Hello everyone, please excuse my ignorance on this topic but I have really
been trying to figure this out and I'm in need of assistance.  I am trying
to produce a sine wave output with a 16C774.  I am using CCS's compiler and
they have sine function implemented but I feel that I don't need the
accuracy (floating point) that it provides nor the memory it uses.  I have
looked at some assembly code that Eric Smith developed using a Sine table
and I think that it will be the most efficient.  What I will be doing is
writing the result to an 8-bit D/A converter and sweeping through each of
the 256 steps.  I think that this resolution is more than enough for my
application.

Here is my problem, I'm very new to the PIC and especially the compiler.  I
tried entering the code found here
http://www.brouhaha.com/~eric/pic/sine.html and I can't figure out for the
life of me how to get it to compile.  On this webpage it is not really clear
on the input and the output either.  Can someone point me in the right
direction so that I can get my code to compile?

Also, as an aside.  In CCS I was having problems at the end of my main
function because it put the PIC into sleep mode.  I put an empty do-while
loop at the end to allow the Interrupts to continue to run.  Is this the
right way to end in my situation or is there a better way?

Thanks,
Jeff Frey

Please also RTP so that I don't overlook any replies in the PICList.

Here is my code:

#include "o:\projects\safari\Safari.h"

/// The following are manually added definitions
#byte PORTB = 6
#define ALL_OUT 0
#define ALL_IN  0xff

int angle;

#int_rtcc
rtcc_isr() {

#asm

sinetbl:
        addwf   pc
        retlw    000h,003h,006h,009h,00ch,010h,013h,016h
        retlw    019h,01ch,01fh,022h,025h,028h,02bh,02eh
        retlw    031h,033h,036h,039h,03ch,03fh,041h,044h
        retlw    047h,049h,04ch,04eh,051h,053h,055h,058h
        retlw    05ah,05ch,05eh,060h,062h,064h,066h,068h
        retlw    06ah,06bh,06dh,06fh,070h,071h,073h,074h
        retlw    075h,076h,078h,079h,07ah,07ah,07bh,07ch
        retlw    07dh,07dh,07eh,07eh,07eh,07fh,07fh,07fh
        retlw    07fh
sine:   movwf   temp    ; save arg
        btfsc   temp,6  ; is arg in the 2nd or 4th quadrant?
        sublw   0       ; yes, complement it to reduce to 1st or 3rd
        andlw   07fh    ; reduce to 1st quadrant
        call    sinetbl ; get magnitude
        btfsc   temp,7  ; was it 3rd or 4th quadrant?
        sublw   0       ; yes, complement result
        return

#endasm

return;
}

#int_adcc
adc_isr() {

}

#int_eeprom
eeprom_isr() {

}

#int_timer1
timer1_isr() {

}

#int_timer2
timer2_isr() {

}



void main() {

   angle = 10;
   setup_adc_ports(A_ANALOG);
   setup_adc(ADC_CLOCK_DIV_2);
   setup_spi(FALSE);
   setup_psp(PSP_DISABLED);
   setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
//   setup_timer_1(T1_INTERNAL|T1_DIV_BY_1);
//   setup_timer_2(T2_DIV_BY_16,10,1);
   setup_ccp1(CCP_OFF);
   setup_ccp2(CCP_OFF);
   enable_interrupts(INT_RTCC);
//   enable_interrupts(INT_ADC);
//   enable_interrupts(INT_EEPROM);
//   enable_interrupts(INT_TIMER1);
//   enable_interrupts(INT_TIMER2);
   enable_interrupts(global);

   set_tris_b(ALL_OUT);    // Set all pins on PORTB as Outputs
   PORTB = 0;              // Set all pins on PORTB Low

   angle = 0;              // Initialize angle to 0 degrees
    do {

    } while(TRUE);

}

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