Count amount of times a boolean changed value

[kenny11]

I have a photoresistor thats detecting an LED and I want to count the amount of times the LED triggers the photoresistor. The problem is, when I just use a normal (int) counter, the value shoots up as soon as the resistor detects light.

Now I thought I could just use a boolean that switches from false to true when it detects light over a certain threshold, which works, but now I need to count the amount of times it switches. How can I do that?

Here's some piece of code for better understanding

if (lightVal >= 800)
  {
    ticker == true;
  }
  else
  {
    ticker = false;
  }

Now I need to count how many times it went from false to true.

Greetings

[groundFungus]

Look for transitions instead of levels. The state change detection tutorial explains how to do that. Count the times that ticker changes from false to true (positive edge). See also.

[LarryD]

@kenny11

if (lightVal >= 800)

Tell us what this does ?

[kenny11]

oh yeah sure. Thats the intensity of the light which hits the photoresistor. If that value is above 800 (when a laser hits it) it should trigger the counter.

[LarryD]

The loop( ) function is run 1000s of times per second, over and over and over again.

When lightVal >= 800 is true, since loop( ) keeps looping, you will have 1000s of Counts occurring.

---

BTW
ticker == true; should be ticker = true;

= verses ==

[JCA34F]

What is lightVal when laser is ON? When OFF?