Homemade wheel encoder

Basically I just printed out one of these (laser printer recommended):

...And attached it to a wheel (double sided tape recommended).

Then I hooked up one of these (a 2$ IR sensor: QRB1134):

...And attached it to the motor pointing towards the wheel.

I've been testing it a bit with a few lines of Arduino code and damnit it works :D I'm now able to measure how much the wheel is rotating and therefore calculate how far a robot is moving. I just love it when these cheap lowtech solutions work.

Here are some photos (sorry about the bad quality):

UPDATE: 

Here is the schematic I used to hook up the QRB1134 sensor:

I used a 0.1uF ceramic cap. Don't know if that's what was intended? It does have a + indicating a polarized cap, but I dunno? Man I wish people would write the kind of cap you're supposed to use, but apparently that's obvious to everyone but me :/ If anyone has a suggestion of what to use I'm open?

Here is the Arduino code I used for testing:

#define IOP 14
#define PWM 3

int val_new;
int val_old;
int clicks = 0;
int turns = 0;

void setup() {
    Serial.begin(115200);
    pinMode(IOP, INPUT);
    val_new = digitalRead(IOP);
    val_old = val_new;
}

void loop() {
    analogWrite(PWM, 80);
    val_new = digitalRead(IOP);
   
    if(val_new != val_old) {
        if(clicks == 40) {
            clicks = 1;
            turns++;
            Serial.print("TURNS: ");
            Serial.println(turns);  
        }
        else clicks++;
       
        Serial.print("CLICKS: ");
        Serial.println(clicks);

        val_old = val_new;
    }
}

Basically I just add 1 to the variable click every time the color in front of the sensor changes. When I reach 40 clicks I reset the variable click and add 1 to the variable turns. And off course I'm logging everthing through serial for testing. That's it :)