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How can we manage a 64 bits integer number to convert it to ASCCII value for LCD display. Does SPRINTF work with 'double' data type reguards.
I doubt that anyone would want to read a 20-digit number (which corresponds to 64 bits) from a display. What I would suggest is to convert such number to something shorter (say, 32 bits) and then to display it. This would be an approximation, but people do it all the time. Regards, Mike
The ISO 11784 norm for animal identification code Idf number on 38 bits so we need a data type greater than unsigned long. I ask for 64 bits because a 38 bits data type may not exist!
Sorry, I should have guessed it would be something like this. It's no easy task - to convert a 38-bit number into decimal. Octal and hexadecimal numbers suit much better because conversion routines for them are quite straightforward. I'm afraid in case of decimals one would have to re-invent integer arithmetics for 38-bit numbers. good luck mike
Does SPRINTF work with 'double' data type Please read the manual! (jst clik on SPRINTF in your code & press F1!) No, because C51 does not have a 'double' data type! But do you really need it in an arithmetic data type? ie, do you actually need to do any maths with it? If it's just an ID number, presumably not; so why not just store it as a string? As you're comtemplating sprintf, I assume you're not tight on space? But if you are, could you store it in a BCD format; 2 decimal digits to each byte?
How about this method. You will need to define an array of 38 elements. Each element is an unsigned long. Each element n is initialised to 2 to the power of n+1 and uses BCD representation.
= { 0x00000001, 0x00000002, 0x00000004, 0x00000008, 0x00000016, 0x00000032....etc. }
Out of curiosity I came up with the following code to convert n binary digits to m decimal digits. This is the essence of a solution which may be readily adapted to your specific needs. The code includes a number of test examples. It compiles to reasonably efficient code, although making use of memory specific pointers would be much better than generic pointers.
#define BINARY_DIGITS 38 #define DECIMAL_DIGITS 12 // 1 2 3 // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 xdata unsigned char big_binary_00[ BINARY_DIGITS ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 }; xdata unsigned char big_binary_01[ BINARY_DIGITS ] = { 1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 }; xdata unsigned char big_binary_10[ BINARY_DIGITS ] = { 0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 }; xdata unsigned char big_binary_16[ BINARY_DIGITS ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 }; xdata unsigned char big_binary_38[ BINARY_DIGITS ] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1 }; xdata unsigned char big_binary_xx[ BINARY_DIGITS ] = { 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 }; xdata unsigned char big_decimal[ DECIMAL_DIGITS ]; void conversion( unsigned char *binary, unsigned char *decimal ) { unsigned char loop; unsigned char outer_loop; unsigned char *d; unsigned char *t; unsigned char carry = 0; unsigned char temp[ DECIMAL_DIGITS ]; // // Initialise Data // loop = DECIMAL_DIGITS; d = decimal; t = &temp[ 0 ]; do { *t = 0; t++; *d = 0; d++; }while( --loop != 0 ); temp[ 0 ] = 1; outer_loop = BINARY_DIGITS; do { if( *binary != 0 ) { // // Set d to d plus t // loop = DECIMAL_DIGITS; carry = 0; t = &temp[ 0 ]; d = &decimal[ 0 ]; do { *d = (*d + *t) + carry; if( *d < 10 ) { carry = 0; } else { *d = *d - 10; carry = 1; } d++; t++; }while( --loop != 0 ); } // // Double the BCD value in t // loop = DECIMAL_DIGITS; carry = 0; t = &temp[ 0 ]; do { *t = (*t * 2) + carry; if( *t < 10 ) { carry = 0; } else { *t = *t - 10; carry = 1; } t++; }while( --loop != 0 ); binary++; }while( --outer_loop != 0 ); } main( void ) { conversion( &big_binary_00, &big_decimal ); conversion( &big_binary_01, &big_decimal ); conversion( &big_binary_10, &big_decimal ); conversion( &big_binary_16, &big_decimal ); conversion( &big_binary_38, &big_decimal ); conversion( &big_binary_xx, &big_decimal ); conversion( &big_binary_xx, &big_decimal ); }