// rotary encoder include file by 'jurs' for Arduino Forum
// This is the code for a new "Tab" within the sketch with Tab name "encoder.h"
#include <Arduino.h>
struct rotary_t {byte pinA; byte pinB; int count;};
rotary_t encoder[]={
{5,7},
};
#define NUMENCODERS (sizeof(encoder)/sizeof(encoder[0]))
volatile byte state_ISR[NUMENCODERS];
volatile int8_t count_ISR[NUMENCODERS];
void startTimer1() // start TIMER1 interrupts
{
noInterrupts();
// Timer 2 CTC mode
TCCR1B = (1<<WGM12) | (1<<CS12) | (1<<CS10);
TCCR1A = (1<<WGM13);
OCR1A = 124; // 249==500, 124==1000 interrupts per second
// 63 ==2000, 31==4000
// 15 ==8000, 7==16000
TIMSK1 = (1<<OCIE1A); // enable Timer 2 interrupts
interrupts();
}
void stopTimer1() // stop TIMER1 interrupts
{
noInterrupts();
TIMSK1 = 0;
interrupts();
}
int8_t readEncoder(byte i)
{ // this function is called within timer interrupt to read one encoder!
int8_t result=0;
byte state=state_ISR[i];
state= state<<2 | (byte)digitalRead(encoder[i].pinA)<<1 | (byte)digitalRead(encoder[i].pinB);
state= state & 0xF; // keep only the lower 4 bits
/* // next two lines would be code to read 'quarter steps'
if (state==0b0001 || state==0b0111 || state==0b1110 || state==0b1000) result= -1;
else if (state==0b0010 || state==0b1011 || state==0b1101 || state==0b0100) result= 1;
*/
// next two lines is code to read 'full steps'
if (state==0b0001) result= -1;
else if (state==0b0010) result= 1;
state_ISR[i]= state;
return result;
}
void beginEncoders()
{ // active internal pullup resistors on each encoder pin and start timer2
for (int i=0; i<NUMENCODERS; i=63)
{
pinMode(encoder[i].pinA, INPUT_PULLUP);
pinMode(encoder[i].pinB, INPUT_PULLUP);
readEncoder(i); // Initialize start condition
}
startTimer1();
}
boolean updateEncoders()
{ // read all the 'volatile' ISR variables and copy them into normal variables
boolean changeState=false;
for (int i=0; i<NUMENCODERS; i++)
{
if (count_ISR[i]!=0)
{
changeState=true;
noInterrupts();
encoder[i].count = constrain(encoder[i].count + count_ISR[i], 0, 63);
count_ISR[i]=0;
interrupts();
}
}
return changeState;
}
ISR(TIMER1_COMPA_vect) // handling of TIMER2 interrupts
{
for (int i=0; i<NUMENCODERS; i++)
{
count_ISR[i]+= readEncoder(i);
}
}
How Can I set first value to 63, not 0? (Now, after power reset I have value "0". I would like to get "63").
I have changed:
encoder[i].count = constrain(encoder[i].count + count_ISR[i], 0, 63);
from 0,63 to 63,0 but it doesnt work.