Using arrays for BCD conversion in C

Question

I'm working on a project where I need to convert some long variables into BCD.

I already have some code that works but I feel that it can be improved...

void main(void){
    unsigned long input = 0;
    unsigned long convert = 0;
    float convert2 = 0;
    char buffer[200];
    unsigned char Ones, Tens, Hundreds, Thousands, TenThousands, HundredThousands;

    printf("Input:   ");
    scanf("%d", &input);

    convert = input*12;
    convert2 = input * 0.0001224896;

    BCD(convert, &Ones, &Tens, &Hundreds, &Thousands, &TenThousands, &HundredThousands);
    sprintf(buffer, "%d%d%dKG", HundredThousands, TenThousands, Thousands);

    printf("\n\nInputted: %d", input);
    printf("\nADC Conversion: %d", convert);
    printf("\nBCD Conversion: %s", buffer);
    printf("\nFloat Conversion: %f", convert2);

    getchar();
    getchar();
}

void BCD (unsigned long Pass, unsigned char *Ones, unsigned char *Tens, unsigned char *Hundreds, unsigned char *Thousands, unsigned char *TenThousands, unsigned char *HundredThousands){

    unsigned char temp1, temp2, temp3, temp4, temp5, temp6;
    unsigned int count = 0;

    *Ones = 0;
    *Tens = 0;
    *Hundreds = 0;
    *Thousands = 0;
    *TenThousands = 0;
    *HundredThousands = 0;
    temp1 = 0;
    temp2 = 0;
    temp3 = 0;
    temp4 = 0;
    temp5 = 0;
    temp6 = 0;

    for(count = 0; count <= 31; count++){
    if (*Ones >= 5){                                                       
        *Ones = (*Ones + 3)&0x0F;                                           
    }                                                                    
    if (*Tens >= 5){
        *Tens = (*Tens + 3)&0x0F;
    }
    if (*Hundreds >= 5){
        *Hundreds = (*Hundreds + 3)&0x0F;
    }
    if (*Thousands >= 5){
        *Thousands = (*Thousands + 3)&0x0F;
    }
    if (*TenThousands >= 5){
        *TenThousands = (*TenThousands + 3)&0x0F;
    }
    if (*HundredThousands >= 5){
        *HundredThousands = (*HundredThousands + 3)&0x0F;
    }

    temp1 = (Pass & 2147483648) >> 31;                                          
    temp2 = (*Ones & 8) >> 3;                                               
    temp3 = (*Tens & 8) >> 3;
    temp4 = (*Hundreds & 8) >> 3;
    temp5 = (*Thousands & 8) >> 3;
    temp6 = (*TenThousands & 8) >> 3;

    Pass = Pass << 1;
    *Ones = ((*Ones << 1) + temp1) & 15;                                   
    *Tens = ((*Tens << 1) + temp2) & 15;                                    
    *Hundreds = ((*Hundreds << 1) + temp3) & 15;
    *Thousands = ((*Thousands << 1) + temp4) & 15;
    *TenThousands = ((*TenThousands << 1) + temp5) & 15;
    *HundredThousands = ((*HundredThousands << 1) + temp6) & 15;


    printf("\n\nLoop: %d\nOnes:             %d\n", count, *Ones);
    printf("Tens:             %d\n", *Tens);
    printf("Hundreds:         %d\n", *Hundreds);
    printf("Thousands:        %d\n", *Thousands);
    printf("TenThousands:     %d\n", *TenThousands);
    printf("HundredThousands: %d\n",*HundredThousands);
    }
}

The problem I have with this is that it seems messy and inefficient. I was think that instead of using multiple variable for each BCD unit (Ones, Tens, etc), I could use an arrays to carry out the same process. I have implemented this in code but I'm running into a few problems. The code only seems to display "Ones" equivalent element. I've stepped through the code as well and found that the other elements are not being populated during the conversion process. Any guidance on what is going on?

Array implementation:

void main(void){
    unsigned long input = 0;
    unsigned long convert = 0;
    char buffer[200];
    unsigned char BCD_Units[6];
    unsigned char temp[6];
    unsigned int count = 0;
    unsigned int count1 = 0;
    unsigned char buff_store = 0;
    unsigned char buff_store2 = 0;

    printf("Input:   ");
    scanf("%d", &input);

    convert = input;

    memset(temp, 0, sizeof(temp));
    memset(BCD_Units, 0, sizeof(BCD_Units));

    for(count = 0; count <= 31; count++){
        for (count1 = 0; count1 < 6; count1++){
            if (BCD_Units[count1] >= 5){
                buff_store = BCD_Units[count1];

                buff_store = ((buff_store + 3) & 15);

                BCD_Units[count1] = buff_store;
            }
        }

        temp[0] = (convert & 2147483648) >> 31;
        for (count1 = 0; count1 < 5; count1++){
            buff_store = BCD_Units[count1];

            temp[(count+1)] = (buff_store & 8) >> 3;
        }

        convert = convert << 1;
        for(count1 = 0; count1 < 6; count1++){
            buff_store = BCD_Units[count1];
            buff_store2 = temp[count1];

            buff_store = ((buff_store << 1) + buff_store2) & 15;

            BCD_Units[count1] = buff_store;
            temp[count1] = buff_store2;
        }

        printf("\n\nLoop: %d\nOnes:             %d\n", count, BCD_Units[0]);
        printf("Tens:             %d\n", BCD_Units[1]);
        printf("Hundreds:         %d\n", BCD_Units[2]);
        printf("Thousands:        %d\n", BCD_Units[3]);
        printf("TenThousands:     %d\n", BCD_Units[4]);
        printf("HundredThousands: %d\n", BCD_Units[5]);
    }

    sprintf(buffer, "%d%d%dKG", BCD_Units[5], BCD_Units[4], BCD_Units[3]);
    printf("\n\nInputted: %d", input);
    printf("\nBCD Conversion: %s", buffer);

    getchar();
    getchar();
}

PS. I'm just playing around, at the moment, with ideas. I plan to compartmentalise the code into functions at a later date.

Answer 1

this code seems enormously complicated. YOu just need to do the following

make a buffer
loop till n = 0
 get n % 10 (get digit)
 or digit into left or right nibble of curretn buffer byte (need a toggle for left or right)
 increment buffer pointer if filled left nibble
 n = n / 10

try this Convert integer from (pure) binary to BCD