Using one Potentiometer to Control Multiple LEDs at different rates

Using Arduino LEDs and Multiplexing
2

Here's a possible scheme for 2 LEDs that is easily extended to any number of LEDs. [WARNING: untested code!]

const int numLeds = 2;
const int ledPins[numLeds] = { 2, 3 };       // the number of the LED pin
int ledStates[numLeds] = { LOW, LOW };   // ledState used to set the LED
long previousMillis[numLeds] = { 0, 0 };     // will store last time LED was updated
float multipliers[numLeds] = { 0.5, 1.0 };  // the blink rates
int sensorPin = A0;    // select the input pin for the potentiometer
int sensorValue = 0;  // variable to store the value coming from the sensor
long interval = sensorValue; // interval at which to blink (milliseconds)

void setup() {
  unsigned long currentMillis = millis();
  for (int i = 0; i < numLeds; ++i) {
    pinMode(ledPins[i], OUTPUT);
    previousMillis[i] = currentMillis;     
  }
}

void loop()
{
  sensorValue = analogRead(sensorPin);
  unsigned long currentMillis = millis();
  for (int i = 0; i < numLeds ; ++i)
  {
    unsigned long target = (unsigned long)(sensorValue * multipliers[i]);
    if(currentMillis - previousMillis[i] >= target) {
      previousMillis[i] += target;   
      if (ledStates[i] == LOW)
        ledStates[i] = HIGH;
      else
        ledStates[i] = LOW;
      digitalWrite(ledPins[i], ledStates[i]);  
    }
  }
}