/KeySwitch

JavaScript-like button and switch callback binding for Arduino

Primary LanguageC++GNU General Public License v3.0GPL-3.0

KeySwitch

JavaScript-like button and switch callback binding for Arduino

Installation 1

From the KeySwitch repo, select Clone or download > Download ZIP, or use the direct download link.

In the Arduino IDE, navigate to Sketch > Include Library > Add .ZIP Library. At the top of the drop down list, select the option to Add .ZIP Library.

Return to the Sketch > Include Library menu. You should now see the library at the bottom of the drop-down menu. It is ready to be used in your sketch. The zip file will have been expanded in the libraries folder in your Arduino sketches directory.

Example Code

Two code examples are provided:

OnKey

Demonstrates setting simple button bindings using pre-defined void->void functions.

Lambda

Demonstrates use of C++ lamabdas for cleaner callback handling.

MacroPad

Create a 2-Key macro keypad that copies and pastes. Note: Given example uses the TrinketKeyboard library for the ATtiny85 (Digispark, etc), but other keyboard libraries can be used as well.

LEDCycle

Re-implement of Adafruit NeoPixel butoncycler example.

Class: KeySwitch

Constructors:

KeySwitch(uint8_t pin, bool invert=false);

Bind digital pin state changes to function callbacks.

Name Type Description
pin uin8t_t Pin number or alias to bind class
invert bool Invert the button state
FALSE Pin is passive low (Pulled down) and high when pressed.
TRUE Pin is passive high (Pulled up) and low when pressed

Returns: A new KeySwitch class instance.

Methods:

void begin(void);

Bind to the digital IO pin and begin listening to the switch.

void update(void);

Poll IO state for changes. Triggers callbacks if bound.

bool isKeyDown(void) const;

Is the button currently down? See: isPressed

Returns: bool TRUE if the button is down.

bool isKeyUp(void) const;

Is the button currently up?

Returns: bool TRUE if the button is up.

bool isPressed(void) const;

Is the button currently pressed?

Returns: bool TRUE if the button is pressed.

bool isKeyHeld(void) const;

Is the button currently held?

Returns: bool TRUE if the button has been held for longer than the configured timeout.

void onKeyDown(void (*callback)());

Bind a callback that triggers once, every time the button is pressed.

Name Type Description
callback void * Function to invoke when button is pressed

void onKeyUp(void (*callback)());

Bind a callback that triggers once, every time the button is released.

Name Type Description
callback void * Function to invoke when button is released

void onPressed(void (*callback)());

Bind a callback that triggers continuously as long as the button is pressed.

Name Type Description
callback void * Function to invoke when the button is pressed

void onKeyHeld(void (*callback)(), uint16_t hold_time);

Bind a callback that triggers once, every time the button is held longer than hold_time.

Name Type Description
callback void * Function to invoke when button is held.
hold_time uint16_t How long must the button be held before invoking the callback.

License and Author

2019 Ian McLinden under the GNU General Public License v3.0. Use at your own risk, author retains no liability for misuse.

References

1) Installation instructions provided in part from the official Installing Additional Arduino Libraries guide.

2) Library format based in part on the Arduino Libraries documentation, and on the Arduino Test Library Implementation