Try this:
/* interrupt routine for Rotary Encoders
The average rotary encoder has three pins, seen from front: A C B
Clockwise rotation A(on)->B(on)->A(off)->B(off)
CounterCW rotation B(on)->A(on)->B(off)->A(off)
and may be a push switch with another two pins, pulled low at pin 8 in this case
*/
// usually the rotary encoders three pins have the ground pin in the middle
enum PinAssignments {
encoderPinA = 2, // right (labeled DT on our decoder, yellow wire)
encoderPinB = 3, // left (labeled CLK on our decoder, green wire)
clearButton = 8 // switch (labeled SW on our decoder, orange wire)
// connect the +5v and gnd appropriately
};
volatile byte encoderPos = 0; // a counter for the dial
byte lastReportedPos = 1; // change management
static boolean rotating = false; // debounce management
// interrupt service routine vars
boolean A_set = false;
boolean B_set = false;
int pressCount = 0;
void setup() {
pinMode(encoderPinA, INPUT_PULLUP); // new method of enabling pullups
pinMode(encoderPinB, INPUT_PULLUP);
pinMode(clearButton, INPUT_PULLUP);
pinMode(9, OUTPUT);
pinMode(13, OUTPUT);
// turn on pullup resistors (old method)
//digitalWrite(encoderPinA, HIGH);
// digitalWrite(encoderPinB, HIGH);
// digitalWrite(clearButton, HIGH);
// encoder pin on interrupt 0 (pin 2)
attachInterrupt(0, doEncoderA, CHANGE);
// encoder pin on interrupt 1 (pin 3)
attachInterrupt(1, doEncoderB, CHANGE);
Serial.begin(9600); // output
}
// main loop, work is done by interrupt service routines, this one only prints stuff
void loop() {
rotating = true; // reset the debouncer
if (lastReportedPos != encoderPos) {
Serial.print("Index:");
Serial.println(encoderPos, DEC);
lastReportedPos = encoderPos;
}
if (digitalRead(clearButton) == LOW ) {
/*delay(300);
pressCount ++;
//Reset count if over max mode number
if(pressCount > 2)
{
pressCount = 0;
}
switch (pressCount) {
case 0:
digitalWrite(13, LOW);
break;
case 1:
analogWrite(9,25);
break;
case 2:
analogWrite(9,0);
digitalWrite(13, HIGH);
break;
}*/
encoderPos = 0;
}
switch (encoderPos) {
case 0:
digitalWrite(9, LOW);
digitalWrite(13, LOW);
break;
case 1:
digitalWrite(9, LOW);
digitalWrite(13, HIGH);
break;
case 2:
digitalWrite(13, LOW);
digitalWrite(9, HIGH);
break;
case 3:
digitalWrite(13, LOW);
digitalWrite(9, HIGH);
break;
}
}
// Interrupt on A changing state
void doEncoderA() {
// debounce
if ( rotating ) delay (1); // wait a little until the bouncing is done
// Test transition, did things really change?
if ( digitalRead(encoderPinA) != A_set ) { // debounce once more
A_set = !A_set;
// adjust counter + if A leads B
if ( A_set && !B_set && encoderPos != 5)
{
encoderPos += 1;
}
if ( A_set && !B_set && encoderPos == 5)
{
encoderPos = 0;
}
rotating = false; // no more debouncing until loop() hits again
}
}
// Interrupt on B changing state, same as A above
void doEncoderB() {
if ( rotating ) delay (1);
if ( digitalRead(encoderPinB) != B_set) {
B_set = !B_set;
// adjust counter - 1 if B leads A
if ( B_set && !A_set && encoderPos == 0)
{
encoderPos = 5;
}
if ( B_set && !A_set )
{
encoderPos -= 1;
}
rotating = false;
}
}
Works well for limiting encoder, sketch is set for a limit of 4.
Check on serial monitor.