#define CLK 0
#define DAT 1
#define WAIT 30

#define sendCommand(X) sendChar(X)

#define ADIN 3

int ain;
char str[] = "000";

void setup()
{
  analogReference(DEFAULT);
  pinMode(CLK, OUTPUT);
  pinMode(DAT, OUTPUT);
  digitalWrite(CLK, HIGH);
  digitalWrite(DAT, HIGH);
  delay(200); // LCD準備待ち
}

void loop()
{
  ain = analogRead(ADIN);
  hexString(ain);
  sendCommand(0x80);
  sendStr(str);
  delay(1000);
}

// 10ビット値を16進文字列に
void hexString(int d)
{
  byte b;
  
  for(int i=0; i<3; i++)
  {
    b = (d >> (i * 4)) & 0xf;
    if(b > 9)
      b = b - 10 + 'A';
    else
      b = b + '0';
    str[2 - i] = b;
  }
}

// LCD1文字表示
void sendChar(uint8_t chr)
{
  for(int n = 0; n < 8; n++)
  {
    digitalWrite(DAT, (chr >> n) & 1);
    delayMicroseconds(WAIT);
    digitalWrite(CLK, LOW);
    delayMicroseconds(WAIT);
    digitalWrite(CLK, HIGH);
  }
}

// LCD文字列表示
void sendStr(char* str)
{
  char* p;

  p = str;
  while(*p != 0)
    sendChar(*(p++));
}