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

#define TRIGGER_PIN 2
#define ECHO_PIN 3

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

void setup() {
  // put your setup code here, to run once:
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);
  display.display();
  display.clearDisplay();
  pinMode(TRIGGER_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  display.clearDisplay();
  long duration, distance;
  digitalWrite(TRIGGER_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGGER_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGGER_PIN, LOW);
  duration = pulseIn(ECHO_PIN, HIGH);
  distance = (duration * 0.0343) / 2;
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0,0);
  display.print("Masofa: ");
  display.print(distance);
  display.print(" sm");
  int radius = map(distance, 0, 400, 0, 30);
  display.drawCircle(64, 38, radius, SSD1306_WHITE);
  display.fillCircle(64, 38, radius, SSD1306_WHITE);
  display.display();
  delay(500);
}