#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

#define OUTPUT_PIN 5
#define POT_PIN A1

const int MIN_FREQUENCY = 100;
const int MAX_FREQUENCY = 600;
const int MAX_READ_VALUE = 1023;

int potValue, frequency, prevSetFreq = 0;

void setup(){
  // Setup serial
  Serial.begin(115200);

  // Set output pin
  pinMode(OUTPUT_PIN, OUTPUT);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) { 
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }
  display.clearDisplay();
}

void loop(){
  // Convert potValue to freqency
  potValue = analogRead(POT_PIN); // 1023 max
  frequency = ((potValue / (float) MAX_READ_VALUE) * (MAX_FREQUENCY - MIN_FREQUENCY)) + MIN_FREQUENCY;

  // Set frequency (if changed)
  if (frequency != prevSetFreq) {
    refreshDisplay();
    prevSetFreq = frequency;
  }
  
  // Set output
  tone(OUTPUT_PIN, frequency);
}

void refreshDisplay() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0, 10);
  display.print("Frequency: ");
  display.println(frequency);
  display.setCursor(0, 20);
  display.display(); 
}