tiny13a

randomLedArray.ino

int timer = 100;

const PROGMEM unsigned int ledPins[] =  
                 { 0,1,2,3,4,0,1,2,3,4,
                   4,3,2,1,0,4,3,2,1,0,
                   0,1,2,3,4,4,3,2,1,0,
                   4,3,2,1,0,0,1,2,3,4,};

const PROGMEM unsigned int stepCount = 10;

unsigned int randomloop;

unsigned long m_w = 1;
unsigned long m_z = 2; 

void setup() {
  for (int thisPin = 0; thisPin < 5; thisPin++) {
    pinMode(thisPin, OUTPUT);
  }

  randomloop = getRandom() %4 -2;
    
}

void loop() {
  // loop from the lowest pin to the highest:
  for (int thisPin = 0; thisPin < randomloop; thisPin++) {
    // turn the pin on:
    digitalWrite(ledPins[(10*randomloop)+thisPin], HIGH);
    delay(timer);
    // turn the pin off:
    digitalWrite(ledPins[(10*randomloop)+thisPin], LOW);
  }
}

unsigned long getRandom()
{
    m_z = 36969L * (m_z & 65535L) + (m_z >> 16);
    m_w = 18000L * (m_w & 65535L) + (m_w >> 16);
    return (m_z << 16) + m_w;  /* 32-bit result */
}