This tutorial is to demonstrate all five methods for debouncing switches using single pole-single throw, or single pole-double throw switches. The guide includes the two methods for single pole-double throw (SPDT) switches which require no output delay and the two best methods for interfacing with the more simple single pole-single throw (SPST) switches.
Using the internal cross-coupled nand gating of a D-Type Flip flop provides an excellent Method 3 Debounce identical to Method 2. Note the Q output is normally high and goes low when the switch is activated.
Whenever a single pole-single throw (SPST) switch is used for input into high-speed digital devices, the only thing you can do is to wait out the bounce interval with either hardware or software delays (see Waveform 2 below).