Vaisala PMB100 Bedienungsanleitung PDF herunterladen (Seite 14)

USER'S GUIDE_______________________________________________________________________

14 ___________________________________________________________________ M010035EN-A

The form of coefficients (32-bit signed integer) in the eeprom:

MSB LSB MSB LSB MSB LSB MSB LSB

eeprom: byte_0 xxxxxxxx byte_1 xxxxxxxx byte_2 xxxxxxxx byte_3 xxxxxxxx

long_int: bit_31 xxxxxxxx bit_23 xxxxxxxx bit_15 xxxxxxxx bit_7 xxxxxxxx bit_0

MSB LSB

32-bit signed integer → FLOAT (1.0...-1.0)

float=signed_long_int/2^31

In following there is an example of C-program to convert the 32 bit

coefficients to floating point numbers.

unsigned char read_eeprom(addr)

{

/* eeprom read routine */

return(read_data);

}

/*------------------------------------------------------

-------------------- -------------------*/

void read_long_int( char addr, long int *coef )

{

unsigned char *pointer=(char*)coef;

*pointer++=read_eeprom(addr++);

*pointer=read_eeprom(addr);

}

/*------------------------------------------------------

-------------------- -------------------*/

void main(void)

{

long int long_coef=0; /* signed long integer

(32 bit) */

float float_coef=0.;

read_long_int(14,&long_coef);

float_coef=(float)long_coef/0x80000000;

printf("Float is %e\r\n",float_coef);

}

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Vaisala PMB100 Bedienungsanleitung Seite 14