How to display Real number ??

[ee_cchac]

dear all,

i now facing a simple problem.....when i going to calculate the means of a set of value. i was able to find the means...but it is an integer....i try to force it to float...double....but all result in error value.
my h/w as follow:

AT86RF211 development kit. with MCUs AT90LS8535

code is as follow:

unsigned int a;
float intx;

for ( int i =0; i <9 ; i++)
a= a+a;
x= x/a;

x sow only an integer....but i want real number...


i wonder the reason is due to the LCD display....what should i do ??? help....please...

 

[vdaniel]

It is not clear.


unsigned int a;
float intx;

for ( int i =0; i <9 ; i++)
a= a+a;
x= x/a;

Where is the x declaration?
If in the second line, then should be just "float x".

Best regards,
Varuzhan

 

[ee_cchac]

code as follow :
//////////////////////////////////////////
unsigned int a;
float x;

for ( int i =0; i <9 ; i++)
a= a+a;
x= x/a;
///////////////////////////////////////////


i want the display to be in real number format......how to solve it ?

 

[tgq]

- put braces
- initialize variables first

 

[ee_cchac]

So, doesn't matter,

would anyone tell me how to calculate the real number is ok....

i just want to display a real number. however, i wm not going to display computer screen. i want to display it onto my dev. kit.

so thz

 

[vdaniel]

Maybe the problem is how you output your real number. You can use

printf("%3.2f", x);

This will output three digits before and two after the decimal point.

I use CodeVision AVR, and by redefinng the putchar() function, can use the printf() with any kind of output device. It can be LCD display, UART and so on.

Varuzhan

 

[ee_cchac]

Thank You for yr reply...and..how about using IAR ?

is it still work ? and i am using a function to release the output on LCD display....i can only pass a parameter into that function.....any good suggestion to solve my problem ?

 

[vdaniel]

I never worked with IAR, but I think, that this trick with redefined putchar(), works with other compilers too. I use it as well in Kail for LPC2129 programming. My
Codevision code:

// Write a character to the USART Transmitter or LCD

void putchar(char c)
{
if (PrintToLCDb)
lcd_putchar(LCD_Code(c));
else if (PrintToUSART1) {
putchar1(c);
delay_ms(10);
}
else {
while ((UCSR0A & DATA_REGISTER_EMPTY)==0);
EN0 = 1;
UDR0=c;
while ((UCSR0A & TX_COMPLETE) == 0);
EN0 = 0;
UCSR0A |= TX_COMPLETE;
}
}

using PrintToLCD and PrintToUSART1 variables, you can force
the printf() to work with any output device.

Varuzhan