program memory usage need help

without

sprintf(lcddata,"C.TEMP:%.02fC" ,dert);

Memory Summary:
Program space used 45Eh ( 1118) of 1000h words ( 27.3%)
Data space used 53h ( 83) of 170h bytes ( 22.6%)
EEPROM space used 0h ( 0) of 100h bytes ( 0.0%)
Configuration bits used 0h ( 0) of 2h words ( 0.0%)
ID Location space used 0h ( 0) of 4h bytes ( 0.0%)

Loaded E:\pic_projeler\1 wire bus ds18b20\1wiresergu\1wire.cof.

********** Build successful! **********



with

sprintf(lcddata,"C.TEMP:%.02fC" ,dert);

Memory Summary:
Program space used F23h ( 3875) of 1000h words ( 94.6%)
Data space used 97h ( 151) of 170h bytes ( 41.0%)
EEPROM space used 0h ( 0) of 100h bytes ( 0.0%)
Configuration bits used 0h ( 0) of 2h words ( 0.0%)
ID Location space used 0h ( 0) of 4h bytes ( 0.0%)

Loaded E:\pic_projeler\1 wire bus ds18b20\1wiresergu\1wire.cof.

********** Build successful! **********

compiler is HI-TECH C Compiler for PIC10/12/16 MCUs (PRO Mode) V9.83

these are the output without and with sprintf. why program space usage are changing too much. (from %27.3 %to 94.6)

That's ok. Never use this function again.

Easyrider83 said:

That's ok. Never use this function again.

Click to expand...

by that is ok you mean it is normal? if so why so much change?

if not use that function how can i put a float value into a string ?

what is the memory size you have allocated to ' lcddata ' ?

Raady Here said:

what is the memory size you have allocated to ' lcddata ' ?

Click to expand...

unsigned char lcddata[20];
float dert=0;

The reason is 'sprintf' and it's associated functions are among the most memory hungry in the C library. It has lots of features you may not need to use so in a device with limited memory it is often better to use your own routines which can be optimized for only the features you use.

Brian.

betwixt said:

it is often better to use your own routines which can be optimized for only the features you use

Click to expand...

Another possibility would be test different compiler optimization levels to check if can reach some reduction of memory usage. In order to allow the program keep some level of portability to other uC cores, it is somewhat advisable to use the standard C libraries instead of direct access to special function registers.

andre_teprom said:

Another possibility would be test different compiler optimization levels to check if can reach some reduction of memory usage. In order to allow the program keep some level of portability to other uC cores, it is somewhat advisable to use the standard C libraries instead of direct access to special function registers.

Click to expand...

" it is somewhat advisable to use the standard C libraries instead of direct access to special function registers. "

what you mean by standart libraries ? what are they and where i can find them ?
what does accesing to special function registers mean ? what are they?

i know maybe these are basic question but it will help me if you can just give me one example for each.

- - - Updated - - -

Easyrider83 said:

Code:

void FloatToString (float Value, char * String, char Accuracy)
{
	signed long k = 1;
	signed long tmp; 
	char Len;
	while (Accuracy--) k = k * 10;
	if (Value<0)	tmp = ((signed long)Value)*k - (float)(Value*k); 
		else tmp = (float)(Value*k) - ((signed long)Value)*k;
	sLongToStr((signed long)Value, String);
	Len = StringLen(String);
	String[Len++]='.';
	uLongToStr(tmp, String+Len);
}

Code:

signed long uLongTosLong (unsigned long Value)
{
	signed long Result;
	if ((Value)&(1<<30)) Result = - (0xFFFFFFFF - Value);
	else Result = Value;
	return Result;
}

Code:

void sLongToStr (signed long Value, char * String)
{
	unsigned long tmp;
	if (Value<0) 
	{
		Value=-Value;
		tmp=Value;
		*String++='-';
		uLongToStr(tmp, String+1);
	}
	else
	{
		tmp=Value;
		uLongToStr(tmp, String);
	}
}

Click to expand...

firstly thankx for helping.

what is the accuracy parameter in real you use in FloatToString function ? accuracy is .03 in 2.03 ? decimal accuracy i mean ?
also i didnt see the function uLongToStr u use in other functions? is it a function known by compiler or ?

2.03 accuracy 2
1.1 accuracy 1
3.1415 accuracy 4
just amount of digits after the dot

Easyrider83 said:

2.03 accuracy 2
1.1 accuracy 1
3.1415 accuracy 4
just amount of digits after the dot

Code:

void uLongToStr (unsigned long Value, char * String)
{
  char zero=0;
  char tmp=0;
  unsigned long cnt=1000000000;
  while (cnt!=1)
  {
    while (Value>=cnt)
    {
      Value-=cnt;
      tmp++;
    }
    if (tmp) zero=1;
    if (zero) * String++ = tmp+48;
    tmp=0;
    cnt/=10;
  }
  * String = Value+48;
}

Click to expand...

it is working ty.
but,
it is not giving correct values between zero and minus one.

Thanks
Damn, I will check this. Possible, some math optimization problems.

Easyrider83 said:

Thanks
Damn, I will check this. Possible, some math optimization problems.

Click to expand...

also one more thing if you will check.

2.3456 with accuracy 4. when i use accuracy 3 then it is 2.345. it should be rolled to 2.346

3.00625; with 4 accuracy it is writing 3.62

Try this:

Easyrider83 said:

Try this:

Code:

void FloatToString (float Value, char * String, char Accuracy)
{
        signed long k = 1;
        signed long tmp;
        char Len, Len2, i=0;
        char AftDot[6];
        for (tmp = Accuracy; tmp; tmp--)  k *= 10;
        tmp = MOD(((signed long)Value)*k - Value*k);
        sLongToStr((int)Value, String);
        Len = StringLen(String);
        String[Len++]='.';
        sLongToStr(tmp, AftDot);
        Len2 =  StringLen(AftDot);

        while (Accuracy--)
        {
              if (Accuracy>=Len2) String[Len++] = '0';
              else String[Len++] = AftDot[i++];
        }
}

Code:

unsigned char StringLen (char * String)
{
        char cnt=0;
        while (* String++) cnt++;
        return cnt;
}

Code:

void sLongToStr (signed long Value, char * String)
{
        unsigned long tmp;
        if (Value<0) 
        {
                Value=-Value;
                tmp=Value;
                *String='-';
                uLongToStr(tmp, String+1);
        }
        else
        {
                tmp=Value;
                uLongToStr(tmp, String);
        }
}

Code:

void uLongToStr (unsigned long Value, char * String)
{
  char zero=0;
  char tmp=0;
  unsigned long cnt=1000000000;
  while (cnt!=1)
  {
    while (Value>=cnt)
    {
      Value-=cnt;
      tmp++;
    }
    if (tmp) zero=1;
    if (zero) * String++ = tmp+48;
    tmp=0;
    cnt/=10;
  }
  * String = Value+48;
}

Click to expand...

tmp = MOD(((signed long)Value)*k - Value*k); What is MOD?

Sorry, it just a module of value

Easyrider83 said:

Sorry, it just a module of value

Code:

unsigned long MOD (signed long Value)
{
        if (Value>0) return Value;
        else return -Value;
}

Click to expand...

tmp = MOD(((signed long)Value)*k - Value*k); What does the signed long before value does in this expression ?

it's just a type conversion. Value is a float, and it should be converted to char/int/long.

type conversion ?

let say value is 3.023452 and let say accuracy is 2. (signed long)Value)*k what we are getting ? 302 or ?
what this expression giveus?
(((signed long)Value)*k - Value*k)