TEA5767 FM radio with rotary encoder - Arduino for beginners

#include <Wire.h>
#include <TEA5767Radio.h>

#define CLK 2
#define DT 3
#define SW 4
TEA5767Radio radio = TEA5767Radio();

float counter = 107.7;
int currentStateCLK;
int lastStateCLK;

String currentDir ="";
unsigned long lastButtonPress = 0;


void setup()
     {
         pinMode(CLK,INPUT);
           pinMode(DT,INPUT);
           pinMode(SW, INPUT_PULLUP);
         lastStateCLK = digitalRead(CLK);
         Serial.begin(9600);
           Serial.print(" Frecvency: ");
           Serial.println(counter);
         Wire.begin();
         radio.setFrequency(107.7);
     }

void loop()
     {
        currentStateCLK = digitalRead(CLK);
          if (currentStateCLK != lastStateCLK  && currentStateCLK == 1)
           {
              if (digitalRead(DT) != currentStateCLK)
                 {
                          counter = counter + 0.1;
                    if (counter > 108.1)
                       {
                         counter = 87.5;
                       }
                          currentDir ="UP";
                    radio.setFrequency(counter);
                     } else
                      {
                                counter = counter - 0.1;
                          if (counter < 87.5)
                             {
                                counter = 108;
                             }
                          currentDir ="DOWN";
                    radio.setFrequency(counter);
                          }
                  Serial.print("Direction: ");
                  Serial.print(currentDir);
                  Serial.print(" - Frecvency: ");
                  Serial.println(counter);
            }

  lastStateCLK = currentStateCLK;
  int btnState = digitalRead(SW);
    if (btnState == LOW)
        {
               if (millis() - lastButtonPress > 50)
              {
                       Serial.println("Button pressed!");
                  }
               lastButtonPress = millis();
          }
    delay(1);
     }