Frequency measurement

I am trying to measure to measure the frequency of strobe light using a photoresistor by employing the Freqmeasure library provided in the link below:

Has anyone had success in getting this library to run?

This library seems perfect for my application but upon uploading and viewing the serial monitor it is blank. I have seen members in other threads discuss the successful use of this library.

Any amount of advice is very, very appreciated. I am simply trying to measure the dominant frequency(ies) of an analog signal, and have not succeeded with any other libraries i have tried. Again, thank you for all input, any wisdom is immensely appreciated.

(Also, the website states input to pin 8 on the UNO. how can the UNO read analog signal from pin 8.

using a photoresistor

Have you proven this part of the circuit?

Thanks very much for quick reply. yes when introduced to varying levels of light, the serial monitor responds accordingly

Is your serial monitor baud rate the same as the sketches baud rate?
Show use your sketch.

yes sir, both at 57600 baud rate

Show us your sketch.

Here it is thanks again for the help. I appreciate your time

/* FreqMeasure - Example with serial output
 * This example code is in the public domain.
#include <FreqMeasure.h>

void setup() {

double sum=0;
int count=0;

void loop() {
  if (FreqMeasure.available()) {
    // average several reading together
    sum = sum +;
    count = count + 1;
    if (count > 30) {
      double frequency = F_CPU / (sum / count);
      sum = 0;
      count = 0;

I will try it here.
If you have a scope make sure the I/P to the Arduino is going to 0V and back to +5V.

Show us a diagram of your circuit.

I have a drawing but can’t seem to figure out how to attach it.

however i’ll do my best to explain my setup

5 volts ====>(photoresistor)—(resistor)-----------(Ground)
(pin 8)

not sure how the analog signal is read from pin 8?, but this is the setup shown on the link

crap hahah, the smiley face should read (pin 8)

Got it working on an Arduino UNO.

Show us your schematic.
At the bottom of the I/P screen click on "Additional Options" then Browse to your image file and then post.

wow not sure what is happening lol, i’m trying to type (pin eight) on the arduino

Are you using a Teensy 1.0?

Here is the schematic
I am using an arduino UNO.
Again i really appreciate your help, thank you.

Arduino circuit.png

Arduino circuit1.png

You are not reading the A0 i/p in your sketch.
You have to use D8 (on the UNO) as the input before the frequency sketch you showed will work.

First add code to the frequency sketch which reads the analog input.
Set up a threshold to determine a light flash.
Toggle a digital pin say D2 every time the threshold is met.
Connect pin 2 to pin 8.

Awesome, thank you so much for your help. Greatly appreciated Larry D. I will definitely try this out .