/*--------------------------------------------------------------------------*/
ISR(TIMER0_A1, rtimer_a01_isr)
{
/* store the IV register as any read/write resets interrupt flags */
uint16_t ivreg = TA0IV;
if(ivreg & TA0IV_TACCR1) {
/* rtimer interrupt */
TA0CCTL1 &= ~CCIFG;
watchdog_start();
/* check for and run any pending rtimers */
rtimer_run_next();
/* also check for any pending events and wake up if needed */
if(process_nevents() > 0) {
LPM4_EXIT;
}
watchdog_stop();
} else if(ivreg & TA0IV_TACCR2) {
/* simple pwm interrupt */
TA0CCTL2 &= ~CCIFG;
if(spwm.on_time > 0) {
if(spwm.on_time == period) {
TA0CCTL2 &= ~CCIE; /* no need for interrupt, is at 100% DC */
/* SIMPLE_PWM_PORT(OUT) |= (1 << spwm.pin);*/
pwm_on_cb();
} else {
/* normal on-case */
if(period_end) {
period_end = 0;
TA0CCR2 = TAR + spwm.on_time;
/* SIMPLE_PWM_PORT(OUT) |= (1 << spwm.pin);*/
pwm_off_cb();
} else {
period_end = 1;
TA0CCR2 = TAR + (period - spwm.on_time);
/* SIMPLE_PWM_PORT(OUT) &= ~(1 << spwm.pin);*/
pwm_on_cb();
}
}
}
}
}
/*
* set pwm on at a duty cycle expressed in percent from 0 to 100. If crucial,
* calculate your own pulsetime and use that function due to rounding errors in
* this function.
*/
void
simple_pwm_on(uint8_t dc)
{
if(dc > 100) {
return;
}
if(dc == 100) {
TA0CCTL2 &= ~CCIE; /* no need for interrupt */
spwm.on_time = period;
/* SIMPLE_PWM_PORT(OUT) |= (1 << spwm.pin);*/
pwm_on_cb();
} else if(dc == 0) {
TA0CCTL2 &= ~CCIE; /* no need for interrupt */
spwm.on_time = 0;
/* SIMPLE_PWM_PORT(OUT) &= ~(1 << spwm.pin);*/
pwm_off_cb();
} else {
/* convert duty cycle to PWM clock ticks */
uint8_t finetime = (dc * period) / 100;
if(finetime == 0 && dc != 0) {
/* rounding errors, go for minimum-like */
finetime = 2;
}
/* set up a compare match for the next PWM period */
TA0CCR2 = TAR + finetime;
TA0CCTL2 = CCIE;
spwm.on_time = finetime;
}
}
/*
* set pwm on at a specified pulsetime measured in SIMPLE_PWM_SECOND ticks/s.
*
* The period is (SIMPLE_PWM_SECOND / SIMPLE_PWM_FREQ) - 1, measured in the
* same number of ticks/s. Default is 128 Hz and 32768 ticks/s, leaving us w
* 255 ticks/period, so the range becomes 0..255.
* Use this for precision work, eg a servo motor.
*/
void
simple_pwm_pulsetime(uint16_t finetime)
{
if(finetime >= period) {
TA0CCTL2 &= ~CCIE; /* no need for interrupt */
spwm.on_time = period;
/* SIMPLE_PWM_PORT(OUT) |= (1 << spwm.pin);*/
pwm_on_cb();
} else if(finetime == 0) {
TA0CCTL2 &= ~CCIE; /* no need for interrupt */
spwm.on_time = 0;
/* SIMPLE_PWM_PORT(OUT) &= ~(1 << spwm.pin);*/
pwm_off_cb();
} else {
/* set up a compare match for the next PWM period */
TA0CCR2 = TAR + finetime;
TA0CCTL2 = CCIE;
spwm.on_time = finetime;
}
}
