Схема на макетке

Скетч

            #define FIRST_LED_PIN 2
#define LAST_LED_PIN 11
#define POT_PIN A0


void setup()
{
  for (int pin = FIRST_LED_PIN; pin <= LAST_LED_PIN; ++pin)
    pinMode(pin, OUTPUT);
  pinMode(POT_PIN, INPUT);
}
 
void loop()
{
  int cnt = analogRead(POT_PIN) / 102;
  for (int pin = FIRST_LED_PIN; pin < FIRST_LED_PIN + cnt; ++pin)
    digitalWrite(pin, HIGH);
  for (int pin = FIRST_LED_PIN + cnt; pin <= LAST_LED_PIN; ++pin)
    digitalWrite(pin, LOW);
}