the serial port
  vout = (value * 5.0) / 1024.0;
  vin = vout / (R2/(R1+R2));
  
  //Serial.print("vout=");
  //Serial.println(vout);
  
  Serial.print(vin);
  Serial.println(" volt");

  // sleep...
  delay(refresh);	
}