I have an existing circuit for a specific purpose. I want to re-use this circuit by slightly modifying the external components. The purpose is shown below:
My questions are:
1. Any suggestions for the mechanical button I can use?
2. What kinds of the circuits should I develop to make it functional? It is OK to generate more than one digital signal "1" when I press the physical button only once.
I think we need to see how it connects to your circuit. The answer to your problem depends on whether the sensor side is connected so it lifts the output signal high or whether it pulls it low. It certainly seems possible though but beware that in some designs the LED side is pulsed rapidly (thousands of times a second) and whether the sensor detects the pulses decides whether it thinks it sees a reflection or not. It is a system that gives better immunity to background light but it also makes it difficult to simulate the pulses with a simple switch.
Stupid question, maybe: Why mess around with the sensor side of things, why don't you just modify the output circuit to be controlled by the switch? And what do you mean 'it transmits a 1'? Is it a serial stream, or do you mean it goes high? And, what do you mean "It is OK to generate more than one digital signal "1"? As Brian says, show us your hardware.