Random Periodicity Test Code for arduino (compiled in Arduino IDE)

rand-period-test.c

long rand_i, rand_j, rand_k;
unsigned long i = 0, j = 0, k = 0;

void setup() {
  // put your setup code here, to run once:
  rand_i = random();
  rand_j = random();
  rand_k = random();
  Serial.begin(9600);
  while (!Serial) {}
  Serial.print("starting num rand_i: "); Serial.println(rand_i, HEX);
  Serial.print("starting num rand_j: "); Serial.println(rand_j, HEX);
  Serial.print("starting num rand_k: "); Serial.println(rand_k, HEX);
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.print("using rand_k");Serial.println(rand_k);
}

void loop() {
  // put your main code here, to run repeatedly:
  if ((i % 1000000) == 0) {
    Serial.print("up to "); Serial.print(i); Serial.println(" iterations");
  }
  if (random() == rand_k) {
    Serial.print("MATCH!! We got a match on "); Serial.print(rand_k); Serial.print(" in "); Serial.print(i, HEX); Serial.println(" operations.");
    //i = 0;
    while(true){
      Serial.print("MATCH!! We got a match on "); Serial.print(rand_k); Serial.print(" in "); Serial.print(i, HEX); Serial.println(" operations.");
      digitalWrite(LED_BUILTIN, HIGH);
      delay(50000);
      digitalWrite(LED_BUILTIN, LOW);
      delay(500);
    }; // stop the duino so we can see what the magic number is :-P Keep printing in case the serial port goes to sleep...
  }
  i++;
}