/********************************************************************************
 
  * Interfacing MAX7219 LED dot matrix display with Arduino - Text scroll example.
   * This is a free software with NO WARRANTY.
    * http://simple-circuit.com/
     
     /********************************************************************************/
      
      #include <MD_Parola.h>     // include MajicDesigns Parola library
      #include <MD_MAX72xx.h>    // include MajicDesigns MAX72xx LED matrix library
      #include <SPI.h>           // include Arduino SPI library
       
       #define HARDWARE_TYPE MD_MAX72XX::FC16_HW   // this line defines our dot matrix hardware type (FC-16)
       #define MAX_DEVICES 4                       // define number of total cascaded modules
        
        #define CS_PIN    10   // define CS (Chip Select) pin
         
         MD_Parola display = MD_Parola(HARDWARE_TYPE, CS_PIN, MAX_DEVICES);
          
          #define POTPIN   A0   // define speed control potentiometer output pin connection
           
           uint8_t scrollSpeed = 100;    // set initial scroll speed, can be a value between 10 (max) and 150 (min)
           textEffect_t scrollEffect  = PA_SCROLL_RIGHT;  // scroll direction, right-to-left direction
           textPosition_t scrollAlign = PA_RIGHT;         // scroll align
           uint16_t scrollPause = 50;                  // scroll pause in milliseconds
            
            // setup function
            void setup(void) 
            {
              // initialize the dot matrix display
                display.begin();
                   // set the intensity (brightness) of the display (choose a number between 0 and 15)
                     display.setIntensity(9);
                       // clear the whole display
                         display.displayClear();
                          
                            // print text on the display
                              display.displayText("HAPPY LIFE", scrollAlign, scrollSpeed, scrollPause, scrollEffect, scrollEffect);
                              }
                               
                               // main loop function
                               void loop(void) 
                               { 
                                 uint16_t an = analogRead(POTPIN);    // read analog data from potentiometer output
                                  
                                    int16_t speed = map(an, 0, 1023, 100, 10);  // map previous value between 150 & 10 (min & max speed)
                                     
                                       if ( speed != display.getSpeed() )   // check if speed changed
                                           display.setSpeed(speed);           // set new scrolling speed
                                            
                                              if (display.displayAnimate()) {    // animate the display
                                                  display.displayReset();          // reset the current animation
                                                    }
                                                     
                                                     }
                                                      
                                                      // end of code.