/*Description:


 * Circuit:
 *   Arduino        Component        
 *      2  ------->  start button       
 *      3  ------->  select button
 *      4  ------->  up button 
 *      5  ------->  down button
 *      A4 ------->   sda oled screen
 *      A5 ------->   scl oled screen
 
 */

//Libraries
#include <Wire.h>
#include <SPI.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

// Define pins
#define startBtnPIN 2   // D2
#define selectBtnPIN 3  // D3
#define upBtnPIN 4     // D4
#define downBtnPIN 5  // D5

#define OLED_RESET     -1 // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3C ///< See datasheet for Address; 0x3D for 128x64, 0x3C for 128x32

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

bool stateStartBtn=0;
bool stateSelectBtn=0;
bool stateUpBtn=0;
bool stateDownBtn=0;
bool mode=0;
bool parameter=0;
int parameter1=0;
int parameter2=0;
int AperatureValues = 16;
int IsoValues = 11;


void setup() {
   // initialize serial port
  Serial.begin(9600);
  Wire.begin();
  
  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }
  

  display.clearDisplay();
  display.setTextSize(1); // Draw 1X-scale text
  display.setTextColor(SSD1306_WHITE);
  
  // setup button
  pinMode(startBtnPIN, INPUT_PULLUP);
  pinMode(selectBtnPIN, INPUT_PULLUP);
  pinMode(upBtnPIN, INPUT_PULLUP);
  pinMode(downBtnPIN, INPUT_PULLUP);

  display.setCursor(0, 0);
  display.println("...READY");
  display.println("      ");
  display.println("press Start button");
  display.println("      ");
  display.println("select to configure");
  display.display();
  delay(1000);

}

void loop() {
 
  readButtons();

}

void readButtons(){
//=====start button==========
  if (digitalRead(startBtnPIN)==LOW && stateStartBtn == 0){
      stateStartBtn=1;
      Serial.println("start button is pressed");

      if(mode==0){
        display.clearDisplay();
        display.setCursor(0, 0);
        display.println("The process ");
        display.println("      ");
        display.println("has started!");
        display.display();
      }

   }
   else if (digitalRead(startBtnPIN)==HIGH && stateStartBtn == 1){
      stateStartBtn=0;
   }
//===select button=================
   if (digitalRead(selectBtnPIN)==LOW && stateSelectBtn == 0){
      stateSelectBtn=1;
     if(mode==0){
        mode=1;
        display.clearDisplay();
        display.setCursor(10, 10);
        display.print("Parameter 1= ");
        display.println(parameter1);
        display.display();      
        
     }
     else if(mode==1 && parameter==0){
        parameter=1;
        display.clearDisplay();
        display.setCursor(10, 10);
        display.print("Parameter 2= ");
        display.println(parameter2);
        display.display();
        
      }
     else if(parameter==1) {
        mode=0; 
        parameter=0;
        screenReady();
      }

      Serial.println("select button is pressed");

    //  Serial.print("Mode="); Serial.println(mode);
    //  Serial.print("Parameter="); Serial.println(parameter);

   }
   else if (digitalRead(selectBtnPIN)==HIGH && stateSelectBtn == 1){
      stateSelectBtn=0;
   }
//=====up button==========
  if (digitalRead(upBtnPIN)==LOW && stateUpBtn == 0 && mode==1){
      stateUpBtn=1;
      Serial.println("up button is pressed");

      display.clearDisplay();
      display.setCursor(10, 10);
          
      if(parameter==0){
        if(parameter1<15)  parameter1++;
        
        display.clearDisplay();
        display.setCursor(10, 10);
        display.print("Parameter 1= ");
        display.println(parameter1);
        display.display();   
      }
      else if(parameter==1){
        if(parameter2<10) parameter2++;
        
        display.clearDisplay();
        display.setCursor(10, 10);
        display.print("Parameter 2= ");
        display.println(parameter2);
        display.display();   
      }
      
      

   }
   else if (digitalRead(upBtnPIN)==HIGH && stateUpBtn == 1){
      stateUpBtn=0;
   }
//=====down button==========
  if (digitalRead(downBtnPIN)==LOW && stateDownBtn == 0 && mode==1){
      stateDownBtn=1;
      Serial.println("down button is pressed");

      display.clearDisplay();
      display.setCursor(10, 10);

      if(parameter==0){
        if(parameter1>0)  parameter1--;
        
        display.clearDisplay();
        display.setCursor(10, 10);
        display.print("Parameter 1= ");
        display.println(parameter1);
        display.display();   
      }
      else if(parameter==1){
        if(parameter2>0) parameter2--;
        
        display.clearDisplay();
        display.setCursor(10, 10);
        display.print("Parameter 2= ");
        display.println(parameter2);
        display.display();   
      }

   }
    else if (digitalRead(downBtnPIN)==HIGH && stateDownBtn == 1){
      stateDownBtn=0;
   }
}


void screenReady(){
  // Display start
  display.clearDisplay();
  display.setCursor(0, 0);
  display.println("...READY");
  display.println("      ");
  display.println("press Start button");
  display.println("      ");
  display.println("select to configure");
  display.display();
  delay(1000);
}