Macros
#define	BUTTON_NOT_PUSHED 0

#define	BUTTON_PUSHED 1

#define	SWITCH_OFF 0

#define	SWITCH_ON 1

Enumerations
enum	button_index_t { BUTTON0 , BUTTON1 , BUTTON2 , BUTTON3 , NUM_BUTTONS }

enum	switches_index_t { SWITCH0 , SWITCH1 , NUM_SWITCHES }

Functions
void	switches_init (void)

void	switches_destroy (void)

void	buttons_init (void)

void	buttons_destroy (void)

int	get_button_state (const int button)

int	wait_until_button_state (const int button, const int state)

int	sleep_msec_button_pushed (const int button, const int msec)

void	sleep_msec_buttons_pushed (int button_states[], const int ms)

int	wait_until_button_pushed (const int button)

int	wait_until_button_released (const int button)

int	wait_until_any_button_pushed (void)

int	wait_until_any_button_released (void)

int	get_switch_state (const int switch_num)

Detailed Description

Wrappers to simplify the use of buttons.

Buttons are numbered 0..NUM_BUTTONS-1, and return values are BUTTON_PUSHED and BUTTON_NOT_PUSHED
Switches are numbered 0..NUM_SWITCHES-1, and return values are SWITCH_ON and SWITCH_OFF.
wait_ functions return early, i.e. as soon as the stated condition is true.
sleep_ functions do not return early, i.e. always wait until the specified number of milliseconds.

An example of how to use this library.

#include <libpynq.h>
int main (void)
{
  // initialise all I/O
  pynq_init();
  buttons_init();
 
  printf("Waiting until button 0 is pushed...\n");
  printf("Waited %d milliseconds\n\n", wait_until_button_pushed(0));
  printf("Waiting until button 0 is released...\n");
  printf("Waited %d milliseconds\n\n", wait_until_button_released(0));
 
  // clean up after use
  buttons_destroy();
  pynq_destroy();
  return EXIT_SUCCESS;
}

Buttons can also be used through GPIO (see gpio.h and pinmap.h). Note that GPIO numbering (SWB_BTN0..SWB_BTN3) is then used instead of 0..NUM_BUTTONS-1 (BUTTON0..BUTTON3). GPIO return values are GPIO_LEVEL_LOW/HIGH instead of BUTTON_(NOT_)PUSHED.

Switches can also be used through GPIO (see gpio.h and pinmap.h). Note that GPIO numbering (SWB_SW0..SWB_SW1) is then used instead of 0..NUM_SWITCHES-1 (SWITCH0..SWITCH1). GPIO return values are GPIO_LEVEL_LOW/HIGH instead of SWITCH_ON/OFF.

Macro Definition Documentation

◆ BUTTON_NOT_PUSHED

#define BUTTON_NOT_PUSHED 0

Definition at line 74 of file buttons.h.

◆ BUTTON_PUSHED

#define BUTTON_PUSHED 1

Definition at line 75 of file buttons.h.

◆ SWITCH_OFF

#define SWITCH_OFF 0

Definition at line 76 of file buttons.h.

◆ SWITCH_ON

#define SWITCH_ON 1

Definition at line 77 of file buttons.h.

Enumeration Type Documentation

◆ button_index_t

enum button_index_t

Enum of buttons.

Functions use a button numbered from 0..NUM_BUTTONS-1. Alternatively, you can use BUTTONi instead of just i if you find that clearer.

Enumerator
BUTTON0
BUTTON1
BUTTON2
BUTTON3
NUM_BUTTONS

Definition at line 86 of file buttons.h.

◆ switches_index_t

enum switches_index_t

Enum of switches. Functions use a switch numbered from 0..NUM_SWITCHES-1. Alternatively, you can use SWITCHi instead of just i if you find that clearer.

Enumerator
SWITCH0
SWITCH1
NUM_SWITCHES

Definition at line 94 of file buttons.h.

Function Documentation

◆ buttons_destroy()

void buttons_destroy ( void )

Unitialize the buttons.

Definition at line 50 of file buttons.c.

◆ buttons_init()

void buttons_init ( void )

Initialise the buttons before they can be used.

Definition at line 39 of file buttons.c.

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◆ get_button_state()

int get_button_state ( const int button )

Return the state of the button (BUTTON_(NOT_)PUSHED).

Parameters

button The button the state of which is returned.

Warning: Fails with program exit when button is outside valid range.; Fails with program exit when the direction of the button was not set to input (e.g. because buttons_init was not called before).

Definition at line 71 of file buttons.c.

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◆ get_switch_state()

int get_switch_state ( const int switch_num )

Returns: The state of the switch number (1 for on, 0 for off).

Warning: Fails with program exit when switch is outside valid range.; Fails with program exit when the direction of any switch was not set to input (e.g. because buttons_init was not called before).

Definition at line 218 of file buttons.c.

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◆ sleep_msec_button_pushed()

int sleep_msec_button_pushed	(	const int	button,
		const int	msec
	)

Check if the given button is pushed in msec milliseconds. The function does NOT return early.

Parameters

button	The button of which the state is monitored.
msec	The number of milliseconds to wait.

Returns: BUTTON_PUSHED or BUTTON_NOT_PUSHED.

Warning: Fails with program exit when button is outside valid range.; Fails with program exit when the direction of the button was not set to input (e.g. because buttons_init was not called before).

Definition at line 110 of file buttons.c.

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◆ sleep_msec_buttons_pushed()

void sleep_msec_buttons_pushed	(	int	button_states[],
		const int	ms
	)

Check if any button is pushed in msec milliseconds. The function does NOT return early.

Parameters

button_states The array of button states that are updated with BUTTON_PUSHED or BUTTON_NOT_PUSHED.

Warning: Fails with program exit when the direction of any button was not set to input (e.g. because buttons_init was not called before).

Definition at line 141 of file buttons.c.

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◆ switches_destroy()

void switches_destroy ( void )

Unitialize the buttons.

Definition at line 65 of file buttons.c.

◆ switches_init()

void switches_init ( void )

Initialise the switches before they can be used.

Definition at line 56 of file buttons.c.

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◆ wait_until_any_button_pushed()

int wait_until_any_button_pushed ( void )

Wait until any button is not pushed (which may be immediately).

Returns: Wait until any button is pushed, return the number of the button that was pushed (0..NUM_BUTTONS-1).

Warning: Fails with program exit when the direction of any button was not set to input (e.g. because buttons_init was not called before).

Definition at line 177 of file buttons.c.

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◆ wait_until_any_button_released()

int wait_until_any_button_released ( void )

Wait until the given button is not pushed (which may be immediately).

Returns: Wait until any button is released, return the number of the button that was pushed (0..NUM_BUTTONS-1).

Warning: Fails with program exit when the direction of any button was not set to input (e.g. because buttons_init was not called before).

Definition at line 198 of file buttons.c.

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◆ wait_until_button_pushed()

int wait_until_button_pushed ( const int button )

Wait until the given button is pushed (which may be immediately).

Parameters

button The button of which the state is monitored.

Returns: The number of milliseconds waited until the button was pushed.

Warning: Fails with program exit when button is outside valid range.; Fails with program exit when the direction of the button was not set to input (e.g. because buttons_init was not called before).

Definition at line 167 of file buttons.c.

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◆ wait_until_button_released()

int wait_until_button_released ( const int button )

Wait until the given button is not pushed (which may be immediately).

Parameters

button The button of which the state is monitored.

Returns: The number of milliseconds waited until the button was released.

Warning: Fails with program exit when button is outside valid range.; Fails with program exit when the direction of the button was not set to input (e.g. because buttons_init was not called before).

Definition at line 172 of file buttons.c.

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◆ wait_until_button_state()

int wait_until_button_state	(	const int	button,
		const int	state
	)

Wait until the given button is in state (which may be immediately).

Parameters

button	The button of which the state is monitored.
state	The state that is waited for. Must be BUTTON_PUSHED or BUTTON_NOT_PUSHED.

Returns: The number of milliseconds that was waited.

Warning: Fails with program exit when button is outside valid range.; Fails with program exit when the direction of the button was not set to input (e.g. because buttons_init was not called before).

Definition at line 84 of file buttons.c.

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Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ BUTTON_NOT_PUSHED

◆ BUTTON_PUSHED

◆ SWITCH_OFF

◆ SWITCH_ON

Enumeration Type Documentation

◆ button_index_t

◆ switches_index_t

Function Documentation

◆ buttons_destroy()

◆ buttons_init()

◆ get_button_state()

◆ get_switch_state()

◆ sleep_msec_button_pushed()

◆ sleep_msec_buttons_pushed()

◆ switches_destroy()

◆ switches_init()

◆ wait_until_any_button_pushed()

◆ wait_until_any_button_released()

◆ wait_until_button_pushed()

◆ wait_until_button_released()

◆ wait_until_button_state()