#include <Adafruit_GFX.h> 
#include <Adafruit_SSD1306.h>
#include <Fonts/FreeSansBold9pt7b.h> 
#include <Fonts/Picopixel.h> 

#define ENCODER_CLK 2 
#define ENCODER_DT  3 
#define ENCODER_SW  4 

uint8_t volume = 50; 
uint8_t bass = 25; 
uint8_t treble = 66; 

typedef enum {
  SET_VOLUME, 
  SET_BASS, 
  SET_TREBLE,
}  Mode;

Mode mode = SET_VOLUME;

Adafruit_SSD1306 display(128, 64, &Wire, -1);

void nextMode() {
  switch (mode) {
    case SET_VOLUME: 
      mode = SET_BASS; 
      break; 
  }
}

void setup(){

}

void loop(){
  
}