AVR 에서 UART 전송시 사용되는 HEX To CHAR 변환샘플

// Hex or Decimal을
//ASCII로 변환하는 루틴 
// Ex) 숫자 3은 ASCII Code가 0x32임
void NumToASCII( unsigned char value )
{
 unsigned char buff;        
 buff = value & 0x0F;
 if( buff < 0xA )
 ASCII[1] = buff + 0x30; // if value<10
 else
 ASCII[1] = buff + 0x37; // if value>10
 buff = value & 0xF0;
 buff >>= 4;
 if( buff < 0xA )
 ASCII[0] = buff + 0x30; // if value<10
 else
 ASCII[0] = buff + 0x37; // if value>10
}

// ex2
char tmp[2] = "";
sprintf(tmp, "%02X", 0xF);
printf("%c%c\n", tmp[0], tmp[1]);
 

//ex3
unsigned char c = 0x1A;

char first = (0xf0 & c) >> 4;
char second = (0x0f & c);


결과는 다 같고..

두번째 예제정도면 충분할듯;

// Char, Hex간 변환

void Char2Hex(unsigned char ch, char* szHex)
{
 static unsigned char saucHex[] = "0123456789ABCDEF";
 szHex[0] = saucHex[ch >> 4];
 szHex[1] = saucHex[ch&0xF];
 szHex[2] = 0;
}

//Function to convert a Hex string of length 2 to an unsigned char
bool Hex2Char(char const* szHex, unsigned char& rch)
{
 if(*szHex >= '0' && *szHex <= '9')
  rch = *szHex - '0';
 else if(*szHex >= 'A' && *szHex <= 'F')
  rch = *szHex - 55; //-'A' + 10
 else
  //Is not really a Hex string
  return false;
 szHex++;
 if(*szHex >= '0' && *szHex <= '9')
  (rch <<= 4) += *szHex - '0';
 else if(*szHex >= 'A' && *szHex <= 'F')
  (rch <<= 4) += *szHex - 55; //-'A' + 10;
 else
  //Is not really a Hex string
  return false;
 return true;
}

//Function to convert binary string to hex string
void Binary2Hex(unsigned char const* pucBinStr, int iBinSize, char* pszHexStr)
{
 int i;
 char szHex[3];
 unsigned char const* pucBinStr1 = pucBinStr;
 *pszHexStr = 0;
 for(i=0; i<iBinSize; i++,pucBinStr1++)
 {
  Char2Hex(*pucBinStr1, szHex);
  strcat(pszHexStr, szHex);
 }
}

//Function to convert hex string to binary string
bool Hex2Binary(char const* pszHexStr, unsigned char* pucBinStr, int iBinSize)
{
 int i;
 unsigned char ch;
 for(i=0; i<iBinSize; i++,pszHexStr+=2,pucBinStr++)
 {
  if(false == Hex2Char(pszHexStr, ch))
   return false;
  *pucBinStr = ch;
 }
 return true;
}

출처 : http://enlog.tistory.com/entry/char-hex%EA%B0%84-%EB%B3%80%ED%99%98