Breadboard Button

Breadboard Button
a breadboard friendly debounced button with toggle and pulse functions. Use it for glitch-free input to your project. The board outputs positive and negative logic button state (active while the button is pressed). An additional FCN output toggles on each press or generates a 10 millisecond pulse on each press with 50 pulses/second automatic repeat.

Design Documents

Schematic Diagram	schematic_J129_breadboard_button.pdf
Bill of Materials	Breadboard Button BOM.pdf
PCB Gerbers	gerbers_J129_breadboard_button.zip
Source Code	code_J129_breadboard_button.zip

Specifications

Power Requirement	3.3V to 5.0V
Output	Logic level, 25mA maximum

Operation
The Breadboard Button PCB is designed to plug into two rows of a standard breadboard and remain stable, like this:

There are 2 power pins

VCC	Logic supply voltage, 3.3V to 5.0V
GND	Logic ground

There are 3 output pins

BTN	Debounced button, positive logic (HIGH when the button is pressed)
/BTN	Debounced button, negative logic (LOW when the button is pressed)
FCN	Toggle or Pulse output

The BTN and /BTN outputs are real simple; as long as the button is pressed the output is active.

The two pin jumper selects the FCN pin operation:

No Jumper	FCN pin toggles on each press
Jumper Installed	FCN pin pulses for 10 msec, then repeats at 50/sec after 1 second (press button to generate 1 pulse, hold to generate continuous pulses at 50Hz)
The onboard LED indicates the FCN pin output state

Adding a jumper across the two bottom feet pins changes the button FCN output from toggle to pulse.