Button Control
Sample API functions for using push-buttons.
See button.h for source code.
Button State Definitions#
A set of numerical definitions for use with the button APIs indicating the state of a button.
Button state is pressed.
Button state is released.
Functions#
Initializes the buttons. This function is automatically called by halInit().
Returns the current state (pressed or released) of a button.
A callback called in interrupt context whenever a button changes its state.
Button State Definitions Documentation#
Function Documentation#
halInternalInitButton
void halInternalInitButton (void )
Initializes the buttons. This function is automatically called by halInit().
Type | Direction | Argument Name | Description |
---|---|---|---|
void | N/A |
halButtonState
uint8_t halButtonState (uint8_t button)
Returns the current state (pressed or released) of a button.
Type | Direction | Argument Name | Description |
---|---|---|---|
uint8_t | N/A | button | The button being queried, either BUTTON0 or BUTTON1 as defined in the appropriate BOARD_HEADER. |
Note
This function is correlated with halButtonIsr() and so returns the shadow state rather than reading the actual state of the pin.
Returns
BUTTON_PRESSED if the button is pressed or BUTTON_RELEASED if the button is not pressed.
halButtonIsr
void halButtonIsr (uint8_t button, uint8_t state)
A callback called in interrupt context whenever a button changes its state.
Type | Direction | Argument Name | Description |
---|---|---|---|
uint8_t | N/A | button | The button which has changed state, either BUTTON0 or BUTTON1 as defined in the appropriate BOARD_HEADER. |
uint8_t | N/A | state | The new state of the button referenced by the button parameter, either BUTTON_PRESSED if the button has been pressed or BUTTON_RELEASED if the button has been released. |
Application Usage:\n Must be implemented by the application. This function should#
contain the functionality to be executed in response to changes of state in each of the buttons, or callbacks to the appropriate functionality.