free_love.c

#include <FreqCounter.h>

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

unsigned long frq;

void loop() {
  // Initialize the frequency counter on pin 5
  // Read from counter every 250ms to see how many pulses there are from the fan
  FreqCounter::start(250);

  // Idle until the 250ms have elapsed
  while (FreqCounter::f_ready == 0) 

  // Convert frequency into unsigned long for serial transport
  frq = FreqCounter::f_freq;

  // Since our sensor values are less than 256, we send only the first 8 bits
  frq = frq & 0xff;

  // Send first 8 bits of frequency reading as byte over serial
  Serial.print(frq, BYTE);
}