/*! \file encoder.c \brief Quadrature Encoder reader/driver. */
//*****************************************************************************
//
// File Name : 'encoder.c'
// Title : Quadrature Encoder reader/driver
// Author : Pascal Stang - Copyright (C) 2003-2004
// Created : 2003.01.26
// Revised : 2004.06.25
// Version : 0.3
// Target MCU : Atmel AVR Series
// Editor Tabs : 4
//
// NOTE: This code is currently below version 1.0, and therefore is considered
// to be lacking in some functionality or documentation, or may not be fully
// tested. Nonetheless, you can expect most functions to work.
//
// This code is distributed under the GNU Public License
// which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************
#include <avr/io.h>
#include <avr/interrupt.h>
#include "global.h"
#include "encoder.h"
// Program ROM constants
// Global variables
volatile EncoderStateType EncoderState[NUM_ENCODERS];
// Functions
// encoderInit() initializes hardware and encoder position readings
// Run this init routine once before using any other encoder functions.
void encoderInit(void)
{
u08 i;
// initialize/clear encoder data
for(i=0; i<NUM_ENCODERS; i++)
{
EncoderState[i].position = 0;
//EncoderState[i].velocity = 0; // NOT CURRENTLY USED
}
// configure direction and interrupt I/O pins:
// - for input
// - apply pullup resistors
// - any-edge interrupt triggering
// - enable interrupt
#ifdef ENC0_SIGNAL
// set interrupt pins to input and apply pullup resistor
cbi(ENC0_PHASEA_DDR, ENC0_PHASEA_PIN);
sbi(ENC0_PHASEA_PORT, ENC0_PHASEA_PIN);
// set encoder direction pin for input and apply pullup resistor
cbi(ENC0_PHASEB_DDR, ENC0_PHASEB_PIN);
sbi(ENC0_PHASEB_PORT, ENC0_PHASEB_PIN);
// configure interrupts for any-edge triggering
sbi(ENC0_ICR, ENC0_ISCX0);
cbi(ENC0_ICR, ENC0_ISCX1);
// enable interrupts
sbi(IMSK, ENC0_INT); // ISMK is auto-defined in encoder.h
#endif
#ifdef ENC1_SIGNAL
// set interrupt pins to input and apply pullup resistor
cbi(ENC1_PHASEA_DDR, ENC1_PHASEA_PIN);
sbi(ENC1_PHASEA_PORT, ENC1_PHASEA_PIN);
// set encoder direction pin for input and apply pullup resistor
cbi(ENC1_PHASEB_DDR, ENC1_PHASEB_PIN);
sbi(ENC1_PHASEB_PORT, ENC1_PHASEB_PIN);
// configure interrupts for any-edge triggering
sbi(ENC1_ICR, ENC1_ISCX0);
cbi(ENC1_ICR, ENC1_ISCX1);
// enable interrupts
sbi(IMSK, ENC1_INT); // ISMK is auto-defined in encoder.h
#endif
#ifdef ENC2_SIGNAL
// set interrupt pins to input and apply pullup resistor
cbi(ENC2_PHASEA_DDR, ENC2_PHASEA_PIN);
sbi(ENC2_PHASEA_PORT, ENC2_PHASEA_PIN);
// set encoder direction pin for input and apply pullup resistor
cbi(ENC2_PHASEB_DDR, ENC2_PHASEB_PIN);
sbi(ENC2_PHASEB_PORT, ENC2_PHASEB_PIN);
// configure interrupts for any-edge triggering
sbi(ENC2_ICR, ENC2_ISCX0);
cbi(ENC2_ICR, ENC2_ISCX1);
// enable interrupts
sbi(IMSK, ENC2_INT); // ISMK is auto-defined in encoder.h
#endif
#ifdef ENC3_SIGNAL
// set interrupt pins to input and apply pullup resistor
cbi(ENC3_PHASEA_DDR, ENC3_PHASEA_PIN);
sbi(ENC3_PHASEA_PORT, ENC3_PHASEA_PIN);
// set encoder direction pin for input and apply pullup resistor
cbi(ENC3_PHASEB_DDR, ENC3_PHASEB_PIN);
sbi(ENC3_PHASEB_PORT, ENC3_PHASEB_PIN);
// configure interrupts for any-edge triggering
sbi(ENC3_ICR, ENC3_ISCX0);
cbi(ENC3_ICR, ENC3_ISCX1);
// enable interrupts
sbi(IMSK, ENC3_INT); // ISMK is auto-defined in encoder.h
#endif
// enable global interrupts
sei();
}
// encoderOff() disables hardware and stops encoder position updates
void encoderOff(void)
{
// disable encoder interrupts
#ifdef ENC0_SIGNAL
// disable interrupts
sbi(IMSK, INT0); // ISMK is auto-defined in encoder.h
#endif
#ifdef ENC1_SIGNAL
// disable interrupts
sbi(IMSK, INT1); // ISMK is auto-defined in encoder.h
#endif
#ifdef ENC2_SIGNAL
// disable interrupts
sbi(IMSK, INT2); // ISMK is auto-defined in encoder.h
#endif
#ifdef ENC3_SIGNAL
// disable interrupts
sbi(IMSK, INT3); // ISMK is auto-defined in encoder.h
#endif
}
// encoderGetPosition() reads the current position of the encoder
s32 encoderGetPosition(u08 encoderNum)
{
// sanity check
if(encoderNum < NUM_ENCODERS)
return EncoderState[encoderNum].position;
else
return 0;
}
// encoderSetPosition() sets the current position of the encoder
void encoderSetPosition(u08 encoderNum, s32 position)
{
// sanity check
if(encoderNum < NUM_ENCODERS)
EncoderState[encoderNum].position = position;
// else do nothing
}
#ifdef ENC0_SIGNAL
//! Encoder 0 interrupt handler
SIGNAL(ENC0_SIGNAL)
{
// encoder has generated a pulse
// check the relative phase of the input channels
// and update position accordingly
if( ((inb(ENC0_PHASEA_PORTIN) & (1<<ENC0_PHASEA_PIN)) == 0) ^
((inb(ENC0_PHASEB_PORTIN) & (1<<ENC0_PHASEB_PIN)) == 0) )
{
EncoderState[0].position++;
}
else
{
EncoderState[0].position--;
}
}
#endif
#ifdef ENC1_SIGNAL
//! Encoder 1 interrupt handler
SIGNAL(ENC1_SIGNAL)
{
// encoder has generated a pulse
// check the relative phase of the input channels
// and update position accordingly
if( ((inb(ENC1_PHASEA_PORTIN) & (1<<ENC1_PHASEA_PIN)) == 0) ^
((inb(ENC1_PHASEB_PORTIN) & (1<<ENC1_PHASEB_PIN)) == 0) )
{
EncoderState[1].position++;
}
else
{
EncoderState[1].position--;
}
}
#endif
#ifdef ENC2_SIGNAL
//! Encoder 2 interrupt handler
SIGNAL(ENC2_SIGNAL)
{
// encoder has generated a pulse
// check the relative phase of the input channels
// and update position accordingly
if( ((inb(ENC2_PHASEA_PORTIN) & (1<<ENC2_PHASEA_PIN)) == 0) ^
((inb(ENC2_PHASEB_PORTIN) & (1<<ENC2_PHASEB_PIN)) == 0) )
{
EncoderState[2].position++;
}
else
{
EncoderState[2].position--;
}
}
#endif
#ifdef ENC3_SIGNAL
//! Encoder 3 interrupt handler
SIGNAL(ENC3_SIGNAL)
{
// encoder has generated a pulse
// check the relative phase of the input channels
// and update position accordingly
if( ((inb(ENC3_PHASEA_PORTIN) & (1<<ENC3_PHASEA_PIN)) == 0) ^
((inb(ENC3_PHASEB_PORTIN) & (1<<ENC3_PHASEB_PIN)) == 0) )
{
EncoderState[3].position++;
}
else
{
EncoderState[3].position--;
}
}
#endif
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