#define CLK 3
#define DAT 4
#define WAIT 1

uint8_t str[] = "Hello PIC!!";

void setup()
{
  pinMode(CLK, OUTPUT);
  pinMode(DAT, OUTPUT);
  digitalWrite(CLK, HIGH);
  digitalWrite(DAT, HIGH);
  delay(50);
}

void loop()
{
  sendChar(0x80); //lcd_setCursor(0, 0);
  for(int i=0; i<8; i++)
    sendChar(str[i]);
  sendChar(0x90); //lcd_setCursor(0, 1);
  for(int i=8; i<sizeof(str); i++)
    sendChar(str[i]);

  while(true);
}

void sendChar(uint8_t chr)
{
  digitalWrite(CLK, LOW); //スタートビット
  delay(WAIT);
  digitalWrite(CLK, HIGH);
  delay(WAIT);

  for(int n = 0; n < 8; n++)
  {
    digitalWrite(DAT, (chr >> n) & 1);
    delay(WAIT);
    digitalWrite(CLK, LOW);
    delay(WAIT);
    digitalWrite(CLK, HIGH);
  }
}