void GrillPid::setOutputDevice(unsigned char outputDevice)
{
TIMSK1 = 0;
// Fast PWM Timer with TOP=ICR1 with no OC1x output
TCCR1A = bit(WGM11);
switch (outputDevice)
{
case PIDOUTPUT_Default:
case PIDOUTPUT_Fan:
_outputDevice = PIDOUTPUT_Fan;
// 64 prescaler
TCCR1B = bit(WGM13) | bit(WGM12) | bit(CS11) | bit(CS10);
// 511 TOP to be close to original 488Hz and allows OCR1B to be set to
// 512 to prevent COMB_vect from firing (which means no LOW when at 100%)
ICR1 = 511;
break;
case PIDOUTPUT_Servo:
_outputDevice = PIDOUTPUT_Servo;
// 8 prescaler gives us down to 30Hz with 0.5usec resolution
TCCR1B = bit(WGM13) | bit(WGM12) | bit(CS11);
// TOP = servo refresh
ICR1 = uSecToTicks(SERVO_REFRESH);
break;
}
// Interrupt on overflow, and OCB
TIMSK1 = bit(OCIE1B) | bit(TOIE1);
}
inline void GrillPid::commitServoOutput(void)
{
#if defined(GRILLPID_SERVO_ENABLED)
unsigned char output;
if (bit_is_set(_outputFlags, PIDFLAG_SERVO_ANY_MAX) && _pidOutput > 0)
output = 100;
else
output = _pidOutput;
if (bit_is_set(_outputFlags, PIDFLAG_INVERT_SERVO))
output = 100 - output;
// Get the output speed in 10x usec by LERPing between min and max
output = mappct(output, _minServoPos, _maxServoPos);
// Servo output is actually set on the next interrupt cycle
_servoOutput = uSecToTicks(10U * output);
#endif
}
inline void GrillPid::commitFanSpeed(void)
{
/* Long PWM period is 10 sec */
const unsigned int LONG_PWM_PERIOD = 10000;
const unsigned int PERIOD_SCALE = (LONG_PWM_PERIOD / TEMP_MEASURE_PERIOD);
calcExpMovingAverage(FANSPEED_AVG_SMOOTH, &FanSpeedAvg, _fanSpeed);
if (_outputDevice == PIDOUTPUT_Fan)
{
/* For anything above _minFanSpeed, do a nomal PWM write.
For below _minFanSpeed we use a "long pulse PWM", where
the pulse is 10 seconds in length. For each percent we are
emulating, run the fan for one interval. */
unsigned char output;
if (_fanSpeed >= _minFanSpeed)
{
output = _fanSpeed;
_longPwmTmr = 0;
}
else
{
// Simple PWM, ON for first [FanSpeed] intervals then OFF
// for the remainder of the period
if (((PERIOD_SCALE * _fanSpeed / _minFanSpeed) > _longPwmTmr))
output = _minFanSpeed;
else
output = 0;
if (++_longPwmTmr > (PERIOD_SCALE - 1))
_longPwmTmr = 0;
} /* long PWM */
if (_invertPwm)
output = _maxFanSpeed - output;
OCR1B = (unsigned int)output * 512 / 100;
}
else
{
// GrillPidOutput::Servo
unsigned char output;
if (_invertPwm)
output = 100 - _fanSpeed;
else
output = _fanSpeed;
// Get the output speed in 10x usec by LERPing between min and max
output = ((_maxFanSpeed - _minFanSpeed) * (unsigned int)output / 100) + _minFanSpeed;
OCR1B = uSecToTicks(10U * output);
}
#if defined(TIMER1_DEBUG)
SerialX.print("HMLG,0,");
SerialX.print(" ICR1="); SerialX.print(ICR1, DEC);
SerialX.print(" OCR1B="); SerialX.print(OCR1B, DEC);
SerialX.print(" TCCR1A=x"); SerialX.print(TCCR1A, HEX);
SerialX.print(" TCCR1B=x"); SerialX.print(TCCR1B, HEX);
SerialX.print(" TCCR1C=x"); SerialX.print(TCCR1C, HEX);
SerialX.print(" TIMSK1=x"); SerialX.print(TIMSK1, HEX);
if (ovf) { ovf = false; SerialX.print(" ovf"); }
if (rst) { SerialX.print(' '); SerialX.print(rst, DEC); rst = 0; }
if (bit_is_set(TIFR1, TOV1)) { SerialX.print(" TOV1"); TIFR1 = bit(TOV1); }
SerialX.nl();
#endif
}