Dot matrix - code
Help me by sharing this post

This is the code for the dot matrix with Bluetooth project. Ok, before you close the case and add the Bluetooth module, go below and downlaod the full code. You will need to download the library as well and install it to the Arduino IDE. You have the library on that same link below. Once you upload the code, go to next step and get the Android app and install it to your smartphone.



schematic dot matrix display Arduino



/*  Dot LED matrix display with Bluetooth and RTC by ELECTRONOOBS
 *  DATE: 15/09/2019
 *  Tutorial: https://electronoobs.com/eng_arduino_tut106.php
 *  Video: https://www.youtube.com/watch?v=4_DX7_N_Jx0
 *  Schematic: https://electronoobs.com/eng_arduino_tut106_sch1.php
 *  Code: https://electronoobs.com/eng_arduino_tut106_code1.php
 *  App: https://electronoobs.com/eng_arduino_tut106_app1.php
 */

#include "MaxMatrix.h"              //Downlaod here: https://electronoobs.com/eng_arduino_max_matrix.php
#include "avr/pgmspace.h"         
#include <DS3231.h>                 //Downlaod here: https://electronoobs.com/eng_arduino_ds3231.php       


PROGMEM const unsigned char CH[] = {
  3, 8, B00000000, B00000000, B00000000, B00000000, B00000000, // space
  1, 8, B01011111, B00000000, B00000000, B00000000, B00000000, // !
  3, 8, B00000011, B00000000, B00000011, B00000000, B00000000, // "
  5, 8, B00010100, B00111110, B00010100, B00111110, B00010100, // #
  4, 8, B00100100, B01101010, B00101011, B00010010, B00000000, // $
  5, 8, B01100011, B00010011, B00001000, B01100100, B01100011, // %
  5, 8, B00110110, B01001001, B01010110, B00100000, B01010000, // &
  1, 8, B00000011, B00000000, B00000000, B00000000, B00000000, // '
  3, 8, B00011100, B00100010, B01000001, B00000000, B00000000, // (
  3, 8, B01000001, B00100010, B00011100, B00000000, B00000000, // )
  5, 8, B00101000, B00011000, B00001110, B00011000, B00101000, // *
  5, 8, B00001000, B00001000, B00111110, B00001000, B00001000, // +
  2, 8, B10110000, B01110000, B00000000, B00000000, B00000000, // ,
  4, 8, B00001000, B00001000, B00001000, B00001000, B00000000, // -
  2, 8, B01100000, B01100000, B00000000, B00000000, B00000000, // .
  4, 8, B01100000, B00011000, B00000110, B00000001, B00000000, // /
  4, 8, B00111110, B01000001, B01000001, B00111110, B00000000, // 0
  3, 8, B01000010, B01111111, B01000000, B00000000, B00000000, // 1
  4, 8, B01100010, B01010001, B01001001, B01000110, B00000000, // 2
  4, 8, B00100010, B01000001, B01001001, B00110110, B00000000, // 3
  4, 8, B00011000, B00010100, B00010010, B01111111, B00000000, // 4
  4, 8, B00100111, B01000101, B01000101, B00111001, B00000000, // 5
  4, 8, B00111110, B01001001, B01001001, B00110000, B00000000, // 6
  4, 8, B01100001, B00010001, B00001001, B00000111, B00000000, // 7
  4, 8, B00110110, B01001001, B01001001, B00110110, B00000000, // 8
  4, 8, B00000110, B01001001, B01001001, B00111110, B00000000, // 9
  2, 8, B01010000, B00000000, B00000000, B00000000, B00000000, // :
  2, 8, B10000000, B01010000, B00000000, B00000000, B00000000, // ;
  3, 8, B00010000, B00101000, B01000100, B00000000, B00000000, // <
  3, 8, B00010100, B00010100, B00010100, B00000000, B00000000, // =
  3, 8, B01000100, B00101000, B00010000, B00000000, B00000000, // >
  4, 8, B00000010, B01011001, B00001001, B00000110, B00000000, // ?
  5, 8, B00111110, B01001001, B01010101, B01011101, B00001110, // @
  4, 8, B01111110, B00010001, B00010001, B01111110, B00000000, // A
  4, 8, B01111111, B01001001, B01001001, B00110110, B00000000, // B
  4, 8, B00111110, B01000001, B01000001, B00100010, B00000000, // C
  4, 8, B01111111, B01000001, B01000001, B00111110, B00000000, // D
  4, 8, B01111111, B01001001, B01001001, B01000001, B00000000, // E
  4, 8, B01111111, B00001001, B00001001, B00000001, B00000000, // F
  4, 8, B00111110, B01000001, B01001001, B01111010, B00000000, // G
  4, 8, B01111111, B00001000, B00001000, B01111111, B00000000, // H
  3, 8, B01000001, B01111111, B01000001, B00000000, B00000000, // I
  4, 8, B00110000, B01000000, B01000001, B00111111, B00000000, // J
  4, 8, B01111111, B00001000, B00010100, B01100011, B00000000, // K
  4, 8, B01111111, B01000000, B01000000, B01000000, B00000000, // L
  5, 8, B01111111, B00000010, B00001100, B00000010, B01111111, // M
  5, 8, B01111111, B00000100, B00001000, B00010000, B01111111, // N
  4, 8, B00111110, B01000001, B01000001, B00111110, B00000000, // O
  4, 8, B01111111, B00001001, B00001001, B00000110, B00000000, // P
  4, 8, B00111110, B01000001, B01000001, B10111110, B00000000, // Q
  4, 8, B01111111, B00001001, B00001001, B01110110, B00000000, // R
  4, 8, B01000110, B01001001, B01001001, B00110010, B00000000, // S
  5, 8, B00000001, B00000001, B01111111, B00000001, B00000001, // T
  4, 8, B00111111, B01000000, B01000000, B00111111, B00000000, // U
  5, 8, B00001111, B00110000, B01000000, B00110000, B00001111, // V
  5, 8, B00111111, B01000000, B00111000, B01000000, B00111111, // W
  5, 8, B01100011, B00010100, B00001000, B00010100, B01100011, // X
  5, 8, B00000111, B00001000, B01110000, B00001000, B00000111, // Y
  4, 8, B01100001, B01010001, B01001001, B01000111, B00000000, // Z
  2, 8, B01111111, B01000001, B00000000, B00000000, B00000000, // [
  4, 8, B00000001, B00000110, B00011000, B01100000, B00000000, // \ backslash
  2, 8, B01000001, B01111111, B00000000, B00000000, B00000000, // ]
  3, 8, B00000010, B00000001, B00000010, B00000000, B00000000, // hat
  4, 8, B01000000, B01000000, B01000000, B01000000, B00000000, // _
  2, 8, B00000001, B00000010, B00000000, B00000000, B00000000, // `
  4, 8, B00100000, B01010100, B01010100, B01111000, B00000000, // a
  4, 8, B01111111, B01000100, B01000100, B00111000, B00000000, // b
  4, 8, B00111000, B01000100, B01000100, B00101000, B00000000, // c
  4, 8, B00111000, B01000100, B01000100, B01111111, B00000000, // d
  4, 8, B00111000, B01010100, B01010100, B00011000, B00000000, // e
  3, 8, B00000100, B01111110, B00000101, B00000000, B00000000, // f
  4, 8, B10011000, B10100100, B10100100, B01111000, B00000000, // g
  4, 8, B01111111, B00000100, B00000100, B01111000, B00000000, // h
  3, 8, B01000100, B01111101, B01000000, B00000000, B00000000, // i
  4, 8, B01000000, B10000000, B10000100, B01111101, B00000000, // j
  4, 8, B01111111, B00010000, B00101000, B01000100, B00000000, // k
  3, 8, B01000001, B01111111, B01000000, B00000000, B00000000, // l
  5, 8, B01111100, B00000100, B01111100, B00000100, B01111000, // m
  4, 8, B01111100, B00000100, B00000100, B01111000, B00000000, // n
  4, 8, B00111000, B01000100, B01000100, B00111000, B00000000, // o
  4, 8, B11111100, B00100100, B00100100, B00011000, B00000000, // p
  4, 8, B00011000, B00100100, B00100100, B11111100, B00000000, // q
  4, 8, B01111100, B00001000, B00000100, B00000100, B00000000, // r
  4, 8, B01001000, B01010100, B01010100, B00100100, B00000000, // s
  3, 8, B00000100, B00111111, B01000100, B00000000, B00000000, // t
  4, 8, B00111100, B01000000, B01000000, B01111100, B00000000, // u
  5, 8, B00011100, B00100000, B01000000, B00100000, B00011100, // v
  5, 8, B00111100, B01000000, B00111100, B01000000, B00111100, // w
  5, 8, B01000100, B00101000, B00010000, B00101000, B01000100, // x
  4, 8, B10011100, B10100000, B10100000, B01111100, B00000000, // y
  3, 8, B01100100, B01010100, B01001100, B00000000, B00000000, // z
  3, 8, B00001000, B00110110, B01000001, B00000000, B00000000, // {
  1, 8, B01111111, B00000000, B00000000, B00000000, B00000000, // |
  3, 8, B01000001, B00110110, B00001000, B00000000, B00000000, // }
  4, 8, B00001000, B00000100, B00001000, B00000100, B00000000, // ~
};


// Init the DS3231 using the hardware interface
DS3231  rtc(SDA, SCL);


int data = 11;    // DIN pin of MAX7219 module
int load = 12;    // CS pin of MAX7219 module
int clock = 13;  // CLK pin of MAX7219 module

int maxInUse = 9;  //how many MAX7219 are connected

MaxMatrix m(data, load, clock, maxInUse); // define Library

byte buffer[10];
int string_length = 62;
char string1[100] = "ELECTRONOBS.COM      ";  // Scrolling Text
char string2[100] = "                                                    ";  // Scrolling Text

int i = 0;
int y = 0;
int initial = 0;
const unsigned char initialText[] PROGMEM ={"Open App and send text   "}; //This will be the initial displayed text
String message ="";       //create an empty string to store the future received data 
String prev_message ="";       //create an empty string to store the future received data 
int mode = 1;
int the_delay = 20;
int Brightness = 0;
bool off_once = false;


void setup() {
  Serial.begin(9600);
  rtc.begin();
  delay(20);
  m.init(); // module MAX7219
  m.setIntensity(Brightness); // LED Intensity 0-15
  
  //rtc.setDOW(MONDAY);     // Set Day-of-Week to SUNDAY
  //rtc.setTime(15, 25, 0);     // Set the time to 12:00:00 (24hr format)
  //rtc.setDate(26, 8, 2019);   // Set the date to January 1st, 2014
}

void loop() {
  


  ///////////////////////////////////////////////////////////////
  while(Serial.available() > 0)
  {    
    prev_message = message;
    message = Serial.readString(); //Store the bluetooth received text
    //Serial.println(message.length());
    Serial.println(message);
    if(message.length() < string_length)
    {
      if(message[0] == 's' && message[1] == 'h' && message[2] == 'o' && message[3] == 'w' &&
      message[4] == '_' && message[5] == 'h' && message[6] == 'o' && message[7] == 'u' && message[8] == 'r')
      {        
        mode = 3;
        while(i < string_length)
        {
          string2[i] = '\0';
          i = i + 1;
        }
      i = 0;
      }//End mode 3 (receive show only hour)

      
      else if(message[0] == 's' && message[1] == 'h' && message[2] == 'o' && message[3] == 'w' &&
      message[4] == '_' && message[5] == 't' && message[6] == 'i' && message[7] == 'm' && message[8] == 'e')
      {
        mode = 2;
        while(i < string_length)
        {
          string2[i] = '\0';
          i = i + 1;
        }
        i = 0;
      }//End mode 2 (receive show full date)

      else if(message[0] == 'd' && message[1] == 'e' && message[2] == 'l' && message[3] == 'a' &&
      message[4] == 'y' && message[5] == '=')
      { 
        String delay_value = String (message[6]) + String (message[7]) + String (message[8]);
        the_delay = delay_value.toInt();
        //Serial.println(the_delay);
        message = prev_message;
      }//End (receive delay from BT)

      else if(message[0] == 'b' && message[1] == 'r' && message[2] == 'i' && message[3] == 'g' &&
      message[4] == 'h' && message[5] == 't' && message[6] == '=')
      { 
        String brightness_value = String (message[7]) + String (message[8]);
        Brightness = brightness_value.toInt();
        //Serial.println(Brightness);
        if(Brightness > 15)
        {
          Brightness = 15;
        }
        if(Brightness < 1)
        {
          Brightness = 1;
        }
        m.setIntensity(Brightness); // LED Intensity 0-15
        //Serial.println(the_delay);
        message = prev_message;
      }//End (receive brightness from BT)


      else if(message[0] == 'p' && message[1] == 'w' && message[2] == 'r' && message[3] == '_' &&
      message[4] == 'o' && message[5] == 'f' && message[6] == 'f')
      {        
        mode = 4; 
        off_once = true;
        while(i < string_length)
        {
          string1[i] = '\0';
          i = i + 1;
        }
        i = 0;
      
        message = "Power off!                   ";
        while(i < message.length())
        {  
          string1[i] = char(message[i]);     
          i = i + 1;
        }
        i = 0;
      }//End (receive power off from BT)
      
      else
      {   
        mode = 1;        
        while(i < string_length)
        {
          string1[i] = '\0';
          i = i + 1;
        }
        i = 0;
      
        message = message + "      ";
        while(i < message.length())
        {  
          string1[i] = char(message[i]);     
          i = i + 1;
        }
        i = 0;         
      }//End mode 1 (receive text from BT)
    }//End text below text-length


    else
    {
      message = "Text too long!  Max 62 characters.     ";
        while(i < message.length())
        {  
          string1[i] = char(message[i]);     
          i = i + 1;
        }
        i = 0;        
    }//End text too long
  }//end while Serial.available()
  ///////////////////////////////////////////////////////////////
  

  
  if(mode == 1)
  {
    printStringWithShift(string1, the_delay);  // Send scrolling Text
  }//End print text (mode 1)
  
  if(mode == 2)
  {
    String DAY = rtc.getDOWStr(); 
    String DATE = rtc.getDateStr(); 
    String TIME = rtc.getTimeStr();  
    String HOUR_MINUTE = String(TIME[0])+String(TIME[1])+String(TIME[2])+String(TIME[3])+String(TIME[4]);
    String TEMP = String(rtc.getTemp());   
    String TEMP_1_DEC = String(TEMP[0])+String(TEMP[1])+String(TEMP[2])+String(TEMP[3]);
    String FULL_DATE = DAY + "    " + DATE + "    " + HOUR_MINUTE + "    " + TEMP_1_DEC + "C      ";
    ///////////////////////////////////////////////////////////////
    while(i < FULL_DATE.length())
    {  
      string2[i] = char(FULL_DATE[i]);     
      i = i + 1;
    }
    i = 0;
    ///////////////////////////////////////////////////////////////
    printStringWithShift(string2, the_delay);  // Send scrolling Text
  }//End print full date (mode 2)

  if(mode == 3)
  {       
    String TIME = rtc.getTimeStr();  
    String HOUR_MINUTE = String(TIME[0])+ String(TIME[1])+ String(TIME[2])+ String(TIME[3])+ String(TIME[4]);    
    String FULL_DATE = HOUR_MINUTE + "       ";    
    while(i < FULL_DATE.length())
    {  
      string2[i] = char(FULL_DATE[i]);     
      i = i + 1;
    }
    i = 0;   
    printStringWithShift(string2, the_delay);  // Send scrolling Text
  }//End print only hour (mode 3)


  if(mode == 4)
  {
    if(off_once)
    {
      printStringWithShift(string1, 1);  // Send scrolling Text
      off_once = false;
    }    
  }//End print power off (mode 4)
  

}//end void loop




// Put extracted character on Display
void printCharWithShift(char c, int shift_speed) {
  if (c < 32) return;
  c -= 32;
  memcpy_P(buffer, CH + 7 * c, 7);
  m.writeSprite(maxInUse * 8, 0, buffer);
  m.setColumn(maxInUse * 8 + buffer[0], 0);

  for (int i = 0; i < buffer[0] + 1; i++)
  {
    delay(shift_speed);
    m.shiftLeft(false, false);
  }
}

// Extract characters from Scrolling text
void printStringWithShift(char* s, int shift_speed) {
  while (*s != 0) {
    printCharWithShift(*s, shift_speed);
    s++;
  }
}








yt_link
insta_link
fb_link
twitter_link

Dot matrix


PCBWAY PCB service

PCBWAY PCB service

PCBONLINE PCB service