//libs
#include <Wire.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_GFX.h>
#include <stdio.h>

//Ultrasonic
const int Trig  = 3;
const int Echo  = 2;
  //Data
  long  duration;
  float cm;

//Potentiometer
int   PotSens   = A0;
int   PotDatta  = 0;
int   ButtonPin = 5;
int   Button    = 0;
float Pot2cm    = 0;

//Error
int   ErrorDebug1 = 8;
int   ErrorDebug2 = 9;
char  ErrorChar;

//Oled Screen
#define SCREEN_WIDTH    128
#define SCREEN_HEIGHT   64
#define OLED_RESET      4
#define SCREEN_ADDRESS  0x3C
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

void setup() {
  
  Serial.begin(9600);

  //Pinmode
  pinMode(Trig,     OUTPUT);
  pinMode(Echo,     INPUT);
  pinMode(ButtonPin,INPUT);

  pinMode(PotSens,  INPUT);
  
  //Screen
   if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    for(;;); 
    }
  display.display();
  display.clearDisplay();
}

void loop() {

    HCsens();

    PotDatta = analogRead(PotSens);
    Pot2cm = 0.0293255132*(PotDatta);

    Error();

    Button = digitalRead(ButtonPin);

    Display();
    display.display();
    delay(20);

    //Serial.println("--------------------------");
    //delay(200);

}

int Error(){

    if ((Pot2cm >= (cm + 0.4)) || (Pot2cm  <= (cm - 0.4))){
      digitalWrite(ErrorDebug1, HIGH);
      digitalWrite(ErrorDebug2, LOW);
        /*Serial.println(digitalRead(ErrorDebug1));
        Serial.println(digitalRead(ErrorDebug2));
        Serial.println("Error");
        delay(200);
        */  
      ErrorChar = 'S';

    }
    else{
      digitalWrite(ErrorDebug2, HIGH);
      digitalWrite(ErrorDebug1, LOW);
        /*Serial.println(digitalRead(ErrorDebug1));
        Serial.println(digitalRead(ErrorDebug2));
        Serial.println("No Error");
        delay(200);
        */
      ErrorChar = 'N';

    }
}

int HCsens(){

  digitalWrite(Trig, LOW);
  delayMicroseconds(2);
  digitalWrite(Trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(Trig, LOW);

  duration = pulseIn(Echo, HIGH);
  cm = us2Cm(duration) - 5;
    
}

float us2Cm (float microseconds) {
  return microseconds / 29 / 2;
}

void Display(void){

  display.clearDisplay();
  display.setTextSize(1);             
  display.setTextColor(SSD1306_WHITE);        
  display.setCursor(13,0);

  display.println(F("Movimiento lineal"));
  display.drawRect(0, 10, 128, 1, WHITE);

  display.setCursor(1,15);
  display.print("Boton:");
  display.print(Button);

  display.setCursor(70,15);
  display.print("Error?:");
  display.print(ErrorChar);

  display.setTextSize(2);
  display.setCursor(1,25);
  display.print("Sens:");
  display.print(cm);

  display.setCursor(1,45);
  display.print("Cnta:");
  display.print(Pot2cm);
  
}