qdec_driver.c File Reference

The XMEGA Quadrature Decoder driver source file. More...

#include "qdec_driver.h"

Include dependency graph for qdec_driver.c:

Go to the source code of this file.

Functions
bool	QDEC_EVSYS_Setup (uint8_t qEvMux, EVSYS_CHMUX_t qPinInput, bool useIndex, EVSYS_QDIRM_t qIndexState)
	This function configure the event system for quadrature decoding. More...
uint8_t	QDEC_Get_Direction (TC0_t *qTimer)
	This function return the direction of the counter/QDEC. More...
bool	QDEC_Port_Setup (PORT_t *qPort, uint8_t qPin, bool useIndex, bool invIO)
	This function set up the needed configuration for the port used for the quadrature decoding. More...
void	QDEC_TC_Dec_Setup (TC0_t *qTimer, TC_EVSEL_t qEventChannel, uint8_t lineCount)
	This function set up the needed configuration for the Timer/Counter to handle the quadrature decoding from the event system. More...
void	QDEC_TC_Freq_Setup (TC0_t *qTimer, TC_EVSEL_t qEventChannel, EVSYS_CHMUX_t qPinInput, TC_CLKSEL_t clksel)
	This function set up the needed configuration for a Timer/Counter to handle the frequency/speed measurement from the event system. More...
bool	QDEC_Total_Setup (PORT_t *qPort, uint8_t qPin, bool invIO, uint8_t qEvMux, EVSYS_CHMUX_t qPinInput, bool useIndex, EVSYS_QDIRM_t qIndexState, TC0_t *qTimer, TC_EVSEL_t qEventChannel, uint8_t lineCount)
	Wrapperfunction to set up all parameters for the quadrature decoder. More...

Detailed Description

The XMEGA Quadrature Decoder driver source file.

This file contains the function prototypes and enumerator definitions for various configuration parameters for the XMEGA Quadrature Decoder.

The driver is not intended for size and/or speed critical code. The driver is intended for rapid prototyping and documentation purposes for getting started with the XMEGA Quadrature Decoder.

For size and/or speed critical code, it is recommended to copy the function contents directly into your application instead of making a function call.

Several functions use the following construct: "some_register = ... | (some_parameter ? SOME_BIT_bm : 0) | ..." Although the use of the ternary operator ( if ? then : else ) is discouraged, in some occasions the operator makes it possible to write pretty clean and neat code. In this driver, the construct is used to set or not set a configuration bit based on a boolean input parameter, such as the "some_parameter" in the example above.

Application note:

AVR1600: Using the XMEGA Quadrature Decoder

Documentation

For comprehensive code documentation, supported compilers, compiler settings and supported devices see readme.html

Author

Atmel Corporation, now Microchip Technology Inc.: http://www.microchip.com

Revision

7623

Date

2017-09-06 14:57:02 +0200 (on, 06 sep 2017)

Copyright (c) 2012, Atmel Corporation All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
3. The name of ATMEL may not be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Definition in file qdec_driver.c.

Function Documentation

QDEC_EVSYS_Setup()

bool QDEC_EVSYS_Setup	(	uint8_t	qEvMux,
		EVSYS_CHMUX_t	qPinInput,
		bool	useIndex,
		EVSYS_QDIRM_t	qIndexState
	)

This function configure the event system for quadrature decoding.

Parameters

qEvMux	Which event channel to use. Only 0, 2 and 4 is available.
qPinInput	The pin input of QDPH0 to the EVSYS.CHMUX .
useIndex	True if an optional Index pin is used.
qIndexState	In which state the index signal will trigger.

Returns

bool True if setup was ok, false if any errors.

Definition at line 158 of file qdec_driver.c.

Referenced by QDEC_Total_Setup().

{
        switch (qEvMux){
                case 0:
                    
                /* Configure event channel 0 for quadrature decoding of pins. */
                EVSYS.CH0MUX = qPinInput;
                EVSYS.CH0CTRL = EVSYS_QDEN_bm | EVSYS_DIGFILT_2SAMPLES_gc;
                if(useIndex){
                        /*  Configure event channel 1 as index channel. Note
                         *  that when enabling Index in channel n, the channel
                         *  n+1 must be configured for the index signal.*/
                        EVSYS.CH1MUX = qPinInput + 2;
                        EVSYS.CH1CTRL = EVSYS_DIGFILT_2SAMPLES_gc;
                        EVSYS.CH0CTRL |= (uint8_t) qIndexState | EVSYS_QDIEN_bm;

                }
                break;
                case 2:
                EVSYS.CH2MUX = qPinInput;
                EVSYS.CH2CTRL = EVSYS_QDEN_bm | EVSYS_DIGFILT_2SAMPLES_gc;
                if(useIndex){
                        EVSYS.CH3MUX = qPinInput + 2;
                        EVSYS.CH3CTRL = EVSYS_DIGFILT_2SAMPLES_gc;
                        EVSYS.CH2CTRL |= (uint8_t) qIndexState | EVSYS_QDIEN_bm;
                }
                break;
                case 4:
                EVSYS.CH4MUX = qPinInput;
                EVSYS.CH4CTRL = EVSYS_QDEN_bm | EVSYS_DIGFILT_2SAMPLES_gc;
                if(useIndex){
                        EVSYS.CH5MUX = qPinInput + 2;
                        EVSYS.CH5CTRL = EVSYS_DIGFILT_2SAMPLES_gc;
                        EVSYS.CH4CTRL |= (uint8_t) qIndexState | EVSYS_QDIEN_bm;
                }
                break;
                default:
                return false;
        }
        return true;
}

QDEC_Get_Direction()

uint8_t QDEC_Get_Direction

(

TC0_t *

qTimer

)

This function return the direction of the counter/QDEC.

Parameters

qTimer

The timer used for QDEC.

Return values

CW_DIR	if clockwise/up counting,
CCW_DIR	if counter clockwise/down counting.

Definition at line 255 of file qdec_driver.c.

References CCW_DIR, and CW_DIR.

{
        if (qTimer->CTRLFSET & TC0_DIR_bm){
                return CW_DIR;
        }else{
                return CCW_DIR;
        }
}

QDEC_Port_Setup()

bool QDEC_Port_Setup	(	PORT_t *	qPort,
		uint8_t	qPin,
		bool	useIndex,
		bool	invIO
	)

This function set up the needed configuration for the port used for the quadrature decoding.

Parameters

qPort	The port to use.
qPin	The first input pin (QDPH0) to use (0 - 5/6).
useIndex	True if an optional Index pin is used.
invIO	True if IO pins should be inverted.

Returns

bool True if setup was ok, false if any errors.

Definition at line 118 of file qdec_driver.c.

Referenced by QDEC_Total_Setup().

{
        /* Make setup depending on if Index signal is used. */
        if(useIndex){
                if(qPin > 5){
                        return false;
                }
                qPort->DIRCLR = (0x07<<qPin);

                /* Configure Index signal sensing. */
                PORTCFG.MPCMASK = (0x04<<qPin);
                qPort->PIN0CTRL = (qPort->PIN0CTRL & ~PORT_ISC_gm) | PORT_ISC_BOTHEDGES_gc
                                  | (invIO ? PORT_INVEN_bm : 0);


        }else{
                if(qPin > 6){
                        return false;
                }
                qPort->DIRCLR = (0x03<<qPin);
        }

        /* Set QDPH0 and QDPH1 sensing level. */
        PORTCFG.MPCMASK = (0x03<<qPin);
        qPort->PIN0CTRL = (qPort->PIN0CTRL & ~PORT_ISC_gm) | PORT_ISC_LEVEL_gc
                          | (invIO ? PORT_INVEN_bm : 0);

        return true;
}

QDEC_TC_Dec_Setup()

void QDEC_TC_Dec_Setup	(	TC0_t *	qTimer,
		TC_EVSEL_t	qEventChannel,
		uint8_t	lineCount
	)

This function set up the needed configuration for the Timer/Counter to handle the quadrature decoding from the event system.

Parameters

qTimer	The timer to use for QDEC.
qEventChannel	The event channel to listen to.
lineCount	The number of lines in the quadrature encoder.

Definition at line 210 of file qdec_driver.c.

Referenced by QDEC_Total_Setup().

{
        /* Configure TC as a quadrature counter. */
        qTimer->CTRLD = (uint8_t) TC_EVACT_QDEC_gc | qEventChannel;
        qTimer->PER = (lineCount * 4) - 1;
        qTimer->CTRLA = TC_CLKSEL_DIV1_gc;
}

QDEC_TC_Freq_Setup()

void QDEC_TC_Freq_Setup	(	TC0_t *	qTimer,
		TC_EVSEL_t	qEventChannel,
		EVSYS_CHMUX_t	qPinInput,
		TC_CLKSEL_t	clksel
	)

This function set up the needed configuration for a Timer/Counter to handle the frequency/speed measurement from the event system.

Note

The real frequency of rotation can be calculated from the capture register by using the folowing function. FREQ = ( F_CPU / clk_div ) / ( CAPTURE * lineCount )

Parameters

qTimer	The timer to use for QDEC.
qEventChannel	The event channel to listen to.
qPinInput	The pin input of QDPH0 to the EVSYS.CHMUX.
clksel	The clk div to use for timer.

Definition at line 231 of file qdec_driver.c.

Referenced by main().

{
        /* Configure channel 2 to input pin for freq calculation. */
        EVSYS.CH2MUX = qPinInput;
        EVSYS.CH2CTRL = EVSYS_DIGFILT_4SAMPLES_gc;

        /* Configure TC to capture frequency. */
        qTimer->CTRLD = (uint8_t) TC_EVACT_FRQ_gc | qEventChannel;
        qTimer->PER = 0xFFFF;
        qTimer->CTRLB = TC0_CCAEN_bm;
        qTimer->CTRLA = clksel;
}

QDEC_Total_Setup()

bool QDEC_Total_Setup	(	PORT_t *	qPort,
		uint8_t	qPin,
		bool	invIO,
		uint8_t	qEvMux,
		EVSYS_CHMUX_t	qPinInput,
		bool	useIndex,
		EVSYS_QDIRM_t	qIndexState,
		TC0_t *	qTimer,
		TC_EVSEL_t	qEventChannel,
		uint8_t	lineCount
	)

Wrapperfunction to set up all parameters for the quadrature decoder.

This function combines the following functions for a total setup: QDEC_Port_Setup, QDEC_EVSYS_Setup and QDEC_TC_Dec_Setup.

Parameters

qPort	The port to use.
qPin	The first input pin (QDPH0) to use (0 - 5/6).
invIO	True if IO pins should be inverted.
qEvMux	Which event channel to use. Only 0, 2 and 4 is available.
qPinInput	The pin input of QDPH0 to the EVSYS.CHMUX .
useIndex	True if an optional Index pin is used.
qIndexState	In which state the index signal will trigger.
qTimer	The timer to use for QDEC.
qEventChannel	The event channel to listen to.
lineCount	The number of lines in the quadrature encoder.

Returns

bool True if setup was ok, false if any errors.

Definition at line 87 of file qdec_driver.c.

References QDEC_EVSYS_Setup(), QDEC_Port_Setup(), and QDEC_TC_Dec_Setup().

Referenced by main().

{
        if( !QDEC_Port_Setup(qPort, qPin, useIndex, invIO) )
                return false;
        if( !QDEC_EVSYS_Setup(qEvMux, qPinInput, useIndex, qIndexState ) )
                return false;
        QDEC_TC_Dec_Setup(qTimer, qEventChannel, lineCount);

        return true;
}

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