Joystick API#

Joystick API.

Introduction#

The joystick driver is a platform board level software module that provides the functionality to initialize and read joystick position through the joystick hardware present on the Wireless Pro Kit (BRD4002A)

Configuration#

Joystick driver allows configuring the rate of signal acquisition. This can be configured from the joystick component, available options are:

100 samples/second
1000 samples/second
5000 samples/second
10000 samples/second
25000 samples/second

Joystick driver also allows configuring the voltage values which correspond to a particular joystick position

Usage#

Once the joystick handle of type sl_joystick_t is defined, joystick functions can be called being passed the defined handle. The functions include the following:

sl_joystick_init must be called followed by sl_joystick_start before attempting to read the position of the joystick.

The sl_joystick_get_position is used to update the position, and needs to be called from a tick function or similar by the user.

Basic example code to show usage of Joystick driver

#include "sl_joystick.h"

sl_joystick_t sl_joystick_handle = JOYSTICK_HANDLE_DEFAULT

int main( void )
{
   // Initialize driver
   sl_joystick_init(&sl_joystick_handle);

   // Start acquiring joystick signal
   sl_joystick_start(&sl_joystick_handle);

   sl_joystick_position_t pos;

   while (1) {

   sl_joystick_get_position(&sl_joystick_handle, &pos);

   ...

   }
}

Modules#

sl_joystick

Direction Enums#

DATA TYPES *********************************

enum

sl_joystick_position_t {

JOYSTICK_NONE = 0u

JOYSTICK_C

JOYSTICK_N

JOYSTICK_E

JOYSTICK_S

JOYSTICK_W

}

enum for finding the position of Joystick.

Enumerations#

enum

sl_joystick_state_t {

SL_JOYSTICK_DISABLED = 0U

SL_JOYSTICK_ENABLED = 1U

}

Joystick state (ENABLE / DISABLE) enum.

Typedefs#

typedef sl_joystick

sl_joystick_t

sl_joystick_t is the alias name of sl_joystick.

Functions#

sl_status_t

sl_joystick_init(sl_joystick_t *joystick_handle)

PROTOTYPES **********************************.

sl_status_t

sl_joystick_get_position(sl_joystick_t *joystick_handle, sl_joystick_position_t *pos)

Get joystick position.

void

sl_joystick_start(sl_joystick_t *joystick_handle)

Start Analog Joystick data acquisition.

void

sl_joystick_stop(sl_joystick_t *joystick_handle)

Stop Analog Joystick data acquisition.

Macros#

#define

ENABLE_SECONDARY_DIRECTIONS 0

DEFINES ************************************.

#define

CLK_SRC_ADC_FREQ 5000000

MACROS to Set CLK_SRC_ADC_FREQ and CLK_ADC_FREQ.

#define

CLK_ADC_FREQ 1000000

A MACRO for clock ADC, clock ADC frequency is 1 MHz.

#define

JOYSTICK_HANDLE_DEFAULT undefined

Default Joystick handle structure.

Direction Enums Documentation#

sl_joystick_position_t#

sl_joystick_position_t

enum for finding the position of Joystick.

Enumerator
JOYSTICK_NONE	Not pressed.
JOYSTICK_C	Center.
JOYSTICK_N	North.
JOYSTICK_E	East.
JOYSTICK_S	South.
JOYSTICK_W	West.

Definition at line 88 of file hardware/driver/joystick/inc/sl_joystick.h

Enumeration Documentation#

sl_joystick_state_t#

sl_joystick_state_t

Joystick state (ENABLE / DISABLE) enum.

Enumerator
SL_JOYSTICK_DISABLED	Analog Joystick data acquisition is disabled.
SL_JOYSTICK_ENABLED	Analog Joystick data acquisition is enabled.

Definition at line 106 of file hardware/driver/joystick/inc/sl_joystick.h

Typedef Documentation#

sl_joystick_t#

typedef sl_joystick sl_joystick_t

sl_joystick_t is the alias name of sl_joystick.

Definition at line 119 of file hardware/driver/joystick/inc/sl_joystick.h

Function Documentation#

sl_joystick_init#

sl_status_t sl_joystick_init (sl_joystick_t * joystick_handle)

PROTOTYPES **********************************.

Parameters

[in]

joystick_handle

Pointer to joystick handle

Joystick init. This function should be called before calling any other Joystick function. Sets up the ADC.

Returns

Status Code:
- SL_STATUS_OK Success
- SL_STATUS_ALLOCATION_FAILED Bus Allocation error

Definition at line 135 of file hardware/driver/joystick/inc/sl_joystick.h

sl_joystick_get_position#

sl_status_t sl_joystick_get_position (sl_joystick_t * joystick_handle, sl_joystick_position_t * pos)

Get joystick position.

Parameters

[in]	joystick_handle	Pointer to joystick handle
[out]	pos	Pointer to output variable of type sl_joystick_position_t

Returns

Status Code:
- SL_STATUS_OK Success
- SL_STATUS_NOT_READY Joystick acquition not started error

Definition at line 149 of file hardware/driver/joystick/inc/sl_joystick.h

sl_joystick_start#

void sl_joystick_start (sl_joystick_t * joystick_handle)

Start Analog Joystick data acquisition.

Parameters

[in]

joystick_handle

Pointer to joystick handle

Definition at line 157 of file hardware/driver/joystick/inc/sl_joystick.h

sl_joystick_stop#

void sl_joystick_stop (sl_joystick_t * joystick_handle)

Stop Analog Joystick data acquisition.

Parameters

[in]

joystick_handle

Pointer to joystick handle

Definition at line 165 of file hardware/driver/joystick/inc/sl_joystick.h

Macro Definition Documentation#

ENABLE_SECONDARY_DIRECTIONS#

#define ENABLE_SECONDARY_DIRECTIONS

Value:

DEFINES ************************************.

Definition at line 56 of file hardware/driver/joystick/inc/sl_joystick.h

CLK_SRC_ADC_FREQ#

#define CLK_SRC_ADC_FREQ

Value:

MACROS to Set CLK_SRC_ADC_FREQ and CLK_ADC_FREQ.

A MACRO for clock source ADC frequency, clock source ADC frequency is 5MHZ.

Definition at line 68 of file hardware/driver/joystick/inc/sl_joystick.h

CLK_ADC_FREQ#

#define CLK_ADC_FREQ

Value:

A MACRO for clock ADC, clock ADC frequency is 1 MHz.

Definition at line 69 of file hardware/driver/joystick/inc/sl_joystick.h

JOYSTICK_HANDLE_DEFAULT#

#define JOYSTICK_HANDLE_DEFAULT

Value:

{ \

SL_JOYSTICK_PORT, /*Joystick gpio port*/ \

SL_JOYSTICK_PIN, /*Joystick gpio pin*/ \

SL_JOYSTICK_DISABLED, /*Joystick signal acquisition not start*/ \

}

Default Joystick handle structure.

Default Joystick handle structure

Definition at line 72 of file hardware/driver/joystick/inc/sl_joystick.h