Analog-to-Digital Converter - The HCS12/9S12: An Introduction to Software and Hardware Interfacing - page 620

temp2 5 (ATD0DR0 * 10) % 62; /* remainder part */

temp1 25 40; /* subtract the offset from the actual temperature */

if (temp1 , 0){ /* temperature is negative */

sign 5 1;

temp1 5 2 temp1; /* find the magnitude of temperature */

if (temp2) { /* remainder not zero */

temp1 22 ;

temp2 5 62 2 temp2;

}

}

fdigit 5 (temp2 * 10)/62; /* compute the fractional digit */

frem 5 (temp2 * 10) % 62;

if (frem . 31) {

fdigit 11 ;

if (fdigit 55 10) { /* round off the fractional digit */

fdigit 5 0;

temp1 11 ;

}

}

if (sign) {

ptr 5 &buf[1]; /* point to the first space to hold ASCII string */

buf[0] 5 0x2D; /* store minus sign as the first character */

}

else

ptr 5 &buf[0];

int2alpha(temp1,ptr); /* convert the integer part to ASCII string */

ptr 5 &buf[0];

while(*ptr) /* find the end of the integer string */

ptr 11 ;

*ptr 11 5 '.';

*ptr 11 5 fdigit 1 0x30;

*ptr 11 5 223; /* add a degree character */

*ptr 11 5 'C'; /* temperature in Celsius */

*ptr 5 0; /* terminate the temperature string */

cmd2lcd(0xC0); /* move cursor to 2nd row */

puts2lcd(blanks); /* clear the 2nd row */

cmd2lcd(0xC5); /* set cursor to column 5 row 2 */

puts2lcd(&buf[0]); /* output the temperature */

delayby100ms(2); /* wait for 0.2 seconds */

}

}
void openAD0(void)
{

ATD0CTL2 5 0xE0; /* enable AD0, fast ATD flag clear, power-down on wait */

ATD0CTL3 5 0x0A; /* perform one ATD conversion */

ATD0CTL4 5 0x25; /* prescaler set to 12, select four cycles sample time */

delayby10us(2);

}

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