BCD to ASCII conversion

[kumaru_san]

I want to convert from BCD to ASCII ?

How to write a program for that?

Code snippet or logic would be grateful!

[Ajay Vijay]

Where is your BCD data? I mean what is the format of this source?

[dude_1967]

kumaru_san,

Simply convert each individual BCD byte to a ASCII character by adding 0x30 to the BCD byte.

Take a look at the code below in C++.

Sincerely, Chris.

#include <iostream>
#include <sstream>
#include <string>

typedef unsigned char UINT8;

bool BCD_to_ASCII(const UINT8* bcd, const int length, ::std::string& str_ascii)
{
  if(length)
  {
    ::std::stringstream ss;

    for(int i = 0; i < length; i++)
    {
      ss << static_cast<char>(bcd[i] + 0x30);
    }

    ss << ::std::endl;

    ss >> str_ascii;

    return true;
  }
  else
  {
    return false;
  }
}

int main(int argc, char* argv[])
{
  UINT8 bcd[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
  ::std::string str;

  BCD_to_ASCII(bcd, sizeof(bcd)/ sizeof(bcd[0]), str);

  ::std::cout << str << ::std::endl;

  return 0;
}

[kumaru_san]

hello again..

for example if i input as "47" i need the ASCII value of 47.

4 - 0100

7- 0111

so i write 47 in BCD as

4 7
0100 0111


public static string BCDTOASCII(string sourcestring)
{

// convert the sourcestring (BCD string) to ASCII string
// and return the value
// here the BCD string 47 has to converted into ASCII string

}


How to do that?
Could u help me out ?

The above function is available in Java libraray.
I want to write same one in C++.

[kumaru_san]

hey chris,

i read ur code snippet ..
thanks lot. i will try it out now.

[kumaru_san]

but why do we add 0x30 ?

[Caronte]

Because the decimal value for the '0' Ascii is 0x30...

That is:

'4' = 4 + '0' = 4 + 0x30.

However if you have a decimal value that ranges from 0 to 0xff you have first splitt it into three decimal digits (that goes from 0 to 9) or two hexadecimal digits (that goes from 0 to f)

[kumaru_san]

thanks lot.
I understood now.

[VipulPathak]

Hey dude_1967,

I was trying to interpret BCD byte array. I seen your solution and wow it worked.

3 cheers to your solution :-)

*(Vipul)() ;

[dude_1967]

Hi,

I just had a look at this old thread.

It is not necessary to modify anything.

However I might code this functionality slightly differently these days. I would probably try to compact the code a bit through a sensible use of the standard library function std::transform as shown below. The resulting code is more compact and probably better in this alternate form.

Sincerely, Chris.

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>

typedef unsigned char UINT8;

namespace
{
  static char BCD_to_ASCII(const UINT8& u)
  {
    return static_cast<char>(u + static_cast<UINT8>(0x30u));
  }
}

int main(int argc, char* argv[])
{
  // Declare the data which should be converted BCD.
  static const UINT8 bcd_data[] = { 1, 2, 3, 4, 5, 6, 7, 8 };

  // Put these data into a standard vector container.
  static const std::vector<UINT8> bcd(bcd_data, bcd_data + (sizeof(bcd_data) / sizeof(bcd_data[0])));

  // Declare an output string for the conversion and be sure that it is created with
  // enough storage space.
  std::string str(bcd.size(), static_cast<char>('\0'));

  // Use the standard function std::transform in combination with a unary function for
  // the conversion.
  std::transform(bcd.begin(), bcd.end(), str.begin(), ::BCD_to_ASCII);

  std::cout << str << std::endl;
}