Encoder.cpp

#include <stdlib.h>
#include "Energia.h"
#include "Encoder.h"
 
/* Variables used in the ISR should be volatile */
volatile uint32_t enc_left_cnt = 0;
volatile uint32_t enc_right_cnt = 0;
volatile uint8_t enc_left_wheel_dir = 0;
volatile uint8_t enc_right_wheel_dir = 0;
 
/* Pins used by the encoder */
uint8_t _era_pin;
uint8_t _erb_pin;
uint8_t _ela_pin;
uint8_t _elb_pin;
 
void triggerLeftEncoder()
{
    enc_left_cnt++;
 
    /* The wheel direction can be determined by the second encoder pin */
    enc_left_wheel_dir = digitalRead(_ela_pin);
}
 
void triggerRightEncoder()
{
    enc_right_cnt++;
 
    /* The wheel direction can be determined by the second encoder pin */
    enc_right_wheel_dir = digitalRead(_era_pin);
}
 
void setupEncoder(uint8_t ela_pin, uint8_t elb_pin, uint8_t era_pin, uint8_t erb_pin)
{
    _era_pin = era_pin;
    _erb_pin = erb_pin;
    _ela_pin = ela_pin;
    _elb_pin = elb_pin;
 
    /* Encoder drives pins high during pulse so by default they should be pulled low */
    pinMode(_ela_pin, INPUT_PULLDOWN);
    pinMode(_elb_pin, INPUT_PULLDOWN);
    pinMode(_era_pin, INPUT_PULLDOWN);
    pinMode(_erb_pin, INPUT_PULLDOWN);
 
    /* Only count the rising edge of the encoder */
    attachInterrupt(digitalPinToInterrupt(erb_pin), triggerRightEncoder, RISING);
    attachInterrupt(digitalPinToInterrupt(elb_pin), triggerLeftEncoder, RISING);
}
 
uint32_t getEncoderRightCnt()
{
    return enc_right_cnt;
}
 
uint32_t getEncoderLeftCnt()
{
    return enc_left_cnt;
}
 
void resetLeftEncoderCnt()
{
    enc_left_cnt = 0;
}
 
void resetRightEncoderCnt()
{
    enc_right_cnt = 0;
}
 
uint8_t getLeftWheelDir()
{
    return enc_left_wheel_dir;
}
uint8_t getRightWheelDir()
{
    return enc_right_wheel_dir;
}