Maskinnära programmering 6B2266

#pragma origin 4
interrupt int_server( void )
{
int_save_registers
if( RBIF == 1 ) /* is it the RB pin change-interrupt? */
{ /* this time it's obvius that it is! */
/* read encoder new value */
trans.0 = quad_A;
trans.1 = quad_B;
/* compare with old value */
if( (trans == 0b00.01) && (count != 255) ) count ++;
if( (trans == 0b01.00) && (count != 0) ) count --;
/* replace old value with new value */
trans.2 = trans.0;
trans.3 = trans.1;
RBIF = 0; /* Reset RB-change flag before leaving */
}
int_restore_registers
}
void main( void )
{
/* the main program */
char speed;
CM0=1; CM1=1; CM2=1; /* no comparators on PORTA */
OPTION.7 = 0; /* internal pullup resistors on */
TRISA.1 = 0; /* PA1 is output. Motor GND. */
PORTA.1 = 0; /* Motor GND = 0 */
TRISB = 0b11000000; /* only inputs quad_A and quad_B */
trans = 0;
speed = 0;
RBIE = 1; /* local enable */
GIE = 1; /* global enable */
/* Settings CCP1 PWM-mode */
PR2 = 255;
TRISB.3 = 0; /* CCP1 is output (RB3-pin) */
T2CON = 0b0.0000.1.00;
/* 0, 0000 (1:1 postscale), 1 (TMR2 on), 00 (1:1 prescale) */
CCP1CON = 0b00.0.0.1111;
/* --, 0 (CCP1X), 0 (CCP1Y), 1111 (PWMmode 11xx) */
while(1)
{
speed = count;
CCPR1L = speed; /* new PWM-value */
}
}
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