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crc16_test/crc16.cpp

@@ -0,0 +1,51 @@
+#include "Arduino.h"
+#include "crc16.h"
+
+const unsigned int TABLE[] = {
+    0X0000, 0XC0C1, 0XC181, 0X0140, 0XC301, 0X03C0, 0X0280, 0XC241,
+    0XC601, 0X06C0, 0X0780, 0XC741, 0X0500, 0XC5C1, 0XC481, 0X0440,
+    0XCC01, 0X0CC0, 0X0D80, 0XCD41, 0X0F00, 0XCFC1, 0XCE81, 0X0E40,
+    0X0A00, 0XCAC1, 0XCB81, 0X0B40, 0XC901, 0X09C0, 0X0880, 0XC841,
+    0XD801, 0X18C0, 0X1980, 0XD941, 0X1B00, 0XDBC1, 0XDA81, 0X1A40,
+    0X1E00, 0XDEC1, 0XDF81, 0X1F40, 0XDD01, 0X1DC0, 0X1C80, 0XDC41,
+    0X1400, 0XD4C1, 0XD581, 0X1540, 0XD701, 0X17C0, 0X1680, 0XD641,
+    0XD201, 0X12C0, 0X1380, 0XD341, 0X1100, 0XD1C1, 0XD081, 0X1040,
+    0XF001, 0X30C0, 0X3180, 0XF141, 0X3300, 0XF3C1, 0XF281, 0X3240,
+    0X3600, 0XF6C1, 0XF781, 0X3740, 0XF501, 0X35C0, 0X3480, 0XF441,
+    0X3C00, 0XFCC1, 0XFD81, 0X3D40, 0XFF01, 0X3FC0, 0X3E80, 0XFE41,
+    0XFA01, 0X3AC0, 0X3B80, 0XFB41, 0X3900, 0XF9C1, 0XF881, 0X3840,
+    0X2800, 0XE8C1, 0XE981, 0X2940, 0XEB01, 0X2BC0, 0X2A80, 0XEA41,
+    0XEE01, 0X2EC0, 0X2F80, 0XEF41, 0X2D00, 0XEDC1, 0XEC81, 0X2C40,
+    0XE401, 0X24C0, 0X2580, 0XE541, 0X2700, 0XE7C1, 0XE681, 0X2640,
+    0X2200, 0XE2C1, 0XE381, 0X2340, 0XE101, 0X21C0, 0X2080, 0XE041,
+    0XA001, 0X60C0, 0X6180, 0XA141, 0X6300, 0XA3C1, 0XA281, 0X6240,
+    0X6600, 0XA6C1, 0XA781, 0X6740, 0XA501, 0X65C0, 0X6480, 0XA441,
+    0X6C00, 0XACC1, 0XAD81, 0X6D40, 0XAF01, 0X6FC0, 0X6E80, 0XAE41,
+    0XAA01, 0X6AC0, 0X6B80, 0XAB41, 0X6900, 0XA9C1, 0XA881, 0X6840,
+    0X7800, 0XB8C1, 0XB981, 0X7940, 0XBB01, 0X7BC0, 0X7A80, 0XBA41,
+    0XBE01, 0X7EC0, 0X7F80, 0XBF41, 0X7D00, 0XBDC1, 0XBC81, 0X7C40,
+    0XB401, 0X74C0, 0X7580, 0XB541, 0X7700, 0XB7C1, 0XB681, 0X7640,
+    0X7200, 0XB2C1, 0XB381, 0X7340, 0XB101, 0X71C0, 0X7080, 0XB041,
+    0X5000, 0X90C1, 0X9181, 0X5140, 0X9301, 0X53C0, 0X5280, 0X9241,
+    0X9601, 0X56C0, 0X5780, 0X9741, 0X5500, 0X95C1, 0X9481, 0X5440,
+    0X9C01, 0X5CC0, 0X5D80, 0X9D41, 0X5F00, 0X9FC1, 0X9E81, 0X5E40,
+    0X5A00, 0X9AC1, 0X9B81, 0X5B40, 0X9901, 0X59C0, 0X5880, 0X9841,
+    0X8801, 0X48C0, 0X4980, 0X8941, 0X4B00, 0X8BC1, 0X8A81, 0X4A40,
+    0X4E00, 0X8EC1, 0X8F81, 0X4F40, 0X8D01, 0X4DC0, 0X4C80, 0X8C41,
+    0X4400, 0X84C1, 0X8581, 0X4540, 0X8701, 0X47C0, 0X4680, 0X8641,
+    0X8201, 0X42C0, 0X4380, 0X8341, 0X4100, 0X81C1, 0X8081, 0X4040
+  };
+
+unsigned int crc (byte* nData, unsigned int nLength){
+  byte nTemp;
+  unsigned int wCRCWord = 0xFFFF;
+
+   while (nLength--)
+   {
+      nTemp = *nData++ ^ wCRCWord;
+      wCRCWord >>= 8;
+      wCRCWord ^= TABLE[nTemp];
+   }
+   return wCRCWord;
+
+}

crc16_test/crc16.h

@@ -0,0 +1,8 @@
+#ifndef CRC16_h
+#define CRC16_h
+
+#include "Arduino.h"
+
+unsigned int crc (byte* nData, unsigned int nLength);
+
+#endif

crc16_test/crc16_test.ino

@@ -0,0 +1,19 @@
+# include "crc16.h"
+
+void setup() {
+  // put your setup code here, to run once:
+Serial.begin(9600);
+}
+
+void loop() {
+  byte array[] = {0x7e, 0x01, 0x01, 0x00, 0x00};
+  unsigned int crc16 = crc(array, 3);
+
+  byte high = highByte(crc16);
+  byte low = lowByte(crc16);
+  
+  Serial.print(crc16, HEX); Serial.print(" = ");
+  Serial.print(high, HEX); Serial.print(" ");
+  Serial.println(low, HEX);
+  delay(5000);
+}

data_types/.vscode/arduino.json

@@ -0,0 +1,7 @@
+{
+    "programmer": "AVRISP mkII",
+    "board": "arduino:avr:nano",
+    "configuration": "cpu=atmega328",
+    "port": "/dev/ttyUSB0",
+    "sketch": "test.ino"
+}

data_types/.vscode/c_cpp_properties.json

@@ -0,0 +1,20 @@
+{
+    "configurations": [
+        {
+            "name": "Linux",
+            "includePath": [
+                "/home/elex/.arduino15/packages/arduino/tools/**",
+                "/home/elex/.arduino15/packages/arduino/hardware/avr/1.6.19/**",
+                "/home/elex/.arduino15/packages/arduino/hardware/avr/1.6.19/cores/arduino"
+            ],
+            "forcedInclude": [
+                "/home/elex/.arduino15/packages/arduino/hardware/avr/1.6.19/cores/arduino/Arduino.h"
+            ],
+            "intelliSenseMode": "gcc-x64",
+            "compilerPath": "/usr/bin/gcc",
+            "cStandard": "c11",
+            "cppStandard": "c++17"
+        }
+    ],
+    "version": 4
+}

data_types/data_types.ino

@@ -0,0 +1,86 @@
+#include "datatypes.h"
+
+void setup() {
+  // start serial port at 9600 bps:
+  Serial.begin(9600);
+  
+}
+
+void loop() {
+  Int1 i1;
+  i1.value = 255;
+  print_test("Int1", toHexString(i1), toString(i1), sizeof(i1));
+  
+  UInt1 u1;
+  u1.value = 255;
+  print_test("UInt1", toHexString(u1), toString(u1), sizeof(u1));
+  
+
+  Int2 i2;
+  i2.value = -5536;
+  print_test("Int2", toHexString(i2), toString(i2), sizeof(i2));
+
+  UInt2 u2;
+  u2.value = 60000;
+  print_test("UInt2", toHexString(u2), toString(u2), sizeof(u2));
+
+
+  Int4 i4;
+  i4.value = 0xf0e0d0c0;
+  print_test("Int4", toHexString(i4), toString(i4), sizeof(i4));
+
+  UInt4 u4;
+  u4.value = 0xf0e0d0c0;
+  print_test("UInt4", toHexString(u4), toString(u4), sizeof(u4));
+
+
+  Int8 i8 = new_Int8(500);
+  print_test("Int8", toHexString(i8), toString(i8), sizeof(i8));
+  i8.value = 0xF0000000F0E0D0C0;
+  print_test("Int8", toHexString(i8), toString(i8), sizeof(i8));
+
+  UInt8 u8;
+  u8.value = 0xF0000000F0E0D0C0;
+  u8.value *= 300;
+  print_test("UInt8", toHexString(u8), toString(u8), sizeof(u8));
+
+
+  Float4 f4;
+  f4.value = 3.141592;
+  print_test("Float4", toHexString(f4), toString(f4), sizeof(f4));
+
+  
+  /*
+   * double -> float
+   */
+  byte ieee[8] = { // 3.141592
+    0x40, 0x09, 0x21, 0xfa, 0xfc, 0x8b, 0x00, 0x7a
+  };
+  f4 = conv_double_to_float(ieee);
+  print_test("Double -> Float4", toHexString(f4), toString(f4), sizeof(f4));
+
+  i2 = new_Int2(ieee, 2); // 0x21fa
+  print_test("Int2 from byte[]", toHexString(i2), toString(i2), sizeof(i2));
+
+  /*
+   * Operator
+   */
+  Int1 _i1;
+  _i1.value = -100;
+  i1 = i1+_i1;
+  print_test("Int1 + Int1", toHexString(i1), toString(i1), sizeof(i1));
+
+  i2 = 10+i1+100;
+  print_test("Int1 + int", toHexString(i2), toString(i2), sizeof(i2));
+
+  //Serial.println(crc(ieee, 2));
+  //Int8 as = new_Int8(500);
+  
+  delay(5000);
+}
+
+void print_test(String tag, String hexStr, String val, int size){
+  Serial.print(tag); Serial.print(" ("); Serial.print(size); Serial.print(")\n");
+  Serial.print("\t"); Serial.print(hexStr); Serial.print("\t"); Serial.print(val);
+  Serial.println("\n");
+}

data_types/datatypes.cpp

@@ -0,0 +1,509 @@
+#include "Arduino.h"
+#include "datatypes.h"
+
+#define INT8_CHAR_BUFF_SIZE 21
+#define DECIMAL_PLACE 6
+
+/*
+  바이트 배열을 역순으로
+*/
+void array_reverse(byte array[], unsigned int len, byte result[]){
+  for (int i=0; i<len;i++){
+    result[i] = array[len-1-i];
+  }
+}
+
+/*
+  캐릭터 배열을 역순으로.
+  len번째 요소에 널문자가 삽입됨.
+*/
+void char_array_reverse(char array[], unsigned int len, char result[]){  
+  for (int i=0; i<len;i++){
+    result[i] = array[len-1-i];
+  }
+  result[len]='\0';
+}
+
+/*
+   바이트 배열을 16진 문자열로.
+*/
+String array_to_string(byte array[], unsigned int len){
+  char result[len*2+1];
+  for (unsigned int i = 0; i < len; i++) {
+    byte nib1 = (array[i] >> 4) & 0x0F;
+    byte nib2 = (array[i] >> 0) & 0x0F;
+    result[i * 2 + 0] = nib1  < 0xA ? '0' + nib1  : 'A' + nib1  - 0xA;
+    result[i * 2 + 1] = nib2  < 0xA ? '0' + nib2  : 'A' + nib2  - 0xA;
+  }
+  result[len * 2] = '\0';
+  return String(result);
+}
+
+/*
+ * IEEE double procision을 single precision으로 변환.
+ * 
+ * https://github.com/RobTillaart/Arduino/blob/master/libraries/IEEE754tools/IEEE754tools.h
+ */
+Float4 conv_double_to_float(byte array[]){
+  Float4 fl;
+  Float8 dbl;
+  
+  for (int i=0; i<8; i++){
+      //dbl.bytes[i] = array[i];
+      dbl.bytes[i] = array[7-i];
+  }
+  
+  int exponent = dbl.p.exponent-1023 +127; // exponent adjust
+  // TODO check exponent overflow.
+  if (exponent >=0 || exponent <= 255) {
+        fl.p.sign = dbl.p.sign;
+        fl.p.exponent = exponent;  
+        fl.p.mentissa = dbl.p.mentissa;  // note this one clips the mantisse 
+        return fl;
+    }
+    return fl; // error
+}
+
+Float4 conv_double_to_float(Float8 val){
+  byte temp[8];
+  array_reverse(val.bytes, 8, temp);
+  return conv_double_to_float(temp);
+}
+
+// to String =====================================================================
+
+String toString(Int1 value){
+  return String((int)value.value);
+}
+
+String toString(UInt1 value){
+  return String(value.value);
+}
+
+String toString(Int2 value){
+  return String(value.value);
+}
+
+String toString(UInt2 value){
+  return String(value.value);
+}
+
+String toString(Int4 value){
+  return String(value.value);
+}
+
+String toString(UInt4 value){
+  return String(value.value);
+}
+
+String toString(Int8 value){
+  int m;
+  int i=0;
+  long long tmp = value.value;
+  char buff[INT8_CHAR_BUFF_SIZE], rev_buff[INT8_CHAR_BUFF_SIZE];
+  bool isMinus = tmp<0;
+  if (isMinus){
+    // 값이 음수인 경우, 
+    // 문자열에 부호를 추가하고, -1을 곱해서 양수로 만든 다음 나머지 작업을 한다.
+    // 부호 추가는 맨 뒤에.
+    tmp *=-1;
+  }
+  while (tmp/10>0) {
+    m = tmp%10;
+    buff[i]=(char)(m+0x30);
+    tmp /= 10;    
+    i++;
+  }
+  buff[i]=(char)(tmp+0x30);
+  if (isMinus){
+    i++;
+    buff[i] = '-'; // 부호를 추가
+  }
+  //buff[i+1] = '\0';
+  
+  //char arr[i+1];
+  char_array_reverse(buff, i+1, rev_buff);
+  rev_buff[i+1] = '\0';
+  return String(rev_buff);
+}
+
+String toString(UInt8 value){
+  int m;
+  int i=0;
+  unsigned long long tmp = value.value;
+  char buff[INT8_CHAR_BUFF_SIZE], rev_buff[INT8_CHAR_BUFF_SIZE];
+  while (tmp/10>0) {
+    m = tmp%10;
+    buff[i]=(char)(m+0x30);
+    tmp /= 10;    
+    i++;
+  }
+  buff[i]=(char)(tmp+0x30);
+  //buff[i+1] = '\0';
+
+  //char arr[i+1];
+  char_array_reverse(buff, i+1, rev_buff);
+  rev_buff[i+1] = '\0';
+  return String(rev_buff);
+}
+
+String toString(Float4 value){
+  return toString(value, DECIMAL_PLACE);
+}
+
+String toString(Float4 value, int decimalPlace){
+  return String(value.value, decimalPlace);
+}
+
+//String toString(Float8 value){
+//  return toString(value, DECIMAL_PLACE);
+//}
+
+//String toString(Float8 value, int decimalPlace){
+//  return String(value.value, decimalPlace);
+//}
+
+// to HEX String ===============================================================================
+
+String toHexString(Int1 value){
+  return array_to_string(value.bytes, 1);
+}
+
+String toHexString(UInt1 value){
+  return array_to_string(value.bytes, 1);
+}
+
+String toHexString(Int2 value){
+  byte rev_arr[2];
+  array_reverse(value.bytes, 2, rev_arr);
+  return array_to_string(rev_arr, 2);
+}
+
+String toHexString(UInt2 value){
+  byte rev_arr[2];
+  array_reverse(value.bytes, 2, rev_arr);
+  return array_to_string(rev_arr, 2);
+}
+
+String toHexString(Int4 value){
+  byte rev_arr[4];
+  array_reverse(value.bytes, 4, rev_arr);
+  return array_to_string(rev_arr, 4);
+}
+
+String toHexString(UInt4 value){
+  byte rev_arr[4];
+  array_reverse(value.bytes, 4, rev_arr);
+  return array_to_string(rev_arr, 4);
+}
+
+String toHexString(Int8 value){
+  byte rev_arr[8];
+  array_reverse(value.bytes, 8, rev_arr);
+  return array_to_string(rev_arr, 8);
+}
+
+String toHexString(UInt8 value){
+  byte rev_arr[8];
+  array_reverse(value.bytes, 8, rev_arr);
+  return array_to_string(rev_arr, 8);
+}
+
+String toHexString(Float4 value){
+  byte rev_arr[4];
+  array_reverse(value.bytes, 4, rev_arr);
+  return array_to_string(rev_arr, 4);
+}
+
+//String toHexString(Float8 value){
+//  byte rev_arr[8];
+//  array_reverse(value.bytes, 8, rev_arr);
+//  return array_to_string(rev_arr, 8);
+//}
+
+String toHexString(Int1 value, bool doNotRev){
+  return toHexString(value);
+}
+
+String toHexString(UInt1 value, bool doNotRev){
+  return toHexString(value);
+}
+
+String toHexString(Int2 value, bool doNotRev){
+  if (doNotRev){
+    return array_to_string(value.bytes, 2);
+  } else {
+    return toHexString(value);
+  }
+}
+
+String toHexString(UInt2 value, bool doNotRev){
+  if (doNotRev){
+    return array_to_string(value.bytes, 2);
+  } else {
+    return toHexString(value);
+  }
+}
+
+String toHexString(Int4 value, bool doNotRev){
+  if (doNotRev){
+    return array_to_string(value.bytes, 4);
+  } else {
+    return toHexString(value);
+  }
+}
+
+String toHexString(UInt4 value, bool doNotRev){
+  if (doNotRev){
+    return array_to_string(value.bytes, 4);
+  } else {
+    return toHexString(value);
+  }
+}
+
+String toHexString(Int8 value, bool doNotRev){
+  if (doNotRev){
+    return array_to_string(value.bytes, 8);
+  } else {
+    return toHexString(value);
+  }
+}
+
+String toHexString(UInt8 value, bool doNotRev){
+  if (doNotRev){
+    return array_to_string(value.bytes, 8);
+  } else {
+    return toHexString(value);
+  }
+}
+
+String toHexString(Float4 value, bool doNotRev){
+  if (doNotRev){
+    return array_to_string(value.bytes, 4);
+  } else {
+    return toHexString(value);
+  }
+}
+
+//String toHexString(Float8 value, bool doNotRev){
+//  if (doNotRev){
+//    return array_to_string(value.bytes, 8);
+//  } else {
+//    return toHexString(value);
+//  }
+//}
+
+// Constructors =========================================================================
+Int1 new_Int1(byte arr[]){
+  return new_Int1(arr, 0);
+}
+
+Int1 new_Int1(byte arr[], int startIdx){
+  Int1 v;
+  v.bytes[0] = arr[startIdx];
+  return v;
+}
+
+UInt1 new_UInt1(byte arr[]){
+  return new_UInt1(arr, 0);
+}
+
+UInt1 new_UInt1(byte arr[], int startIdx){
+  UInt1 v;
+  v.bytes[0] = arr[startIdx];
+  return v;
+}
+
+Int2 new_Int2(byte arr[]){
+  return new_Int2(arr, 0);
+}
+
+Int2 new_Int2(byte arr[], int startIdx){
+  Int2 v;
+  for (int i=0; i<2; i++) {
+    v.bytes[i] = arr[startIdx + 2-1-i];
+  }  
+  return v;
+}
+
+UInt2 new_UInt2(byte arr[]){
+  return new_UInt2(arr, 0);
+}
+
+UInt2 new_UInt2(byte arr[], int startIdx){
+  UInt2 v;
+  for (int i=0; i<2; i++) {
+    v.bytes[i] = arr[startIdx + 2-1-i];
+  }  
+  return v;
+}
+
+Int4 new_Int4(byte arr[]){
+  return new_Int4(arr, 0);
+}
+
+Int4 new_Int4(byte arr[], int startIdx){
+  Int4 v;
+  for (int i=0; i<4; i++) {
+    v.bytes[i] = arr[startIdx + 4-1-i];
+  }  
+  return v;
+}
+
+UInt4 new_UInt4(byte arr[]){
+  return new_UInt4(arr, 0);
+}
+
+UInt4 new_UInt4(byte arr[], int startIdx){
+  UInt4 v;
+  for (int i=0; i<4; i++) {
+    v.bytes[i] = arr[startIdx + 4-1-i];
+  }  
+  return v;
+}
+
+Int8 new_Int8(byte arr[]){
+  return new_Int8(arr, 0);
+}
+
+Int8 new_Int8(byte arr[], int startIdx){
+  Int8 v;
+  for (int i=0; i<8; i++) {
+    v.bytes[i] = arr[startIdx + 8-1-i];
+  }  
+  return v;
+}
+
+UInt8 new_UInt8(byte arr[]){
+  return new_UInt8(arr, 0);
+}
+
+UInt8 new_UInt8(byte arr[], int startIdx){
+  UInt8 v;
+  for (int i=0; i<8; i++) {
+    v.bytes[i] = arr[startIdx + 8-1-i];
+  }  
+  return v;
+}
+
+Float4 new_Float4(byte arr[]){
+  return new_Float4(arr, 0);
+}
+
+Float4 new_Float4(byte arr[], int startIdx){
+  Float4 v;
+  for (int i=0; i<4; i++) {
+    v.bytes[i] = arr[startIdx + 4-1-i];
+  }  
+  return v;
+}
+
+Float8 new_Float8(byte arr[]){
+  return new_Float8(arr, 0);
+}
+
+Float8 new_Float8(byte arr[], int startIdx){
+  Float8 v;
+  for (int i=0; i<8; i++) {
+    v.bytes[i] = arr[startIdx + 8-1-i];
+  }  
+  return v;
+}
+
+Int1 new_Int1(char val){
+  Int1 v;
+  v.value = val;
+  return v;
+}
+
+Int2 new_Int2(int val){
+  Int2 v;
+  v.value = val;
+  return v;
+}
+
+Int4 new_Int4(long val){
+  Int4 v;
+  v.value = val;
+  return v;
+}
+
+Int8 new_Int8(long long val){
+  Int8 v;
+  v.value = val;
+  return v;
+}
+
+UInt1 new_UInt1(byte val){
+  UInt1 v;
+  v.value = val;
+  return v;
+}
+
+UInt2 new_UInt2(unsigned int val){
+  UInt2 v;
+  v.value = val;
+  return v;
+}
+
+UInt4 new_UInt4(unsigned long val){
+  UInt4 v;
+  v.value = val;
+  return v;
+}
+
+UInt8 new_UInt8(unsigned long long val){
+  UInt8 v;
+  v.value = val;
+  return v;
+}
+
+Float4 new_Float4(float val){
+  Float4 v;
+  v.value = val;
+  return v;
+}
+
+//Float8 new_Float8(double val){
+//  Float8 v;
+//  v.value = val;
+//  return v;
+//}
+
+// 연산자 오버로딩 ========================================================================
+
+Int1 operator+(const Int1& a, const Int1& b){
+  Int1 val;
+  val.value = a.value + b.value;
+  return val;
+}
+
+Int2 operator+(const Int1& a, const int b){
+  Int2 val;
+  val.value = a.value + b;
+  return val;
+}
+
+Int2 operator+(const int a, const Int1& b){
+  Int2 val;
+  val.value = a + b.value;
+  return val;
+}
+
+Int2 operator+(const Int2& a, const Int2& b){
+  Int2 val;
+  val.value = a.value + b.value;
+  return val;
+}
+
+Int2 operator+(const Int2& a, const int b){
+  Int2 val;
+  val.value = a.value + b;
+  return val;
+}
+
+Int2 operator+(const int a, const Int2& b){
+  Int2 val;
+  val.value = a + b.value;
+  return val;
+}

data_types/datatypes.h

@@ -0,0 +1,266 @@
+#ifndef DataTypes_h
+#define DataTypes_h
+#include "Arduino.h"
+
+#define INT1_MAX = 0x7f;
+#define INT1_MIN = 0x80;
+#define UINT1_MAX = 0xff;
+#define UINT1_MIN = 0x00;
+
+#define INT2_MAX = 0x7fff;
+#define INT2_MIN = 0x8000;
+#define UINT2_MAX = 0xffff;
+#define UINT2_MIN = 0x0000;
+
+#define INT4_MAX = 0x7fffffffL;
+#define INT4_MIN = 0x80000000L;
+#define UINT4_MAX = 0xffffffffL;
+#define UINT4_MIN = 0x00000000L;
+
+#define INT8_MAX = 0x7fffffffffffffffLL;
+#define INT8_MIN = 0x8000000000000000LL;
+#define UINT8_MIN = 0xffffffffffffffffULL;
+#define UINT8_MIN = 0x0000000000000000ULL;
+
+/*
+ * IEEE754 float layout; 
+ * 
+ * Single Precision
+ * 부호 : 1 bit
+ * 지수(exponent) : 8 bit
+ * 가수(mentissa) : 23 bit
+ */
+struct IEEEsingle{
+    uint32_t mentissa:23; 
+    uint8_t exponent:8;
+    uint8_t sign:1;
+};
+
+// IEEE754 double layout; 
+struct IEEEdouble {
+    uint32_t filler:29; // it is only able to map 23 bits of the mantisse a filler is added for the remaining bits.
+    uint32_t mentissa:23; 
+    uint16_t exponent:11;
+    uint8_t sign:1;
+};
+
+/**
+ * 
+ * 자료형 ==============================================================================
+ * 
+ * 연산을 할 때에는 value를 사용.
+ * 바이트 배열을 처리할 때에는 bytes를 사용.
+ * bytes는 LowByte가 먼저이므로 주의.
+ * 
+ * TODO
+ * 클래스로 처리하고, 상속 구조로 바꾸면 더 편해질 것 같지만, C++ 쓸 줄 모름.
+ * 연산자 오버로딩의 경우에도 쉬운 방법이 있을 것 같지만, 능력 부족.
+ * 
+ */
+typedef union Int8 {
+  byte bytes[8];
+  long long value;
+} Int8;
+
+typedef union UInt8 {
+  byte bytes[8];
+  unsigned long long value;
+} UInt8;
+
+typedef union Int4 {
+  byte bytes[4];
+  long value;
+} Int4;
+
+typedef union UInt4 {
+  byte bytes[4];
+  unsigned long value;
+} UInt4;
+
+typedef union Int2 {
+  byte bytes[2];
+  int value;
+} Int2;
+
+typedef union UInt2 {
+  byte bytes[2];
+  unsigned int value;
+} UInt2;
+
+typedef union Int1 {
+  byte bytes[1];
+  char value;
+} Int1;
+
+typedef union UInt1 {
+  byte bytes[1];
+  byte value;
+} UInt1;
+
+
+typedef union Float4 {
+  byte bytes[4];
+  float value; // 4 bytes
+  IEEEsingle p;
+} Float4;
+
+typedef union Float8 { // double->float 변환용으로만 사용한다.
+  byte bytes[8];
+  double value; // 4 bytes
+  IEEEdouble p;
+} Float8;
+
+/**
+ * 
+ * Constructors ==========================================================
+ * 
+ */
+
+Int1 new_Int1(char val);
+Int2 new_Int2(int val);
+Int4 new_Int4(long val);
+Int8 new_Int8(long long val);
+
+UInt1 new_UInt1(byte val);
+UInt2 new_UInt2(unsigned int val);
+UInt4 new_UInt4(unsigned long val);
+UInt8 new_UInt8(unsigned long long val);
+
+Float4 new_Float4(float val);
+//Float8 new_Float8(double val);
+
+Int1 new_Int1(byte arr[]);
+Int2 new_Int2(byte arr[]);
+Int4 new_Int4(byte arr[]);
+Int8 new_Int8(byte arr[]);
+
+/*
+ * arr : 맨 왼쪽부터 순서대로라고 가정한다.
+ * startIdx : arr 배열에서 값을 읽어올 시작 위치 인덱스
+ */
+Int1 new_Int1(byte arr[], int startIdx);
+Int2 new_Int2(byte arr[], int startIdx);
+Int4 new_Int4(byte arr[], int startIdx);
+Int8 new_Int8(byte arr[], int startIdx);
+
+UInt1 new_UInt1(byte arr[]);
+UInt2 new_UInt2(byte arr[]);
+UInt4 new_UInt4(byte arr[]);
+UInt8 new_UInt8(byte arr[]);
+
+UInt1 new_UInt1(byte arr[], int startIdx);
+UInt2 new_UInt2(byte arr[], int startIdx);
+UInt4 new_UInt4(byte arr[], int startIdx);
+UInt8 new_UInt8(byte arr[], int startIdx);
+
+Float4 new_Float4(byte arr[]);
+Float8 new_Float8(byte arr[]);
+
+Float4 new_Float4(byte arr[], int startIdx);
+Float8 new_Float8(byte arr[], int startIdx);
+
+/*
+ * IEEE754 배정도 부동소수를 단정도 부동소수로 변환.
+ * 
+ * array : IEEE 배정도 부동소수 (8바이트). 
+ * 부호비트가 맨 왼쪽에 있다고 본다. 아니라면, 뒤집어서 입력할 것.
+ */
+Float4 conv_double_to_float(byte array[]);
+Float4 conv_double_to_float(Float8 val);
+
+/**
+ * 
+ * Operators ========================================================================
+ * 
+ * 경우의 수가 너무 많으므로 필요할 때마다 추가해야할 듯.
+ * template 같은 걸 쓰면 될 것 같은데, 어떻게 쓰는건지 모르겠음.
+ * 또는, .value를 사용해서 연산하는데 편할 듯.
+ */
+
+Int1 operator+(const Int1& a, const Int1& b);
+Int2 operator+(const Int1& a, const int b);
+Int2 operator+(const int a, const Int1& b);
+Int2 operator+(const Int2& a, const Int2& b);
+Int2 operator+(const Int2& a, const int b);
+Int2 operator+(const int a, const Int2& b);
+
+/**
+ * 
+ * To HEX String ======================================================
+ * 
+ */
+
+// HighByte가 먼저 출력됨.
+String toHexString(Int1 value);
+String toHexString(Int2 value);
+String toHexString(Int4 value);
+String toHexString(Int8 value);
+
+String toHexString(UInt1 value);
+String toHexString(UInt2 value);
+String toHexString(UInt4 value);
+String toHexString(UInt8 value);
+
+String toHexString(Float4 value);
+//String toHexString(Float8 value);
+
+// doNotRev :  true이면 LowByte가 먼저 출력됨.
+String toHexString(Int1 value, bool doNotRev);
+String toHexString(Int2 value, bool doNotRev);
+String toHexString(Int4 value, bool doNotRev);
+String toHexString(Int8 value, bool doNotRev);
+
+String toHexString(UInt1 value, bool doNotRev);
+String toHexString(UInt2 value, bool doNotRev);
+String toHexString(UInt4 value, bool doNotRev);
+String toHexString(UInt8 value, bool doNotRev);
+
+String toHexString(Float4 value, bool doNotRev);
+//String toHexString(Float8 value, bool doNotRev);
+
+/**
+ * 
+ * To String ======================================================
+ * 
+ */
+
+String toString(Int1 value);
+String toString(Int2 value);
+String toString(Int4 value);
+String toString(Int8 value);
+
+String toString(UInt1 value);
+String toString(UInt2 value);
+String toString(UInt4 value);
+String toString(UInt8 value);
+
+/*
+   decimalPlace : 소수점 이하 자릿수
+ */
+String toString(Float4 value, int decimalPlace);
+String toString(Float4 value);
+//String toString(Float8 value, int decimalPlace);
+//String toString(Float8 value);
+
+/**
+ * 
+ * Utilities ======================================================
+ * 
+ */
+
+/*
+  바이트 배열을 16진수 문자열로.
+  array : 원본 배열
+  len : 배열 길이
+*/
+String array_to_string(byte array[], unsigned int len);
+
+/*
+  바이트 배열의 순서를 뒤집기.
+  array : 원본 배열
+  len : 배열 길이
+  result : 뒤집힌 배열이 저장될 새로운 배열
+*/
+void array_reverse(byte array[], unsigned int len, byte result[]);
+
+#endif