QEI

Quadrature Encoder Interface. More...

Collaboration diagram for QEI:

Data Structures
struct	qei_data_t
struct	qei_channel_attr_t
struct	qei_handle_t

Typedefs
typedef void(*	hal_qei_callback) (const uint8_t channel, const uint8_t flag)
	Index interrupt callback function prototype.

Enumerations
enum	qei_result_t {   QEI_RESULT_OK ,   QEI_RESULT_INVALID ,   QEI_RESULT_UNSUPPORTED ,   QEI_RESULT_ERR ,   TOTAL_QEI_RESULT }
enum	qei_status_t {   QEI_STATUS_UNKNOWN ,   QEI_STATUS_OK ,   QEI_STATUS_BUSY ,   QEI_STATUS_STOP ,   QEI_STATUS_ERR ,   TOTAL_QEI_STATUS }
enum	qei_reset_mode_t {   QEI_RESET_MODE_NONE ,   QEI_RESET_MODE_HOME_EVENT ,   QEI_RESET_MODE_INDEX_EVENT ,   TOTAL_QEI_RESET_MODE }
enum	qei_direction_t {   QEI_DIRECTION_NONE ,   QEI_DIRECTION_FORWARD ,   QEI_DIRECTION_REVERSE ,   TOTAL_QEI_DIRECTION }
enum	qei_interrupt_t {   QEI_INTERRUPT_HOME ,   QEI_INTERRUPT_INDEX ,   QEI_INTERRUPT_OVERFLOW ,   QEI_INTERRUPT_LOWER_LIMIT ,   QEI_INTERRUPT_UPPER_LIMIT ,   TOTAL_QEI_INTERRUPT }

Functions
qei_result_t	hal_qei_init (qei_handle_t *handle, const qei_channel_attr_t attr, const hal_qei_callback callback)
	Configure QEI channel.
int32_t	hal_qei_get_counter (qei_handle_t *handle)
	Get encoder counter value.
qei_result_t	hal_qei_set_counter (qei_handle_t *handle, const int32_t value)
	Set encoder counter to specified value.
qei_result_t	hal_qei_reset_counter (qei_handle_t *handle)
	Reset encoder counter value to zero.
qei_result_t	hal_qei_start (qei_handle_t *handle)
	Enable QEI channel.
qei_result_t	hal_qei_stop (qei_handle_t *handle)
	Disable QEI channel.

Detailed Description

Quadrature Encoder Interface.

Typedef Documentation

hal_qei_callback

typedef void(* hal_qei_callback) (const uint8_t channel, const uint8_t flag)

#include <qei/public_inc/hal_qei.h>

Index interrupt callback function prototype.

Parameters

[in]	channel	QEI channel
[in]	flag	QEI interrupt flag

Enumeration Type Documentation

qei_direction_t

enum qei_direction_t

#include <qei/public_inc/hal_qei.h>

Enumerator
QEI_DIRECTION_NONE
QEI_DIRECTION_FORWARD
QEI_DIRECTION_REVERSE
TOTAL_QEI_DIRECTION

qei_interrupt_t

enum qei_interrupt_t

#include <qei/public_inc/hal_qei.h>

Enumerator
QEI_INTERRUPT_HOME
QEI_INTERRUPT_INDEX
QEI_INTERRUPT_OVERFLOW
QEI_INTERRUPT_LOWER_LIMIT
QEI_INTERRUPT_UPPER_LIMIT
TOTAL_QEI_INTERRUPT

qei_reset_mode_t

enum qei_reset_mode_t

#include <qei/public_inc/hal_qei.h>

Enumerator
QEI_RESET_MODE_NONE
QEI_RESET_MODE_HOME_EVENT
QEI_RESET_MODE_INDEX_EVENT
TOTAL_QEI_RESET_MODE

qei_result_t

enum qei_result_t

#include <qei/public_inc/hal_qei.h>

Enumerator
QEI_RESULT_OK	No error.
QEI_RESULT_INVALID	Operation invalid.
QEI_RESULT_UNSUPPORTED	Operation not supported.
QEI_RESULT_ERR	Error occurred.
TOTAL_QEI_RESULT

qei_status_t

enum qei_status_t

#include <qei/public_inc/hal_qei.h>

Enumerator
QEI_STATUS_UNKNOWN	Unknown channel status.
QEI_STATUS_OK	No error.
QEI_STATUS_BUSY	Channel busy.
QEI_STATUS_STOP	Channel stopped.
QEI_STATUS_ERR	Error occurred.
TOTAL_QEI_STATUS

Function Documentation

hal_qei_get_counter()

int32_t hal_qei_get_counter

(

qei_handle_t *

handle

)

#include <qei/public_inc/hal_qei.h>

Get encoder counter value.

If counter value reached INT32_MAX value either positive or negative signed, counter will reset value to zero.

int32_t counter = hal_qei_get_counter( &handle );

Parameters

[in,out]

handle

QEI handler

Returns

Encoder counter value

hal_qei_init()

qei_result_t hal_qei_init	(	qei_handle_t *	handle,
		const qei_channel_attr_t	attr,
		const hal_qei_callback	callback )

#include <qei/public_inc/hal_qei.h>

Configure QEI channel.

static void callback( const uint8_t channel );
 
qei_handle_t handle = {
    .channel = BSP_QEI_CHANNEL_1
};
 
qei_channel_attr_t attr = {
    .ch_a_pin    = CHANNEL_A_PIN,
    .ch_b_pin    = CHANNEL_B_PIN,
    .index_pin   = INDEX_PIN,
    .start_value = 0,
    .reset_mode  = QEI_RESET_MODE_INDEX_EVENT
};
 
qei_result_t result = hal_qei_init( &handle, attr, &callback );

Parameters

[in,out]	handle	QEI handler
[in]	attr	QEI channel attributes

Return values

QEI_RESULT_OK	Success configure QEI channel
QEI_RESULT_INVALID	Configuration attributes invalid
QEI_RESULT_UNSUPPORTED	Operation not supported
QEI_RESULT_ERR	Failed configure QEI channel

hal_qei_reset_counter()

qei_result_t hal_qei_reset_counter

(

qei_handle_t *

handle

)

#include <qei/public_inc/hal_qei.h>

Reset encoder counter value to zero.

hal_qei_reset( &handle );
 
int32_t counter = hal_qei_reset_counter( &handle );
assert( counter == 0 );

Parameters

[in,out]

handle

QEI handler

Return values

QEI_RESULT_OK	Success reset counter to zero
QEI_RESULT_INVALID	Configuration attributes invalid
QEI_RESULT_UNSUPPORTED	Operation not supported
QEI_RESULT_ERR	Failed to reset counter

hal_qei_set_counter()

qei_result_t hal_qei_set_counter	(	qei_handle_t *	handle,
		const int32_t	value )

#include <qei/public_inc/hal_qei.h>

Set encoder counter to specified value.

hal_qei_set_counter( &handle, -500 );
 
int32_t counter = hal_qei_get_counter( &handle );
assert( counter == -500 );

Parameters

[in,out]	handle	QEI handler
[in]	value	Counter value to be loaded

Return values

QEI_RESULT_OK	Success load counter value
QEI_RESULT_INVALID	Invalid counter value
QEI_RESULT_UNSUPPORTED	Operation not supported
QEI_RESULT_ERR	Failed to load counter value

hal_qei_start()

qei_result_t hal_qei_start

(

qei_handle_t *

handle

)

#include <qei/public_inc/hal_qei.h>

Enable QEI channel.

qei_result_t result = hal_qei_start( &handle );

Parameters

[in,out]

handle

QEI handler

Return values

QEI_RESULT_OK	Success start QEI channel
QEI_RESULT_UNSUPPORTED	Operation not supported
QEI_RESULT_ERR	Failed to start QEI channel

hal_qei_stop()

qei_result_t hal_qei_stop

(

qei_handle_t *

handle

)

#include <qei/public_inc/hal_qei.h>

Disable QEI channel.

qei_result_t result = hal_qei_stop( &handle );

Parameters

[in,out]

handle

QEI handler

Return values

QEI_RESULT_OK	Success stop QEI channel
QEI_RESULT_UNSUPPORTED	Operation not supported
QEI_RESULT_ERR	Failed to stop QEI channel