Finaly i had the mood and time to try one of the Analog Gauges. Please read more to find out more ;)

I created the following Arduino Code. Its not to difficult to read and awesomely short.

I just thought about Eliots Blog Post about State Machines and decided, that i have to sleep over it ;) (Even not sure if possible to use with Arduino...)

/*
 * Increasing and Decreasing Analog Gauge Value via PWM
 * Analog Gauge is attached to pin 9 in series with a ~ 3.3K resistor
 * Crted by Stefan-Xp
 */

const byte GaugePinNo = 9;              // Pin which the Gauge is connected to
const int GaugeDelayBetweenSteps = 50;  // Time Delay, which is taken between the Value changes
byte GaugeValue = 0;                    // Actual Gauge Value
byte State = 0;                         // Actual State: 0 = Count up, 1 = Count down

void setup() { 
  // Set the Pin to Output
  pinMode(GaugePinNo, OUTPUT); 
  
  // Initialise Serial Port
  Serial.begin(9600); 
  Serial.println("Analoginstrument Test");
}

// This function writes the Value to the Output and prints the Value via Serial
byte write_Value (byte Value)
{
  // Set PWM Value
  analogWrite(GaugePinNo, Value);
  // Write Data on Serial Port
  Serial.print("Value: ");
  Serial.println(Value);
  
  // Select next State ...
  if (Value == 0)
    State = 0; // Value reached 0, so beginn to count up
  
  if (Value == 255)
    State = 1; // Value reached 255, so beginn to count down
}

void loop()
{
  // Decide if should count down or up
  if(State)
    GaugeValue--;
  else
    GaugeValue++;   
  
  // Execute
  write_Value(GaugeValue); 
  // Wait for next Cycle
  delay(GaugeDelayBetweenSteps); 
}

Schematic of the Circuit:

Video of the Moving Gauge Value: