Generating Clean Clock Pulses using Opto-Coupler

[ZaeemAhmad]

I am using OMRON EE-SM3 Opto-Switch (Sensor TX + RX Unit) for inputting clock pulses to uController through its timer pin. The problem is that when I pass an opaque object through its slit once, it counts it multiple times (i.e. counter increments more than once).
Is there any remedy circuit for such a problem, so in result I could get one pulse per pass. I don't intend to use any Shmitt-Trigger device. What is the most economical solution. The circuit I am using currently is the one given in the test circuit section of the sensor's datasheet given above in the link.

 

[FvM]

I don't intend to use any Shmitt-Trigger device.

Your choice. It's the only way to produce a clean digital signal in this case. Low pass filtering in front of the schmitt-trigger can be required in addition, if the object is moving very slow and interfering AC light (e.g. from CFL) or electrical noise is present.

What is the most economical solution.

Provide a software based time filter. But you can't used the timer input directly then.

 

[andre_luis]

What is distance between sensor and circuitry ?
Cabling is proper to the signal path ?

+++

 

[dick_freebird]

What does the signal look like out of the optocoupler? Do
you even know? If you don't, then speculating how to fix
the larger assembly is just rolling the dice.

 

[ZaeemAhmad]

Thank you all! The problem was solved by using a 555 timer at the output of the slit-hole sensor and connecting the output of 555 timer to the uC. The circuit diagram can be downloaded from **broken link removed**...