2.22 QEI Driver

2.22.1 Introduction

Overview

The Quadrature Encoder Interface (QEI) provides the interface to incremental encoders for obtaining mechanical position data. Detects position and speed of rotating motion systems.

Features

  • Configurable QEI operation mode.
  • Configurable Digital noise filter clock frequency.
  • Configurable Index and Home pulse polarity.
  • QEI input clock prescalar value is user configurable in the Hardware Dependency module (PLIB).

2.22.2 Module Documentation

2.22.2.1 QEI Driver

The Quadrature Encoder Interface (QEI) driver provides the interface to incremental encoders for obtaining mechanical position data and Also Detects position and speed of rotating motion systems using dsPIC MCUs.

2.22.2.1.1 Module description

The Quadrature Encoder Interface (QEI) driver provides the interface to incremental encoders for obtaining mechanical position data and Also Detects position and speed of rotating motion systems using dsPIC MCUs.

2.22.2.1.1.1 Data structures

  • struct QEI_INTERFACE

    Structure containing the function pointers of QEI driver.

2.22.2.1.1.3 Functions

  • static void QEI1_Disable (void)

    This inline function disables the QEI1 module.

  • static void QEI1_Enable (void)

    This inline function enables the QEI1 module.

  • static uint32_t QEI1_PositionCountRead (void)

    This inline function returns the 32-bit position count value.

  • static uint16_t QEI1_PositionCount16bitRead (void)

    This inline function returns the 16-bit position count value from the QEI1 position count register.

  • static void QEI1_PositionCountWrite (uint32_t positionCount)

    This inline function sets the QEI1 position count value.

  • static void QEI1_ModuloRangeSet (uint32_t countsPerRevolution)

    This inline function sets the 32bit modulo count value when QEI is configured to operate in 'Modulo Count' mode. The lower bound controlled by the QEILEC register is set to 0.

  • static bool QEI1_PhaseInputSwappedGet (void)

    This inline function gets the status of QEI input phase swap configuration.

  • static void QEI1_PhaseInputSwappedSet (bool swapEnabled)

    This inline function sets whether the QEA and QEB pins are swapped prior to quadrature decoder logic.

  • static void QEI1_PositionCaptureEnable (void)

    This inline function enables the QEI position count capture on an index event.

  • static void QEI1_PositionCaptureDisable (void)

    This inline function disables the QEI position count capture on an index event.

  • static uint32_t QEI1_PositionCaptureGet (void)

    This inline function reads the 32-bit position capture value from the QEIICx 32 bit register.

  • static uint16_t QEI1_PositionCapture16bitGet (void)

    This inline function returns the 16-bit position capture value from QEIICL position count capture register.

  • static void QEI1_PositionCaptureSet (uint32_t initValue)

    This inline function initializes the 32 bit position capture register value.

  • static void QEI1_CounterModeSet (enum QEI_MODE mode)

    This inline function sets the QEI Counter mode.

  • static void QEI1_IMVGatedValueSet (enum QEI_IMV_STATE state)

    This inline function sets the QEI Index Match Value.

  • void QEI1_Initialize (void)

    Initializes the QEI module.

  • void QEI1_Deinitialize (void)

    Deinitializes the QEI1 to POR values.

2.22.2.1.1.4 Variables

2.22.2.1.2 Function Documentation

2.22.2.1.2.1 QEI1_CounterModeSet()

static void QEI1_CounterModeSet (enum QEI_MODE mode)[inline], [static]

This inline function sets the QEI Counter mode.

Parameters:
in mode

- Sets the QEI counter mode

Returns:

none

2.22.2.1.2.2 QEI1_Deinitialize()

void QEI1_Deinitialize (void )

Deinitializes the QEI1 to POR values.

Parameters:
none
Returns:

none

2.22.2.1.2.3 QEI1_Disable()

static void QEI1_Disable (void )[inline], [static]

This inline function disables the QEI1 module.

Parameters:
none
Returns:

none

2.22.2.1.2.4 QEI1_Enable()

static void QEI1_Enable (void )[inline], [static]

This inline function enables the QEI1 module.

Parameters:
none
Returns:

none

2.22.2.1.2.5 QEI1_IMVGatedValueSet()

static void QEI1_IMVGatedValueSet (enum QEI_IMV_STATE state)[inline], [static]

This inline function sets the QEI Index Match Value.

Parameters:
in mode

- Sets the QEI Index Match Value

Returns:

none

2.22.2.1.2.6 QEI1_Initialize()

void QEI1_Initialize (void )

Initializes the QEI module.

Parameters:
none
Returns:

none

2.22.2.1.2.7 QEI1_ModuloRangeSet()

static void QEI1_ModuloRangeSet (uint32_t countsPerRevolution)[inline], [static]

This inline function sets the 32bit modulo count value when QEI is configured to operate in 'Modulo Count' mode. The lower bound controlled by the QEILEC register is set to 0.

Parameters:
in countsPerRevolution

- Modulus number of counts per wraparound

Returns:

none

2.22.2.1.2.8 QEI1_PhaseInputSwappedGet()

static bool QEI1_PhaseInputSwappedGet (void )[inline], [static]

This inline function gets the status of QEI input phase swap configuration.

Parameters:
none
Returns:

true - Phase inputs are swapped

false - Phase inputs are not swapped

2.22.2.1.2.9 QEI1_PhaseInputSwappedSet()

static void QEI1_PhaseInputSwappedSet (bool swapEnabled)[inline], [static]

This inline function sets whether the QEA and QEB pins are swapped prior to quadrature decoder logic.

Parameters:
in swapEnabled

- specifies whether QEA and QEB pins need to be swapped prior to quadrature decoder logic

Returns:

none

2.22.2.1.2.10 QEI1_PositionCapture16bitGet()

static uint16_t QEI1_PositionCapture16bitGet (void )[inline], [static]

This inline function returns the 16-bit position capture value from QEIICL position count capture register.

Parameters:
none
Returns:

Returns the LSB 16 bits of position capture value

2.22.2.1.2.11 QEI1_PositionCaptureDisable()

static void QEI1_PositionCaptureDisable (void )[inline], [static]

This inline function disables the QEI position count capture on an index event.

Parameters:
none
Returns:

none

2.22.2.1.2.12 QEI1_PositionCaptureEnable()

static void QEI1_PositionCaptureEnable (void )[inline], [static]

This inline function enables the QEI position count capture on an index event.

Parameters:
none
Returns:

none

2.22.2.1.2.13 QEI1_PositionCaptureGet()

static uint32_t QEI1_PositionCaptureGet (void )[inline], [static]

This inline function reads the 32-bit position capture value from the QEIICx 32 bit register.

Parameters:
none
Returns:

Returns position capture value

2.22.2.1.2.14 QEI1_PositionCaptureSet()

static void QEI1_PositionCaptureSet (uint32_t initValue)[inline], [static]

This inline function initializes the 32 bit position capture register value.

Parameters:
in initValue

- 32 bit position capture register value

Returns:

none

2.22.2.1.2.15 QEI1_PositionCount16bitRead()

static uint16_t QEI1_PositionCount16bitRead (void )[inline], [static]

This inline function returns the 16-bit position count value from the QEI1 position count register.

Parameters:
none
Returns:

Returns the LSB 16 bits of the QEI1 position count register.

2.22.2.1.2.16 QEI1_PositionCountRead()

static uint32_t QEI1_PositionCountRead (void )[inline], [static]

This inline function returns the 32-bit position count value.

Parameters:
none
Returns:

Returns the 32-bit position count register value

2.22.2.1.2.17 QEI1_PositionCountWrite()

static void QEI1_PositionCountWrite (uint32_t positionCount)[inline], [static]

This inline function sets the QEI1 position count value.

Parameters:
in positionCount

- 32-bit position count value

Returns:

none

2.22.2.1.3 Enumeration Type Documentation

2.22.2.1.3.1 QEI_IMV_STATE

enum QEI_IMV_STATE

Defines the QEI Index Match Value states.

QEI_IMV_STATE_A0B0

Index Match Value State : QEA = 0 and QEB = 0

QEI_IMV_STATE_A1B0

Index Match Value State : QEA = 1 and QEB = 0

QEI_IMV_STATE_A0B1

Index Match Value State : QEA = 0 and QEB = 1

QEI_IMV_STATE_A1B1

Index Match Value State : QEA = 1 and QEB = 1

QEI_MAX_IMV_STATE

Maximum configurable Index Match Value State

2.22.2.1.3.2 QEI_MODE

enum QEI_MODE

Defines the QEI operating mode.

QEI_MODE_FREE_RUNNING

Index input event does not affect position counter

QEI_MODE_RESET_ON_INDEX

Every index input event resets the position counter

QEI_MODE_2

Next index input event initializes the position counter with contents of QEI1IC register

QEI_MODE_3

First index event after home event initializes position counter with contents of QEI1IC register

QEI_MODE_4

Second index event after home event initializes position counter with contents of QEI1IC register

QEI_MODE_5

Resets the position counter when the position counter equals QEI1GEC register

QEI_MODE_MODULO_COUNT

Modulo Count mode for position counter

2.22.2.1.4 Variable Documentation

2.22.2.1.4.1 QEI1

const struct QEI_INTERFACE QEI1

Structure object of type QEI_INTERFACE with the custom name given by the user in the Melody Driver User interface.

The default name e.g. QEI1 can be changed by the user in the QEI user interface. This allows defining a structure with application specific name using the 'Custom Name' field. Application specific name allows the API Portability.

2.22.3 Class Documentation

2.22.3.1 QEI_INTERFACE Struct Reference

Structure containing the function pointers of QEI driver.

2.22.3.1.1 Detailed Description

Structure containing the function pointers of QEI driver.

#include <qei_interface.h>

2.22.3.1.1.1 Public Attributes

2.22.3.1.2 Member Data Documentation

The documentation for this struct was generated from the following file:

source/

qei_interface.h

2.22.3.1.2.1 CounterModeSet

void(* CounterModeSet) (enum QEI_MODE mode)

Pointer to QEIx_CounterModeSet e.g. QEI1_CounterModeSet.

2.22.3.1.2.2 Deinitialize

void(* Deinitialize) (void)

Pointer to QEIx_Deinitialize e.g. QEI1_Deinitialize.

2.22.3.1.2.3 Disable

void(* Disable) (void)

Pointer to QEIx_Disable e.g. QEI1_Disable.

2.22.3.1.2.4 Enable

void(* Enable) (void)

Pointer to QEIx_Enable e.g. QEI1_Enable.

2.22.3.1.2.5 IMVGatedValueSet

void(* IMVGatedValueSet) (enum QEI_IMV_STATE state)

Pointer to QEIx_IMVGatedValueSet e.g. QEI1_IMVGatedValueSet.

2.22.3.1.2.6 Initialize

void(* Initialize) (void)

Pointer to QEIx_Initialize e.g. QEI1_Initialize.

2.22.3.1.2.7 ModuloRangeSet

void(* ModuloRangeSet) (uint32_t countsPerRevolution)

Pointer to QEIx_ModuloRangeSet e.g. QEI1_ModuloRangeSet.

2.22.3.1.2.8 PhaseInputSwappedGet

bool(* PhaseInputSwappedGet) (void)

Pointer to QEIx_PhaseInputSwappedGet e.g. QEI1_PhaseInputSwappedGet.

2.22.3.1.2.9 PhaseInputSwappedSet

void(* PhaseInputSwappedSet) (bool swapEnabled)

Pointer to QEIx_PhaseInputSwappedSet e.g. QEI1_PhaseInputSwappedSet.

2.22.3.1.2.10 PositionCapture16bitGet

uint16_t(* PositionCapture16bitGet) (void)

Pointer to QEIx_PositionCapture16bitGet e.g. QEI1_PositionCapture16bitGet.

2.22.3.1.2.11 PositionCaptureDisable

void(* PositionCaptureDisable) (void)

Pointer to QEIx_PositionCaptureDisable e.g. QEI1_PositionCaptureDisable.

2.22.3.1.2.12 PositionCaptureEnable

void(* PositionCaptureEnable) (void)

Pointer to QEIx_PositionCaptureEnable e.g. QEI1_PositionCaptureEnable.

2.22.3.1.2.13 PositionCaptureGet

uint32_t(* PositionCaptureGet) (void)

Pointer to QEIx_PositionCaptureGet e.g. QEI1_PositionCaptureGet.

2.22.3.1.2.14 PositionCaptureSet

void(* PositionCaptureSet) (uint32_t initValue)

Pointer to QEIx_PositionCaptureSet e.g. QEI1_PositionCaptureSet.

2.22.3.1.2.15 PositionCount16bitRead

uint16_t(* PositionCount16bitRead) (void)

Pointer to QEIx_PositionCount16bitRead e.g. QEI1_PositionCount16bitRead.

2.22.3.1.2.16 PositionCountRead

uint32_t(* PositionCountRead) (void)

Pointer to QEIx_PositionCountRead e.g. QEI1_PositionCountRead.

2.22.3.1.2.17 PositionCountWrite

void(* PositionCountWrite) (uint32_t positionCount)

Pointer to QEIx_PositionCountWrite e.g. QEI1_PositionCountWrite.

2.22.4 File Documentation

2.22.4.1 source/qei1.h File Reference

This is the generated driver header file for the QEI1 driver. 

#include <xc.h>
#include <stdbool.h>
#include <stdint.h>
#include "qei_types.h"
#include "qei_interface.h"

2.22.4.1.1 Functions

  • static void QEI1_Disable (void)

    This inline function disables the QEI1 module.

  • static void QEI1_Enable (void)

    This inline function enables the QEI1 module.

  • static uint32_t QEI1_PositionCountRead (void)

    This inline function returns the 32-bit position count value.

  • static uint16_t QEI1_PositionCount16bitRead (void)

    This inline function returns the 16-bit position count value from the QEI1 position count register.

  • static void QEI1_PositionCountWrite (uint32_t positionCount)

    This inline function sets the QEI1 position count value.

  • static void QEI1_ModuloRangeSet (uint32_t countsPerRevolution)

    This inline function sets the 32bit modulo count value when QEI is configured to operate in 'Modulo Count' mode. The lower bound controlled by the QEILEC register is set to 0.

  • static bool QEI1_PhaseInputSwappedGet (void)

    This inline function gets the status of QEI input phase swap configuration.

  • static void QEI1_PhaseInputSwappedSet (bool swapEnabled)

    This inline function sets whether the QEA and QEB pins are swapped prior to quadrature decoder logic.

  • static void QEI1_PositionCaptureEnable (void)

    This inline function enables the QEI position count capture on an index event.

  • static void QEI1_PositionCaptureDisable (void)

    This inline function disables the QEI position count capture on an index event.

  • static uint32_t QEI1_PositionCaptureGet (void)

    This inline function reads the 32-bit position capture value from the QEIICx 32 bit register.

  • static uint16_t QEI1_PositionCapture16bitGet (void)

    This inline function returns the 16-bit position capture value from QEIICL position count capture register.

  • static void QEI1_PositionCaptureSet (uint32_t initValue)

    This inline function initializes the 32 bit position capture register value.

  • static void QEI1_CounterModeSet (enum QEI_MODE mode)

    This inline function sets the QEI Counter mode.

  • static void QEI1_IMVGatedValueSet (enum QEI_IMV_STATE state)

    This inline function sets the QEI Index Match Value.

  • void QEI1_Initialize (void)

    Initializes the QEI module.

  • void QEI1_Deinitialize (void)

    Deinitializes the QEI1 to POR values.

2.22.4.1.2 Variables

2.22.4.1.3 Detailed Description

This is the generated driver header file for the QEI1 driver.

QEI1 Generated Driver Header File

2.22.4.2 source/qei_interface.h File Reference

#include <stdbool.h>
#include <stdint.h>
#include "qei_types.h"

2.22.4.2.1 Data structures

  • struct QEI_INTERFACE

    Structure containing the function pointers of QEI driver.

2.22.4.2.2 Detailed Description

QEI Generated Driver Interface Header File

2.22.4.3 source/qei_types.h File Reference

This is the generated driver types header file for the QEI driver.

2.22.4.3.2 Detailed Description

This is the generated driver types header file for the QEI driver.

QEI Generated Driver Types Header File