const uint8_t rows_pins[]    = {  7,  8,  9 };
const uint8_t columns_pins[] = { 12, 11, 10 };

struct symbol_t
{
  //uint8_t r0 : 3;
  //uint8_t r1 : 3;
  //uint8_t r2 : 3;
  uint16_t r : 9;
};

const symbol_t symbols[] =
{
  // X
  {
    0b101,
    0b010,
    0b101
  },

  // T
  {
    0b111,
    0b010,
    0b010
  },

  // square
  {
    0b111,
    0b101,
    0b111
  }
};
/*
const uint16_t symbols[] =
{
//  000111222 row id
//  012012012 column id
  0b101010101, // X
  0b111010010, // T
  0b010101010; // o
  0b111101111, // square
  0b111111111, // all on
}*/

void setup()
{
  Serial.begin( 115200 );

  Serial.println( sizeof( symbols[0] ) );
  Serial.println( symbols[0][0] );

  for ( uint8_t i = 0; i < 3; ++i )
  {
    const uint8_t pin = rows_pins[i];
    pinMode( pin, OUTPUT );
    digitalWrite( pin, LOW );
  }

  for ( uint8_t i = 0; i < 3; ++i )
  {
    const uint8_t pin = columns_pins[i];
    pinMode( pin, OUTPUT );
    digitalWrite( pin, LOW );
  }
}

void loop()
{
  
}