DisplayESP32/DisplayESP32.ino

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#define __DEBUG__

//The following constants are used to configure the behaviour of the interface
// MAX_OPTIONS defines the maximum number of options a menu can hold
// MAX_MENUS declares the maximum number of menu screens in the interface
// MAX_GRAPHS is the maximum number of graphs to create
// DISP_WIDTH and DISP_HEIGHT are hardware specific (SSD1306)
// REFRESH: is the time in miliseconds the interface will take in refreshing (this time affects the loop, keep that in mind)

#define MAX_OPTIONS 10      //Maximum number of options for each menu
#define MAX_MENUS 3
#define MAX_GRAPHS 3
#define MAX_MODIFIERS 3
#define DISP_WIDTH 128      // OLED display width
#define DISP_HEIGHT 64      // OLED display height
#define REFRESH 10          //Refresh time in ms
#define ADDRESS 0x3C            //I2C address of the display

Adafruit_SSD1306 display(DISP_WIDTH, DISP_HEIGHT, &Wire, -1);

class Option{
  private:

  int sizex;    //Defines the size it will occupy in the x axis (width), this value is gotten from the menu
  int sizey;    //Defines the height of the option (this value is gotten from the menu it belongs to)
  String content;   //Text of the option
  int pos;      //Defines the position it has in the menu
  int textSpacing;   //According to the height, defines the space for the text, so that it's vertically centered
  bool fill = false;  //In case an option is not selected this should be false
  bool disp = false;   //In case an option is not configured, it should be false and, thus hidden
  int destinationType;   //Defines what the option leads to (another menu, graph, something else)
  int destinationIndex;  //Defines where the option leads to (index of the destination)

  public:

  //Option(){}
  
  //Method to configure an option, all attributes are assigned, and disp is true, so the option can be displayed
  void configure(String content, int sizex, int sizey, int pos, int destinationType, int destinationIndex){
    this->sizex = sizex;
    this->sizey = sizey;
    this->content = content;
    this->pos = pos;
    this->destinationType = destinationType;
    this->destinationIndex = destinationIndex;
    this->disp = true;
    this->textSpacing = ((sizey - 7)/2) + 7;
  }

  int getDestinationType(){
    int destinationType = this->destinationType;
    return destinationType;
  }

  int getDestinationIndex(){
    int destinationIndex = this->destinationIndex;
    return destinationIndex;
  }

//This method draws each option

  void drawopt(int page, int pos, int optPPage){
    if(this->disp){    //Checks if the option was configured and, as a result, is displayable
      if(this->pos == pos){   //If the position of the option corresponds to the position passed to the function, then it should be selected
        display.fillRect(0, (this->sizey)*(this->pos) + 1 - (page*optPPage*this->sizey), this->sizex, this->sizey, WHITE);
        display.setTextColor(SSD1306_BLACK);
        display.setCursor(5, (this->sizey)*(this->pos + 1) - (page*optPPage*this->sizey) - this->textSpacing);
        display.print(this->content);
        display.setTextColor(SSD1306_WHITE);
      }
      else{                  //If the option is not selected, the rectangle containing it shouldn't be filled
        display.drawRect(0, (this->sizey)*(this->pos) + 1 - (page*optPPage*this->sizey), this->sizex, this->sizey, WHITE);
        display.setCursor(5, (this->sizey)*(this->pos + 1) - (page*optPPage*this->sizey) - this->textSpacing);
        display.print(this->content);
      }
    }
  }
};

class Menu{    //ContentType (0)
  private:

  int sizex;                  //X size for each option in the menu
  int sizey;                  //Y size of each option in the menu
  int options = 0;            //This indicates the number of options created
  int pos = 0;                //This indicates the position of the cursor
  int page = 0;               //If the menu is too long, this indicates the page that is being displayed
  Option opt[MAX_OPTIONS];
  int optPPage;

  int previousScreen = 0;
  int previousContentType = 0;
  
  public:

  void configure(int sizex, int sizey){   //This method configures the menu created from Screen
    this->sizex = sizex;
    this->sizey = sizey;
    this->optPPage = DISP_HEIGHT / this->sizey;
  }

  //The following method is used to created an option for the menu
  void createOption(String content, bool destinationTypeMenu, int destinationIndex){
    //The option takes the place in the array defined by the options number variable (options), which is later increased.
    this->opt[this->options].configure(content, this->sizex, this->sizey, this->options++, destinationTypeMenu, destinationIndex);
  }

  int extractDestinationType(){
    int destinationType = this->opt[this->pos].getDestinationType();
    return destinationType;
  }

  int extractDestinationIndex(){
    int destinationIndex = this->opt[this->pos].getDestinationIndex();
    return destinationIndex;
  }

//The following method draws the whole menu by drawing every option configured within it
  void drawMenu(){
    display.clearDisplay();
    this->page = pos/this->optPPage;  //The current page is obtained by dividing the position by the number of options per page (only integer)
    for(int i = 0; i < options; i++){
      this->opt[i].drawopt(this->page, this->pos, this->optPPage);
    }
    display.display();
  }
  //Methods used by Screen
  int extractPos(){ //Gets the current position of the cursor
    return(this->pos);
  }

  int extractOptNumber(){  //Gets the number of options in the menu
    return(this->options);
  }

  void increasePos(){  //Increases the position of the cursor
    this->pos++;
  }

  void decreasePos(){   //Decreases the position of the cursor
    this->pos--;
  }

//Both of the following methods store the values of the previous screen passed as parameters by Screen

  void setPreviousScreen(int prev){
    this->previousScreen = prev;
  }

  void setPreviousContentType(int prev){
    this->previousContentType = prev;
  }

//Both of the following methods retrieve the values of the screen previous to the menu containing these data.
  int getPreviousScreen(){
    int prev = this->previousScreen;
    return prev;
  }

  int getPreviousContentType(){
    int prev = this->previousContentType;
    return prev;
  }
};

class Graph{     //ContentType (1)
  private:

  String title;
  char graphType;       //'a' Vertical Bar, 'b' Horizontal Bar, 'c' Cartesian Graph

  //Assign whatever value in "configure(..." if a parameter is not required for the specified graphType
  
  double value;         //For: Vertical Bar  Horizontal Bar  Cartesian
  double xpos;          //For: Vertical Bar  Horizontal Bar  Cartesian
  double ypos;          //For: Vertical Bar  Horizontal Bar  Cartesian
  double height;        //For: Vertical Bar  Horizontal Bar  Cartesian
  double width;         //For: Vertical Bar  Horizontal Bar  Cartesian
  double yminimum;      //For: Vertical Bar                  Cartesian
  double ymaximum;      //For: Vertical Bar                  Cartesian
  double xminimum;      //For:               Horizontal Bar  Cartesian
  double xmaximum;      //For:               Horizontal Bar  Cartesian
  double yStepSize;     //For: Vertical Bar                  Cartesian
  double xStepSize;     //For:               Horizontal Bar  Cartesian
  int digit;         //For: Vertical Bar  Horizontal Bar  Cartesian
  double x;
  double yrange;
  double xrange;
  double ox;
  double oy;
  double count;
  double graphScale;
  bool redraw = true;
  
  int previousScreen = 0;
  int previousContentType = 0;
  
  public:

//This method configures the graph created, defines its parameters according the type of graph selected.
  void configure(String title, char graphType, double xpos, double ypos, double width, double height,
  double yminimum, double ymaximum, double xminimum, double xmaximum, double yStepSize, double xStepSize, int digit){
    this->title = title;
    this->graphType = graphType;
    this->yminimum = yminimum;
    this->ymaximum = ymaximum;
    this->xminimum = xminimum;
    this->count = xminimum;
    this->xmaximum = xmaximum;
    this->height = height;
    this->width = width;
    this->yStepSize = yStepSize;
    this->xStepSize = xStepSize;
    this->digit = digit;
    this->xpos = xpos;
    this->ypos = ypos;
    switch(graphType){
      case 'a':
      this->yrange = ymaximum - yminimum;
      this->graphScale = (yStepSize) * (height / this->yrange) - .001; //Adjusts the scale of the graph, according to the range and the size of the step
      break;

      case 'b':
      this->xrange = xmaximum - xminimum;
      this->graphScale = (xStepSize) * (width / this->xrange) - .001; //Adjusts the scale of the graph, according to the range and the size of the step
      break;

      case 'c':
      this->yrange = ymaximum - yminimum;
      this->xrange = xmaximum - xminimum;
      break;
    }
  }

  void drawGraph(){
    double level, data, i;
    switch(graphType){
      case 'a':
      double my;
  
      if (this->redraw) {  //Prints the labels
        display.clearDisplay();
        this->redraw = false;
        display.fillRect(0, 0,  127 , 14, SSD1306_WHITE);
        display.setTextColor(SSD1306_BLACK, SSD1306_WHITE);
        display.setTextSize(1);
        display.setCursor(2, 4);
        display.println(this->title);
  
        for (i = 0; i <= this->height; i += this->graphScale) {
          my =  this->ypos - this->height + i;
          display.drawFastHLine(this->xpos + this->width + 1, my,  5, SSD1306_WHITE);
          // draw lables
          display.setTextSize(1);
          display.setTextColor(SSD1306_WHITE, SSD1306_BLACK);
          display.setCursor(this->xpos + this->width + 12, my - 3 );
          data = this->ymaximum - ( i * (this->yStepSize / this->graphScale));
          display.print(data, this->digit);
        }
      }
      // compute level of bar graph that is scaled to the  height and the hi and low vals
      // this is needed to accompdate for +/- range
      level = (this->height * (((this->value - this->yminimum) / (this->yrange))));
      // draw the bar graph
      // write a upper and lower bar to minimize flicker cause by blanking out bar and redraw on update
      display.drawRect(this->xpos, this->ypos - this->height, this->width, this->height, SSD1306_WHITE);
      display.fillRect(this->xpos, this->ypos - this->height, this->width, this->height - level,  SSD1306_BLACK);
      display.drawRect(this->xpos, this->ypos - this->height, this->width, this->height, SSD1306_WHITE);
      display.fillRect(this->xpos, this->ypos - level, this->width,  level, SSD1306_WHITE);
      // up until now print sends data to a video buffer NOT the screen
      // this call sends the data to the screen
      display.display();
      break;

      case 'b':

      if (this->redraw) {
        display.clearDisplay();
        this->redraw = false;
        display.fillRect(0, 0,  127 , 16, SSD1306_WHITE);
        display.setTextColor(SSD1306_BLACK, SSD1306_WHITE);
        display.setTextSize(1);
        display.setCursor(2, 4);
        display.println(this->title);
        // draw the text
        
        for (i = 0; i <= this->width; i += this->graphScale) {
          display.drawFastVLine(i + this->xpos , this->ypos ,  5, SSD1306_WHITE);
          // draw lables
          display.setTextSize(1);
          display.setTextColor(SSD1306_WHITE, SSD1306_BLACK);
          display.setCursor(i + this->xpos , this->ypos + 10);
          // addling a small value to eliminate round off errors
          // this val may need to be adjusted
          data =  ( i * (this->xStepSize / this->graphScale)) + this->xminimum + 0.00001;
          display.print(data, this->digit);
        }
      }
      // compute level of bar graph that is scaled to the width and the hi and low vals
      // this is needed to accompdate for +/- range capability
      // draw the bar graph
      // write a upper and lower bar to minimize flicker cause by blanking out bar and redraw on update
      level = (this->width * (((this->value - this->xminimum) / (this->xmaximum - this->xminimum))));
      display.fillRect(this->xpos + level, this->ypos - this->height, this->width - level, this->height,  SSD1306_BLACK);
      display.drawRect(this->xpos, this->ypos - this->height, this->width,  this->height, SSD1306_WHITE);
      display.fillRect(this->xpos, this->ypos - this->height, level,  this->height, SSD1306_WHITE);
      // up until now print sends data to a video buffer NOT the screen
      // this call sends the data to the screen
      display.display();
      break;

      case 'c':
      double temp;
    
      if (this->redraw == true) {
        this->redraw = false;
        display.clearDisplay();
        display.fillRect(0, 0,  127 , 16, SSD1306_WHITE);
        display.setTextColor(SSD1306_BLACK, SSD1306_WHITE);
        display.setTextSize(1);
        display.setCursor(2, 4);
        display.println(title);
        this->ox = (this->count - this->xminimum) * (this->width) / (this->xrange) + this->xpos;
        this->oy = (this->value - this->yminimum) * (- this->height) / (this->yrange) + this->ypos;
        // draw y scale
        display.setTextSize(1);
        display.setTextColor(SSD1306_WHITE, SSD1306_BLACK);
        for ( i = this->yminimum; i <= this->ymaximum; i += this->yStepSize) {
          // compute the transform
          // note my transform funcition is the same as the map function, except the map uses long and we need doubles
          temp =  (i - this->yminimum) * (- this->height) / (this->ymaximum - this->yminimum) + this->ypos;
          if (i == 0) {
            display.drawFastHLine(this->xpos - 3, temp, this->width + 3, SSD1306_WHITE);
          }
          else {
            display.drawFastHLine(this->xpos - 3, temp, 3, SSD1306_WHITE);
          }
          display.setCursor(this->xpos - 27, temp - 3);
          display.println(i, this->digit);
        }
        // draw x scale
        for (i = this->xminimum; i <= this->xmaximum; i += this->xStepSize) {
          // compute the transform
          display.setTextSize(1);
          display.setTextColor(SSD1306_WHITE, SSD1306_BLACK);
          temp =  (i - this->xminimum) * (this->width) / (this->xrange) + this->xpos;
          if (i == 0) {
            display.drawFastVLine(temp, this->ypos - this->height, this->height + 3, SSD1306_WHITE);
          }
          else {
            display.drawFastVLine(temp, this->ypos, 3, SSD1306_WHITE);
          }
          display.setCursor(temp, this->ypos + 6);
          display.println(i, this->digit);
        }
      }
    
      // graph drawn now plot the data
      // the entire plotting code are these few lines...
    
      this->x =  (this->count - this->xminimum) * (this->width) / (this->xrange) + this->xpos;
      this->value =  (this->value - this->yminimum) * (- this->height) / (this->yrange) + this->ypos;
      display.drawLine(this->ox, this->oy, this->x, this->value, SSD1306_WHITE);
      display.drawLine(this->ox, this->oy - 1, this->x, this->value - 1, SSD1306_WHITE);
      this->ox = this->x;
      this->oy = this->value;
    
      // up until now print sends data to a video buffer NOT the screen
      // this call sends the data to the screen
      display.display();
      this->count += 1;
      if(this->ox >= (this->xpos + this->width)){
        this->redraw = true;
        this->count = xminimum;
      }
    }
  }

  void redrawFlag(){ // Activates the redraw bool to get the graph printed correctly
    this->redraw = true;
  }

  void setPreviousScreen(int prev){
    this->previousScreen = prev;
  }

  void setPreviousContentType(int prev){
    this->previousContentType = prev;
  }

  int getPreviousScreen(){
    int prev = this->previousScreen;
    return prev;
  }

  int getPreviousContentType(){
    int prev = this->previousContentType;
    return prev;
  }

  void assignValue(double value){
    this->value = value;
  }

  void reset(){
    this->x = 0;
  }
  
};

class Modifier{       //ContentType (2)
  private:

  String title;
  int *value;
  int max;
  int min;
  int interval;

  int previousScreen = 0;
  int previousContentType = 0;

  public:

  void configure(String title, int *value, int max, int min, int interval){
    this->value = value;
    this->max = max;
    this->min = min;
    this->interval = interval;
  }

  void drawModifier(){
    display.clearDisplay();
    display.fillRect(0, 0,  127 , 16, SSD1306_WHITE);
    display.setTextColor(SSD1306_BLACK);
    display.setTextSize(1);
    display.setCursor(2, 4);
    display.println(this->title);

    display.setTextColor(SSD1306_WHITE);
    display.setTextSize(3);
    display.setCursor(2, ((DISP_HEIGHT - 16 - 20)/2) + 20);
    display.println(*this->value);
  }

  void increaseValue(){
    if((*this->value + interval) <= this->max){
      *this->value += interval;
    }
  }

  void decreaseValue(){
    if((*this->value - interval) >= this->min){
      *this->value -= interval;
    }
  }

  void setPreviousScreen(int prev){
    this->previousScreen = prev;
  }

  void setPreviousContentType(int prev){
    this->previousContentType = prev;
  }

  int getPreviousScreen(){
    int prev = this->previousScreen;
    return prev;
  }

  int getPreviousContentType(){
    int prev = this->previousContentType;
    return prev;
  }
};

class Screen{
  private:
  
  Menu menu[MAX_MENUS];  //Array of menus to use
  Graph graph[MAX_GRAPHS];  //Array of graphs to use
  Modifier modifier[MAX_MODIFIERS];  //Array of modifiers to use

  int counterM = 0;        //Number of menus created
  int counterG = 0;        //Number of graphs created
  int counterMod = 0;
  bool redraw = true;      //Redraw interface for when there is a change of screen
  int currentScreen = 0;
  int contentType = 0;

  public:


  void configure(bool fullsetting){  //This method allows the configuration of the display when the parameter is true. Otherwise only prints a greeting message.
    if(fullsetting){
      //Adafruit_SSD1306 display(DISP_WIDTH, DISP_HEIGHT, &Wire, -1);
      Serial.begin(115200);
      if (!display.begin(SSD1306_SWITCHCAPVCC, ADDRESS)) {
  #ifdef __DEBUG__
        Serial.println("Display not found!");
  #endif
        while (true);
      }
    }
    display.clearDisplay();
  
    // Text size
    display.setTextSize(2);
    // Text color
    display.setTextColor(SSD1306_WHITE);
    // Text position
  
    display.setCursor(25, 20);
    display.println("Welcome");
    
    
    display.setTextSize(1);
  
    display.display();
    delay(5000);
  }

  void createMenu(int sizex, int sizey){   //This method is used for the creation of a menu
    this->menu[counterM].configure(sizex, sizey);
    this->counterM++;
  }

  void createOption(int menuIndex, String content, bool destinationTypeMenu, int destinationIndex){  //this method should be used for creating an option in a menu
    this->menu[menuIndex].createOption(content, destinationTypeMenu, destinationIndex);
  }

  void createVGraph(String title, double xpos, double ypos, double width, double height,
  double yminimum, double ymaximum, double yStepSize, int digit){   //this method calls the configure() of graph for a vertical graph
    this->graph[counterG].configure(title, 'a', xpos, ypos, width, height, yminimum, ymaximum, 0, 0, yStepSize, 0, digit);
    this->counterG++;
  }

  void createHGraph(String title, double xpos, double ypos, double width, double height, 
  double xminimum, double xmaximum, double xStepSize, int digit){  //this method calls the configure() of graph for a horizontal graph
    this->graph[counterG].configure(title, 'b', xpos, ypos, width, height, 0, 0, xminimum, xmaximum, 0, xStepSize, digit);
    counterG++;
  }

  void createCGraph(String title, double xpos, double ypos, double width, double height,
  double yminimum, double ymaximum, double xminimum, double xmaximum, double yStepSize, double xStepSize, int digit){  //this method calls the configure() of graph for a cartesian chart
    this->graph[counterG].configure(title, 'c', xpos, ypos, width, height, yminimum, ymaximum, xminimum, xmaximum, yStepSize, xStepSize, digit);
    counterG++;
  }

  void createModifier(String title, int *value, int max, int min, int interval){   //This method is used for the creation of a menu
    this->modifier[counterMod].configure(title, value, max, min, interval);
    this->counterMod++;
  }

/*  
  void redrawFlag(){
    this->redraw = true;
  }
*/

//The following method is used for assingning a value to a graph
//This can be avoided using pointers to the variable to plot in the graph
  void graphAssignValue(int graphIndex, double value){
    this->graph[graphIndex].assignValue(value);
    this->redraw = true;
  }

//This method controls the whole interface, it needs to be called within a loop
  void control(){
    if (redraw){
      if (contentType == 0){
        menu[currentScreen].drawMenu();
      }
      else if (contentType == 1){
        graph[currentScreen].drawGraph();
      }
      this->redraw = false;
    }
  }

//The following two methods allow the change in position of the cursor
  void increasePos(){
    if(this->menu[this->currentScreen].extractPos() < this->menu[this->currentScreen].extractOptNumber() - 1)
      this->menu[this->currentScreen].increasePos();
  }

  void decreasePos(){
    if(this->menu[this->currentScreen].extractPos() > 0)
      this->menu[this->currentScreen].decreasePos();
  }
  
//This method lets the user go into another screen by selecting an option
  void goTo(){
    if(this->contentType == 0){
      int newScreen = this->menu[this->currentScreen].extractDestinationIndex();
      int newContentType = this->menu[this->currentScreen].extractDestinationType();
      if (newContentType == 0){
        this->menu[newScreen].setPreviousScreen(this->currentScreen);
        this->menu[newScreen].setPreviousContentType(this->contentType);
      }
      else if(newContentType == 1){
        this->graph[newScreen].setPreviousScreen(this->currentScreen);
        this->graph[newScreen].setPreviousContentType(this->contentType);
        this->graph[newScreen].reset();
        this->graph[newScreen].redrawFlag();
      }
      else if(newContentType == 2){

      }
      this->contentType = newContentType;
      this->currentScreen = newScreen;
      this->redraw = true;
    }
  }

  void goBack(){
    if(contentType == 0){
      //Gets indexes from previous screen saved in actual screen if it is a menu, and sets them as the current indexes
      this->currentScreen = this->menu[this->currentScreen].getPreviousScreen();
      this->contentType = this->menu[this->currentScreen].getPreviousContentType();
    }
    else if(contentType == 1){
      //Gets indexes from previous screen saved in actual screen if it is a graph, and sets them as the current indexes
      this->currentScreen = this->graph[this->currentScreen].getPreviousScreen();
      this->contentType = this->graph[this->currentScreen].getPreviousContentType();
    }
  }

//These methods control the plus and minus button actions
  void plusAction(){
    if(contentType == 0){
      increasePos();
    }
  }

  void minusAction(){
    if(contentType == 0){
      decreasePos();
    }
  }
  
};

class Keyboard{
  private:

  byte goTo;
  byte goBack;
  byte plus;
  byte minus;
  byte debounceTime;

  Screen *screen;

  public:

//Keyboard constructor
  Keyboard(byte goTo, byte goBack, byte plus, byte minus, byte debounceTime, Screen * screen){
    this->goTo = goTo;
    this->goBack = goBack;
    this->plus = plus;
    this->minus = minus;
    this->debounceTime = debounceTime;

    this->screen = screen;

    pinMode(goTo, INPUT_PULLUP);
    pinMode(goBack, INPUT_PULLUP);
    pinMode(plus, INPUT_PULLUP);
    pinMode(minus, INPUT_PULLUP);
  }
//Debouncing functions
  void checkGoTo(){
    static char cont;
    if(digitalRead(this->goTo) == LOW)
      cont++;
    else
      cont = 0;
    if(cont == debounceTime/REFRESH){
      this->screen->goTo();
    }
  }
  
  void checkGoBack(){
    static char cont;
    if(digitalRead(this->goBack) == LOW){
      cont++;
    }
    else
      cont = 0;
    if(cont == debounceTime/REFRESH){
      this->screen->goBack();
    }
  }

  void checkPlus(){
    static char cont;
    if(digitalRead(this->plus) == LOW)
      cont++;
    else
      cont = 0;
    if(cont == debounceTime/REFRESH){
      this->screen->plusAction();
    }
  }

  void checkMinus(){
    static char cont;
    if(digitalRead(this->minus) == LOW)
      cont++;
    else
      cont = 0;
    if(cont == debounceTime/REFRESH){
      this->screen->minusAction();
    }
  }

// All buttons are checked with this method
  void control(){
    this->checkGoTo();
    this->checkGoBack();
    this->checkPlus();
    this->checkMinus();
  }
};

int i = 0;

Screen screen;
Keyboard keyboard(13, 12, 14, 27, 30, &screen);

void setup(){
  screen.configure(true);
  
  screen.createMenu(128, 13);             //Menu 0
  screen.createMenu(128, 13);             //Menu 1

  /*String title, char graphType, double xpos, double ypos, double width, double height,
  double yminimum, double ymaximum, double xminimum, double xmaximum, double yStepSize, double xStepSize, double digit*/
  
  screen.createVGraph("Grafica 1", 25, 60, 40, 40, 0, 100, 10, 0);               //Graph 0
  screen.createHGraph("Grafica 2", 10, 40, 100, 20, 0, 100, 10, 0);              //Graph 1
  screen.createCGraph("Grafica 3", 30, 50, 75, 30, 0, 100, 0, 1000, 25, 250, 0);   //Graph 2
  
  screen.createOption(0, "Vertical graph", 1, 0);
  //Creates the first option in Menu 0, directing to a graph (contentType = 1 (Graph)), 0 (Graph 0)
  screen.createOption(0, "Horizontal graph", 1, 1);       
  screen.createOption(0, "Cartesian graph", 1, 2);
  screen.createOption(0, "Extra option", 0, 1);

  screen.createOption(1, "Test", 1, 3);
  screen.createOption(1, "Working?", 1, 4);

//  screen.increasePos();
//  screen.increasePos();
//  screen.goTo();
//  screen.graphAssignValue(2, 50);
//  screen.goBack();
//  screen.increasePos();
//  screen.goTo();
//  screen.goBack();
//  screen.decreasePos();
}

void loop(){
  screen.control();            //Controls the screen and redraws if needed
  keyboard.control();

  if(i <= 100){
    screen.graphAssignValue(1, i);    //Assigning a demo value to Graph 1
    screen.graphAssignValue(2, i);    //Assigning a demo value to Graph 2
    i++;
  }
  else
    i = 0;

  delay(REFRESH);                   //Refresh time (approx)
}