Encoder + Bounce2 Library

Question

I am working towards debouncing my keyes rotary encoder using the Bounce2 library found here ( https://github.com/thomasfredericks/Bounce2 ).

I believe the problem lies in my code as there isn't much in terms of a circuit. The encoder is connected to my arduino as follows

• 5V : connected to 5v out on arduino
• GND : connected to GND
• SW : connected to pin A1
• DT : connected to pin 3
• CLK : connected to pin 2

I am trying to call an ISR from a CLK input. When the ISR is called it should increment or decrement a value based on the direction the encoder was turned. This encoder is tied to an ISR because it will be used for user input and I would like it to remain responsive throughout the sketch.

Previously, I was using millis() to debounce the encoder, but I was still having trouble receiving more than one input from the encoder. I was hoping that this libary would resolve this issue.

The current output of the code I have included never increments/decrements the starting value no matter which direction the encoder is turned. In short, it always outputs 0.

If someone could explain what I am doing wrong that would be wonderful! Then maybe, but just maybe, I can stop beating my head against my desk. :p

Thanks, Kevin

#include <Bounce2.h>
#define sw A1
#define LED_PIN 9
#define clk 2
#define dt 3
int ledState = LOW;
int onOff = LOW;
volatile int virtualPosition = 0;
int lastCount = 0;
// Initiate bounce objects
Bounce debouncerSW = Bounce();
Bounce debouncerROT = Bounce();
void setup() {
 Serial.begin(115200);
 pinMode(sw, INPUT_PULLUP);
 pinMode(clk, INPUT);
 pinMode(dt, INPUT);
 pinMode(LED_PIN, OUTPUT);
 // set up button instace
 debouncerSW.attach(sw);
 debouncerSW.interval(100);
 // set up rotary encoder instance
 debouncerROT.attach(clk);
 debouncerROT.interval(10);
 // setup the LED
 digitalWrite(LED_PIN, ledState);
 // attach ISR
 attachInterrupt(digitalPinToInterrupt(clk), isr, LOW);
 Serial.println("Start"); // just to let me know sketch has finished setup
}
void loop() {
 debouncerSW.update();
 if ( debouncerSW.fell() ) {
 ledState = !ledState;
 onOff = !onOff;
 digitalWrite(LED_PIN, ledState);
 //read-outs
 Serial.print("onOff = ");
 Serial.println(onOff);
 }
 virtualPosition = lastCount;
 //read-outs
 Serial.print ("lastCount = ");
 Serial.println (lastCount);
 delay(1000); // for readability / simulates delay time for rest of main sketch
} // end main loop
void isr () {
 // Update the Bounce instance :
 debouncerROT.update();
 if (debouncerROT.fell()) {
 if (digitalRead(dt) == LOW)
 {
 virtualPosition -- ; // Could be -5 or -10
 }
 else {
 virtualPosition ++ ; // Could be +5 or +10
 }
 // Restrict value from 0 to 100
 virtualPosition = min(100, max(0, virtualPosition));
 }
} // end ISR

• kevinconnectable: I also want to note that no form of hardware debouncing is in use. The rotary encoder is connected directly to the arduino with no passive components in place.
• James Waldby - jwpat7: See my answer to How to read RPS for fast rotation with status change method in Arduino?. Also see my comment to other answer there, "Implemented with a state machine, quadrature coding does not need debouncing. Bounce can cause invalid states or extra states, but they cancel out." In other words, debouncing rotary encoder inputs is a wrongheaded approach.
• kevinconnectable: @jwpat7 Thank you! I will take a look!
• Delta_G: I’ve always found with encoders that hardware denouncing saves me a lot of trouble. All you need is a couple of small caps.