Help with logic for optical encoder?

Using Arduino Programming Questions
1 
int encoder(){
  
  int read = digitalRead(4);
 if(read != lastRead){
 	var = 1;
 }
  if((var == 1) && (read != lastRead)) {
    encoderPos++;
    var = 0;
    lastRead = read;
  }

 }

Is that wrong? Can someone tell me a right algorithm?

The sensor is working well, but looks like encoderPos isn't getting bigger.

2

There is more than one kind of encoder. Please post the vendor link for the encoder.
As an example here is a link for quadrature encoder , but does anyone but you know if that is what you are using ?
http://playground.arduino.cc/Main/RotaryEncoders

3

It's a optical sensor.

4

(deleted)

5

It's a optical sensor.

please post the vendor link for the encoder.

(is this too vague ? Do you understand what this means ?)

Someone?

(please explain to the OP that there is more than one kind of optical encoder in the world)

Have you heard of Google ?

http://multimechatronics.com/images/uploads/design/2012/Optical%20Encoder%20and%20the%20Arduino%202012.pdf
file:///C:/Users/Robert/Downloads/01-Encoder.pdf
[ https://www.youtube.com/watch?v=xgIubJHVRwg ](http:// https://www.youtube.com/watch?v=xgIubJHVRwg)

see Reply#14 in this post:
[ http://forum.arduino.cc/index.php/topic,44817.0.html ](http:// http://forum.arduino.cc/index.php/topic,44817.0.html)

6

it's just a normal optical sensor

The logic would be the same anyway, so, will you try to help me with the logic?

7

it's just a normal optical sensor

Then your post title is incorrect, isn't it ? (because your post has nothing to do with ENCODERs because you don't know a sensor from an encoder) (right ?)

If it is not an encoder, maybe you should stop treating it like one ? (or calling it one)

The sensor is working well, but looks like encoderPos isn't getting bigger.

I'm just sayin'......

You need to tell us (or post a photo) how you are using this reflective sensor. What is it installed on and what is it detecting ?
Also, what is the distance in mm from the sensor to the target object ?
Is being used as an RPM sensor ?
https://www.google.com/search?q=arduino+reflective+rpm+sensor&tbm=isch&imgil=nT45GiVoZqXm6M%253A%253By37hZ2zN5cCiFM%253Bhttp%25253A%25252F%25252Fwww.8051projects.net%25252Fnews-i178-contactless-digital-tachometer-using-pic-microcontroller.html&source=iu&fir=nT45GiVoZqXm6M%253A%252Cy37hZ2zN5cCiFM%252C_&usg=__zNtyRU8H9CdE4ixXrdvzlTtIOkU%3D&sa=X&ei=tEgCVKWdNauWjAL_24HIBQ&ved=0CCQQ9QEwAg&biw=1394&bih=650#facrc=_&imgdii=_&imgrc=nT45GiVoZqXm6M%253A%3By37hZ2zN5cCiFM%3Bhttp%253A%252F%252Fwww.8051projects.net%252Fimages%252Ftacho-logic.jpg%3Bhttp%253A%252F%252Fwww.8051projects.net%252Fnews-i178-contactless-digital-tachometer-using-pic-microcontroller.html%3B500%3B359

Have you seen the schematic at this link ?

How is your sensor wired ? Post a schematic of your sensor wiring. If necessary, draw it on a piece of printer paper and taka a photo and post that.

The sensor is working well

Based on what ?

Have you seen this tutorial ?
http://www.seeedstudio.com/wiki/Grove_-_Infrared_Reflective_Sensor

  #include <TimerOne.h>
unsigned int counter=0;
void blink()
{
  counter++;
} 
void timerIsr()
{
  Timer1.detachInterrupt();  //disable the timer1
  Serial.print("The speed of the motor: "); 
  Serial.print(counter,DEC);  
  Serial.println("round/s"); 
  counter=0;  
  Timer1.attachInterrupt( timerIsr );  //enable the timer1
}
void setup() 
{
  Serial.begin(9600);
  Timer1.initialize(1000000); // set a timer of length 1sec
  attachInterrupt(0, blink, RISING);  //INT0
  Timer1.attachInterrupt( timerIsr ); // attach the service routine here
} 
void loop()
{
  ;  //do nothing
}