Arduino Tutorial for Beginners – LED Matrix With Arduino

main.c

#define ROW_1 2
#define ROW_2 3
#define ROW_3 4
#define ROW_4 5
#define ROW_5 6
#define ROW_6 7
#define ROW_7 8
#define ROW_8 9

#define COL_1 10
#define COL_2 11
#define COL_3 12
#define COL_4 13
#define COL_5 A0
#define COL_6 A1
#define COL_7 A2
#define COL_8 A3

const byte rows[] = {
    ROW_1, ROW_2, ROW_3, ROW_4, ROW_5, ROW_6, ROW_7, ROW_8
};

byte A[] = { B00011000, B00111100, B01100110, B01100110, B01111110, B01111110, B01100110, B01100110 };
byte B[] = { B01111100, B01100110, B01100110, B01111100, B01111110, B01100110, B01100110, B01111100 };
byte C[] = { B00111110, B01111110, B01100000, B01100000, B01100000, B01100000, B01111110, B00111110 };
byte D[] = { B01111000, B01111100, B01100110, B01100110, B01100110, B01100110, B01111100, B01111000 };
byte E[] = { B01111110, B01111110, B01100000, B01111110, B01111110, B01100000, B01111110, B01111110 };
byte F[] = { B01111110, B01111110, B01100000, B01111100, B01111100, B01100000, B01100000, B01100000 };
byte G[] = { B00111000, B01111100, B01100100, B01100000, B01101110, B01100100, B01111100, B00111000 };
byte H[] = { B01100110, B01100110, B01100110, B01111110, B01111110, B01100110, B01100110, B01100110 };
byte I[] = { B01111110, B01111110, B00011000, B00011000, B00011000, B00011000, B01111110, B01111110 };
byte J[] = { B01111110, B01111110, B00011000, B00011000, B00011000, B00011000, B01111000, B01110000 };
byte K[] = { B01100110, B01101100, B01111000, B01110000, B01110000, B01111000, B01101100, B01100110 };
byte L[] = { B01100000, B01100000, B01100000, B01100000, B01100000, B01100000, B01111110, B01111110 };
byte M[] = { B01000010, B01100110, B01111110, B01011010, B01000010, B01000010, B01000010, B01000010 };
byte N[] = { B01000110, B01100110, B01100110, B01110110, B01111110, B01101110, B01100110, B01100110 };
byte O[] = { B00111100, B01111110, B01100110, B01100110, B01100110, B01100110, B01111110, B00111100 };
byte P[] = { B01111000, B01111100, B01100110, B01100110, B01111100, B01111000, B01100000, B01100000 };
byte Q[] = { B00111100, B01000010, B01000010, B01000010, B01000010, B01001010, B00111100, B00000010 };
byte R[] = { B01111100, B01100110, B01100110, B01101100, B01111000, B01111000, B01101100, B01100110 };
byte S[] = { B00111100, B01111110, B01100000, B01111100, B00111110, B00000110, B01111110, B00111100 }; //{B00111000,B01111100,B01100000,B00110000,B00011000,B00001100,B00111100,B01111000};
byte T[] = { B01111110, B01111110, B00011000, B00011000, B00011000, B00011000, B00011000, B00011000 };
byte U[] = { B01100110, B01100110, B01100110, B01100110, B01100110, B01100110, B01111110, B00111100 };
byte V[] = { B01100110, B01100110, B01100110, B01100110, B01100110, B01100110, B00111100, B00011000 };
byte W[] = { B01000010, B01000010, B01000010, B01000010, B01000010, B01011010, B01011010, B00100100 };
byte X[] = { B01100110, B01100110, B01100110, B00111100, B00011000, B00111100, B01100110, B01100110 };
byte Y[] = { B01100110, B01100110, B01100110, B01111110, B00111100, B00011000, B00011000, B00011000 };
byte Z[] = { B01111110, B01111110, B00000110, B00001100, B00011000, B00110000, B01111110, B01111110 };

byte Zero[] = { B00111100, B01111110, B01100110, B01100110, B01100110, B01100110, B01111110, B00111100 };
byte One[] = { B00011000, B00111000, B01111000, B00011000, B00011000, B00011000, B01111110, B01111110 };
byte Two[] = { B00111100, B01111110, B01000110, B00001100, B00011000, B00110000, B01111110, B01111110 };
byte Three[] = { B01111100, B01111110, B00000110, B00111110, B00111110, B00000110, B01111110, B01111100 };
byte Four[] = { B00001100, B00011100, B00111100, B01101100, B01111110, B01111110, B00001100, B00001100 };
byte Five[] = { B01111110, B01111110, B01100000, B01111100, B00111110, B00000110, B01111110, B01111100 };
byte Six[] = { B00001100, B00011000, B00110000, B01111100, B01111110, B01100110, B01100110, B00111100 };
byte Seven[] = { B01111110, B01111110, B00000110, B00000110, B00001100, B00011000, B00110000, B01100000 };
byte Eight[] = { B00111100, B01100110, B01100110, B00111100, B01111110, B01100110, B01100110, B00111100 };
byte Nine[] = { B00111100, B01100110, B01100110, B01111110, B00111110, B00001100, B00011000, B00110000 };

void setColumns(byte b)
{
    digitalWrite(COL_1, (~b >> 0) & 0x01); // Get the 1st bit: 10000000
    digitalWrite(COL_2, (~b >> 1) & 0x01); // Get the 2nd bit: 01000000
    digitalWrite(COL_3, (~b >> 2) & 0x01); // Get the 3rd bit: 00100000
    digitalWrite(COL_4, (~b >> 3) & 0x01); // Get the 4th bit: 00010000
    digitalWrite(COL_5, (~b >> 4) & 0x01); // Get the 5th bit: 00001000
    digitalWrite(COL_6, (~b >> 5) & 0x01); // Get the 6th bit: 00000100
    digitalWrite(COL_7, (~b >> 6) & 0x01); // Get the 7th bit: 00000010
    digitalWrite(COL_8, (~b >> 7) & 0x01); // Get the 8th bit: 00000001
}

void drawScreen(byte buffer2[])
{
    for (byte i = 0; i < 8; i++) {
        setColumns(buffer2[i]); // Set columns for this specific row

        digitalWrite(rows[i], HIGH);
        delay(2); // Set this to 50 or 100 if you want to see the multiplexing effect!
        digitalWrite(rows[i], LOW);
    }
}

void setup()
{
    // Serial.begin(9600);
    for (byte i = 2; i <= 13; i++)
        pinMode(i, OUTPUT);

    pinMode(A0, OUTPUT);
    pinMode(A1, OUTPUT);
    pinMode(A2, OUTPUT);
    pinMode(A3, OUTPUT);
}

void loop()
{
    drawScreen(A);
}