Sam Grove / atoh

Utility to convert hex formatted ascii to binary system types.

Dependents:   Nucleo_read_hyperterminale

Helper for parsing ASCII communications

Example

#include "mbed.h"
#include "atoh.h"

int main()
{
    uint64_t result = atoh <uint64_t> ("0123456789abcdef" );
    uint32_t lo = result & 0x00000000ffffffff;
    uint32_t hi = (result >> 32);
    printf( "0x%08X%08X\n", hi, lo );
    printf( "0x%08X\n", atoh <uint32_t> ( "12345678" ) );
    printf( "0x%04X\n", atoh <uint16_t> ( "1234" ) );
    printf( "0x%02X\n", atoh <uint8_t> ( "12" ) );
}

atoh.cpp@0:fbac423fa3d4, 2013-03-07 (annotated)

Committer:
sam_grove
Date:
Thu Mar 07 21:38:29 2013 +0000
Revision:
0:fbac423fa3d4
Cleaned up documentation and updated example

Who changed what in which revision?

UserRevisionLine numberNew contents of line
sam_grove 0:fbac423fa3d4 1 /**
sam_grove 0:fbac423fa3d4 2 * @file atoh.cpp
sam_grove 0:fbac423fa3d4 3 * @brief Convert an ASCII hex string to hexadecimal - seems like the
sam_grove 0:fbac423fa3d4 4 * std library should include this... maybe it does. Just couldn't find it
sam_grove 0:fbac423fa3d4 5 * @author sam grove
sam_grove 0:fbac423fa3d4 6 * @version 1.0
sam_grove 0:fbac423fa3d4 7 *
sam_grove 0:fbac423fa3d4 8 * Copyright (c) 2013
sam_grove 0:fbac423fa3d4 9 *
sam_grove 0:fbac423fa3d4 10 * Licensed under the Apache License, Version 2.0 (the "License");
sam_grove 0:fbac423fa3d4 11 * you may not use this file except in compliance with the License.
sam_grove 0:fbac423fa3d4 12 * You may obtain a copy of the License at
sam_grove 0:fbac423fa3d4 13 *
sam_grove 0:fbac423fa3d4 14 * http://www.apache.org/licenses/LICENSE-2.0
sam_grove 0:fbac423fa3d4 15 *
sam_grove 0:fbac423fa3d4 16 * Unless required by applicable law or agreed to in writing, software
sam_grove 0:fbac423fa3d4 17 * distributed under the License is distributed on an "AS IS" BASIS,
sam_grove 0:fbac423fa3d4 18 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
sam_grove 0:fbac423fa3d4 19 * See the License for the specific language governing permissions and
sam_grove 0:fbac423fa3d4 20 * limitations under the License.
sam_grove 0:fbac423fa3d4 21 */
sam_grove 0:fbac423fa3d4 22
sam_grove 0:fbac423fa3d4 23 #include "atoh.h"
sam_grove 0:fbac423fa3d4 24
sam_grove 0:fbac423fa3d4 25 template<typename T>
sam_grove 0:fbac423fa3d4 26 T atoh( char const *string )
sam_grove 0:fbac423fa3d4 27 {
sam_grove 0:fbac423fa3d4 28 T value = 0;
sam_grove 0:fbac423fa3d4 29 char ch = 0;
sam_grove 0:fbac423fa3d4 30 uint8_t digit = 0, bail = sizeof(T) << 1;
sam_grove 0:fbac423fa3d4 31
sam_grove 0:fbac423fa3d4 32 // loop until the string has ended
sam_grove 0:fbac423fa3d4 33 while ( ( ch = *(string++) ) != 0 )
sam_grove 0:fbac423fa3d4 34 {
sam_grove 0:fbac423fa3d4 35 // service digits 0 - 9
sam_grove 0:fbac423fa3d4 36 if ( ( ch >= '0' ) && ( ch <= '9' ) )
sam_grove 0:fbac423fa3d4 37 {
sam_grove 0:fbac423fa3d4 38 digit = ch - '0';
sam_grove 0:fbac423fa3d4 39 }
sam_grove 0:fbac423fa3d4 40 // and then lowercase a - f
sam_grove 0:fbac423fa3d4 41 else if ( ( ch >= 'a' ) && ( ch <= 'f' ) )
sam_grove 0:fbac423fa3d4 42 {
sam_grove 0:fbac423fa3d4 43 digit = ch - 'a' + 10;
sam_grove 0:fbac423fa3d4 44 }
sam_grove 0:fbac423fa3d4 45 // and uppercase A - F
sam_grove 0:fbac423fa3d4 46 else if ( ( ch >= 'A' ) && ( ch <= 'F' ) )
sam_grove 0:fbac423fa3d4 47 {
sam_grove 0:fbac423fa3d4 48 digit = ch - 'A' + 10;
sam_grove 0:fbac423fa3d4 49 }
sam_grove 0:fbac423fa3d4 50 // stopping where we are if an inapproprate value is found
sam_grove 0:fbac423fa3d4 51 else
sam_grove 0:fbac423fa3d4 52 {
sam_grove 0:fbac423fa3d4 53 break;
sam_grove 0:fbac423fa3d4 54 }
sam_grove 0:fbac423fa3d4 55 // if the return is 8, 16, or 32 bits - only parse that amount
sam_grove 0:fbac423fa3d4 56 if ( bail-- == 0 )
sam_grove 0:fbac423fa3d4 57 {
sam_grove 0:fbac423fa3d4 58 break;
sam_grove 0:fbac423fa3d4 59 }
sam_grove 0:fbac423fa3d4 60 // and build the value now, preparing for the next pass
sam_grove 0:fbac423fa3d4 61 value = (value << 4) + digit;
sam_grove 0:fbac423fa3d4 62 }
sam_grove 0:fbac423fa3d4 63
sam_grove 0:fbac423fa3d4 64 return value;
sam_grove 0:fbac423fa3d4 65 }
sam_grove 0:fbac423fa3d4 66
sam_grove 0:fbac423fa3d4 67 template uint8_t atoh <uint8_t> (const char* string );
sam_grove 0:fbac423fa3d4 68 template uint16_t atoh <uint16_t>(const char* string );
sam_grove 0:fbac423fa3d4 69 template uint32_t atoh <uint32_t>(const char* string );
sam_grove 0:fbac423fa3d4 70 template uint64_t atoh <uint64_t>(const char* string );
sam_grove 0:fbac423fa3d4 71