// Drawing letters on scope by Hari Wiguna, 2016
// Playing with R-2R Ladder to convert Digital to Analog
// We'll use PORTD because it gives us contiguous 8 bits
// Font courtesy of: http://jared.geek.nz/2014/jan/custom-fonts-for-microcontrollers

const uint8_t fontWidth = 8;
const PROGMEM uint8_t font[]  = {
  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, //  
  0x00,0x5f,0x00,0x00,0x00,0x00,0x00,0x00, // !
  0x00,0x03,0x00,0x03,0x00,0x00,0x00,0x00, // "
  0x0a,0x1f,0x0a,0x1f,0x0a,0x00,0x00,0x00, // #
  0x24,0x2a,0x2a,0x7f,0x2a,0x2a,0x12,0x00, // $
  0x00,0x47,0x25,0x17,0x08,0x74,0x52,0x71, // %
  0x00,0x36,0x49,0x49,0x49,0x41,0x41,0x38, // &
  0x00,0x03,0x00,0x00,0x00,0x00,0x00,0x00, // '
  0x00,0x3e,0x41,0x00,0x00,0x00,0x00,0x00, // (
  0x41,0x3e,0x00,0x00,0x00,0x00,0x00,0x00, // )
  0x04,0x15,0x0e,0x15,0x04,0x00,0x00,0x00, // *
  0x08,0x08,0x3e,0x08,0x08,0x00,0x00,0x00, // +
  0x00,0xc0,0x00,0x00,0x00,0x00,0x00,0x00, // ,
  0x08,0x08,0x08,0x08,0x08,0x00,0x00,0x00, // -
  0x40,0x00,0x00,0x00,0x00,0x00,0x00,0x00, // .
  0x40,0x20,0x10,0x08,0x04,0x02,0x01,0x00, // /
  0x00,0x3e,0x61,0x51,0x49,0x45,0x43,0x3e, // 0
  0x01,0x01,0x7e,0x00,0x00,0x00,0x00,0x00, // 1
  0x00,0x71,0x49,0x49,0x49,0x49,0x49,0x46, // 2
  0x41,0x49,0x49,0x49,0x49,0x49,0x36,0x00, // 3
  0x00,0x0f,0x10,0x10,0x10,0x10,0x10,0x7f, // 4
  0x00,0x4f,0x49,0x49,0x49,0x49,0x49,0x31, // 5
  0x00,0x3e,0x49,0x49,0x49,0x49,0x49,0x30, // 6
  0x01,0x01,0x01,0x01,0x01,0x01,0x7e,0x00, // 7
  0x00,0x36,0x49,0x49,0x49,0x49,0x49,0x36, // 8
  0x00,0x06,0x49,0x49,0x49,0x49,0x49,0x3e, // 9
  0x14,0x00,0x00,0x00,0x00,0x00,0x00,0x00, // :
  0x40,0x34,0x00,0x00,0x00,0x00,0x00,0x00, // ;
  0x08,0x14,0x22,0x00,0x00,0x00,0x00,0x00, // <
  0x14,0x14,0x14,0x14,0x14,0x00,0x00,0x00, // =
  0x22,0x14,0x08,0x00,0x00,0x00,0x00,0x00, // >
  0x00,0x06,0x01,0x01,0x59,0x09,0x09,0x06, // ?
  0x00,0x3e,0x41,0x5d,0x55,0x5d,0x51,0x5e, // @
  0x00,0x7e,0x01,0x09,0x09,0x09,0x09,0x7e, // A
  0x00,0x7f,0x41,0x49,0x49,0x49,0x49,0x36, // B
  0x00,0x3e,0x41,0x41,0x41,0x41,0x41,0x22, // C
  0x00,0x7f,0x41,0x41,0x41,0x41,0x41,0x3e, // D
  0x00,0x3e,0x49,0x49,0x49,0x49,0x49,0x41, // E
  0x00,0x7e,0x09,0x09,0x09,0x09,0x09,0x01, // F
  0x00,0x3e,0x41,0x49,0x49,0x49,0x49,0x79, // G
  0x00,0x7f,0x08,0x08,0x08,0x08,0x08,0x7f, // H
  0x00,0x7f,0x00,0x00,0x00,0x00,0x00,0x00, // I
  0x00,0x38,0x40,0x40,0x41,0x41,0x41,0x3f, // J
  0x00,0x7f,0x08,0x08,0x08,0x0c,0x0a,0x71, // K
  0x00,0x3f,0x40,0x40,0x40,0x40,0x40,0x40, // L
  0x00,0x7e,0x01,0x01,0x7e,0x01,0x01,0x7e, // M
  0x00,0x7e,0x01,0x01,0x3e,0x40,0x40,0x3f, // N
  0x00,0x3e,0x41,0x41,0x41,0x41,0x41,0x3e, // O
  0x00,0x7e,0x09,0x09,0x09,0x09,0x09,0x06, // P
  0x00,0x3e,0x41,0x41,0x71,0x51,0x51,0x7e, // Q
  0x00,0x7e,0x01,0x31,0x49,0x49,0x49,0x46, // R
  0x00,0x46,0x49,0x49,0x49,0x49,0x49,0x31, // S
  0x01,0x01,0x01,0x7f,0x01,0x01,0x01,0x00, // T
  0x00,0x3f,0x40,0x40,0x40,0x40,0x40,0x3f, // U
  0x00,0x0f,0x10,0x20,0x40,0x20,0x10,0x0f, // V
  0x00,0x3f,0x40,0x40,0x3f,0x40,0x40,0x3f, // W
  0x00,0x63,0x14,0x08,0x08,0x08,0x14,0x63, // X
  0x00,0x07,0x08,0x08,0x78,0x08,0x08,0x07, // Y
  0x00,0x71,0x49,0x49,0x49,0x49,0x49,0x47, // Z
  0x00,0x7f,0x41,0x00,0x00,0x00,0x00,0x00, // [
  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, // "\"
  0x41,0x7f,0x00,0x00,0x00,0x00,0x00,0x00, // ]
  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, // ^
  0x40,0x40,0x40,0x40,0x40,0x40,0x40,0x00, // _
  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, // `
  0x00,0x7e,0x01,0x09,0x09,0x09,0x09,0x7e, // A
  0x00,0x7f,0x41,0x49,0x49,0x49,0x49,0x36, // B
  0x00,0x3e,0x41,0x41,0x41,0x41,0x41,0x22, // C
  0x00,0x7f,0x41,0x41,0x41,0x41,0x41,0x3e, // D
  0x00,0x3e,0x49,0x49,0x49,0x49,0x49,0x41, // E
  0x00,0x7e,0x09,0x09,0x09,0x09,0x09,0x01, // F
  0x00,0x3e,0x41,0x49,0x49,0x49,0x49,0x79, // G
  0x00,0x7f,0x08,0x08,0x08,0x08,0x08,0x7f, // H
  0x00,0x7f,0x00,0x00,0x00,0x00,0x00,0x00, // I
  0x00,0x38,0x40,0x40,0x41,0x41,0x41,0x3f, // J
  0x00,0x7f,0x08,0x08,0x08,0x0c,0x0a,0x71, // K
  0x00,0x3f,0x40,0x40,0x40,0x40,0x40,0x40, // L
  0x00,0x7e,0x01,0x01,0x7e,0x01,0x01,0x7e, // M
  0x00,0x7e,0x01,0x01,0x3e,0x40,0x40,0x3f, // N
  0x00,0x3e,0x41,0x41,0x41,0x41,0x41,0x3e, // O
  0x00,0x7e,0x09,0x09,0x09,0x09,0x09,0x06, // P
  0x00,0x3e,0x41,0x41,0x71,0x51,0x51,0x7e, // Q
  0x00,0x7e,0x01,0x31,0x49,0x49,0x49,0x46, // R
  0x00,0x46,0x49,0x49,0x49,0x49,0x49,0x31, // S
  0x01,0x01,0x01,0x7f,0x01,0x01,0x01,0x00, // T
  0x00,0x3f,0x40,0x40,0x40,0x40,0x40,0x3f, // U
  0x00,0x0f,0x10,0x20,0x40,0x20,0x10,0x0f, // V
  0x00,0x3f,0x40,0x40,0x3f,0x40,0x40,0x3f, // W
  0x00,0x63,0x14,0x08,0x08,0x08,0x14,0x63, // X
  0x00,0x07,0x08,0x08,0x78,0x08,0x08,0x07, // Y
  0x00,0x71,0x49,0x49,0x49,0x49,0x49,0x47, // Z
  0x08,0x36,0x41,0x00,0x00,0x00,0x00,0x00, // {
  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00, // |
  0x41,0x36,0x08,0x00,0x00,0x00,0x00,0x00, // }
  0x02,0x01,0x01,0x02,0x02,0x01,0x00,0x00, // ~
  0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
};

char topWord[] =    " HELLO ";
char bottomWord[] = "YouTube";

void setup() {
  DDRD = B11111111; // Set all bits of PORTD as output
}

void loop() {
  MultiChar();
}

void MultiChar()
{
  int horizUnit = 90;
  PORTD = 250;
  
  for (uint8_t i = 0; i < sizeof(topWord) - 1; i++)
  {
    for (uint8_t x = 0; x < fontWidth; x++)
    {
      for (uint8_t r = 0; r < 2; r++)
      {
        int ch = ((r == 0) ? bottomWord[i] : topWord[i]) - ' ';
        uint8_t rowOffset = 80 * r;
        uint8_t bitAnalogValue = 40 + rowOffset;
        unsigned char vertByte = pgm_read_byte_near(font + ch*8 + x);
        for (uint8_t y = 0; y <= 7; y++)
        {
          bitAnalogValue += 7;
          if (bitRead(vertByte, 7 - y)) PORTD = bitAnalogValue;// else PORTD = 0;
          delayMicroseconds(horizUnit);
        }
      }
    }
    PORTD = 0;  delayMicroseconds(500);
  }
  delay(20);
}