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🐛 Fix, improve PWM on AVR (MarlinFirmware#23520)
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descipher authored and mh-dm committed May 15, 2022
1 parent e789089 commit 5741a5f
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Showing 2 changed files with 25 additions and 14 deletions.
23 changes: 16 additions & 7 deletions Marlin/src/HAL/AVR/fast_pwm.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -61,19 +61,23 @@ Timer get_pwm_timer(const pin_t pin) {
switch (digitalPinToTimer(pin)) {
#ifdef TCCR0A
IF_DISABLED(AVR_AT90USB1286_FAMILY, case TIMER0A:)
case TIMER0B:
#endif
#ifdef TCCR1A
case TIMER1A: case TIMER1B:
#endif

break; // Protect reserved timers (TIMER0 & TIMER1)

#ifdef TCCR0A
case TIMER0B: // Protected timer, but allow setting the duty cycle on OCR0B for pin D4 only
return Timer({ { &TCCR0A, nullptr, nullptr }, { (uint16_t*)&OCR0B, nullptr, nullptr }, nullptr, 0, 0, true, true });
#endif

#if HAS_TCCR2
case TIMER2:
return Timer({ { &TCCR2, nullptr, nullptr }, { (uint16_t*)&OCR2, nullptr, nullptr }, nullptr, 2, 0, true, false });
#elif ENABLED(USE_OCR2A_AS_TOP)
case TIMER2A: break; // protect TIMER2A since its OCR is used by TIMER2B
case TIMER2A: break; // Protect TIMER2A since its OCR is used by TIMER2B
case TIMER2B:
return Timer({ { &TCCR2A, &TCCR2B, nullptr }, { (uint16_t*)&OCR2A, (uint16_t*)&OCR2B, nullptr }, nullptr, 2, 1, true, false });
#elif defined(TCCR2A)
Expand Down Expand Up @@ -174,18 +178,23 @@ void set_pwm_frequency(const pin_t pin, const uint16_t f_desired) {

void set_pwm_duty(const pin_t pin, const uint16_t v, const uint16_t v_size/*=255*/, const bool invert/*=false*/) {
// If v is 0 or v_size (max), digitalWrite to LOW or HIGH.
// Note that digitalWrite also disables pwm output for us (sets COM bit to 0)
// Note that digitalWrite also disables PWM output for us (sets COM bit to 0)
if (v == 0)
digitalWrite(pin, invert);
else if (v == v_size)
digitalWrite(pin, !invert);
else {
Timer timer = get_pwm_timer(pin);
if (timer.isProtected) return; // Leave protected timer unchanged
if (timer.isPWM) {
_SET_COMnQ(timer.TCCRnQ, SUM_TERN(HAS_TCCR2, timer.q, timer.q == 2), COM_CLEAR_SET + invert); // COM20 is on bit 4 of TCCR2, so +1 for q==2
const uint16_t top = timer.n == 2 ? TERN(USE_OCR2A_AS_TOP, *timer.OCRnQ[0], 255) : *timer.ICRn;
_SET_OCRnQ(timer.OCRnQ, timer.q, uint16_t(uint32_t(v) * top / v_size)); // Scale 8/16-bit v to top value
if (timer.n == 0) {
TCCR0A |= _BV(COM0B1); // Only allow a TIMER0B select and OCR0B duty update for pin D4 outputs no frequency changes are permited.
OCR0B = v;
}
else if (!timer.isProtected) {
const uint16_t top = timer.n == 2 ? TERN(USE_OCR2A_AS_TOP, *timer.OCRnQ[0], 255) : *timer.ICRn;
_SET_COMnQ(timer.TCCRnQ, SUM_TERN(HAS_TCCR2, timer.q, timer.q == 2), COM_CLEAR_SET + invert); // COM20 is on bit 4 of TCCR2, so +1 for q==2
_SET_OCRnQ(timer.OCRnQ, timer.q, uint16_t(uint32_t(v) * top / v_size)); // Scale 8/16-bit v to top value
}
}
else
digitalWrite(pin, v < 128 ? LOW : HIGH);
Expand Down
16 changes: 9 additions & 7 deletions Marlin/src/module/planner.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -1244,10 +1244,6 @@ void Planner::recalculate() {
recalculate_trapezoids();
}

#if HAS_FAN && DISABLED(LASER_SYNCHRONOUS_M106_M107)
#define HAS_TAIL_FAN_SPEED 1
#endif

/**
* Apply fan speeds
*/
Expand Down Expand Up @@ -1308,8 +1304,9 @@ void Planner::check_axes_activity() {
xyze_bool_t axis_active = { false };
#endif

#if HAS_TAIL_FAN_SPEED
static uint8_t tail_fan_speed[FAN_COUNT] = ARRAY_N_1(FAN_COUNT, 255);
#if HAS_FAN && DISABLED(LASER_SYNCHRONOUS_M106_M107)
#define HAS_TAIL_FAN_SPEED 1
static uint8_t tail_fan_speed[FAN_COUNT] = ARRAY_N_1(FAN_COUNT, 128);
bool fans_need_update = false;
#endif

Expand Down Expand Up @@ -1395,7 +1392,12 @@ void Planner::check_axes_activity() {
// Update Fan speeds
// Only if synchronous M106/M107 is disabled
//
TERN_(HAS_TAIL_FAN_SPEED, if (fans_need_update) sync_fan_speeds(tail_fan_speed));
#if HAS_TAIL_FAN_SPEED
if (fans_need_update) {
sync_fan_speeds(tail_fan_speed);
fans_need_update = false;
}
#endif

TERN_(AUTOTEMP, autotemp_task());

Expand Down

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