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

#define PIN_SOIL_SENSOR 32
#define SCREEN_WIDTH 128 // OLED width,  in pixels
#define SCREEN_HEIGHT 64 // OLED height, in pixels

// create an OLED display object connected to I2C
Adafruit_SSD1306 oled(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

unsigned int soil_val=0;
unsigned int water_soil_val=1680;
unsigned int air_soil_val=3620;
unsigned int soil_percent=0;
void setup()
{
  Serial.begin(115200);
  // initialize OLED display with I2C address 0x3C
  if (!oled.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("failed to start SSD1306 OLED"));
    while (1);
  }
  delay(500);         // wait 500 miliseconds for initializing
  oled.clearDisplay(); // clear display
}
void loop()
{
  oled.setTextSize(1);         // set text size
  oled.setTextColor(WHITE);    // set text color
  oled.setCursor(10, 2);       // set position to display (x,y)
  oled.println("Soil humedity (%)"); // set text
   oled.setTextSize(2);         // set text size
  oled.setCursor(40, 20);       // set position to display (x,y)
  oled.print(soilPercent()); // set text
  oled.println(" %"); // set text
  oled.display();              // display on OLED
  delay(10);
  oled.clearDisplay(); // clear display
}
int soilPercent()
{
  soil_val = analogRead(PIN_SOIL_SENSOR);
  soil_percent = map(soil_val,air_soil_val,water_soil_val, 0, 100);
  Serial.print("Soil humedity percent: ");
  Serial.println(soil_percent);
  return soil_percent;
  delay(100); 
}