This module is great for adding a bit of randomness to sequences for example. You input a clock signal and output five variations of the same signal with different probabilities.

Original project page: Here

#define CLOCK_IN 0 

#define LED_OUT_START 2 
#define POT_START 1 

#define LED_COUNT 5 

const byte outputCount = 5; 
bool state = false; 

void setup() { 
  
  Serial.begin(9600); 

  for (byte i = 0; i < LED_COUNT; i++) { 
    byte pinPosition = LED_OUT_START + i*2; 
    pinMode(pinPosition, OUTPUT); 
    pinMode(pinPosition  +1, OUTPUT); 
  } 
  
  randomSeed(analogRead(7)); 
} 

void loop() { 


  int clockIn = analogRead(CLOCK_IN); 
  bool clockInState = (clockIn > 200); 

  if (clockInState != state) { 
    
    state = clockInState; 
    
    if (clockInState) { 

      for (byte i = 0; i < LED_COUNT; i++) { 
        long randomValue = random(1024); 

        long potValue = analogRead(POT_START + i); 

        bool state = potValue >= randomValue; 

        byte pinPosition = LED_OUT_START + i*2; 
        digitalWrite(pinPosition, state ? HIGH : LOW); 
        digitalWrite(pinPosition + 1, state ? HIGH : LOW); 
        
      } 
 
    } else { 
      for (byte i = 0; i < LED_COUNT; i++) { 
        byte pinPosition = LED_OUT_START + i*2; 
        digitalWrite(pinPosition, LOW); 
        digitalWrite(pinPosition + 1, LOW); 
      } 
    } 
  } 

  
}