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Improve pulse timing and step reliability (#16128)

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This commit is contained in:
Jason Smith 2019-12-19 00:38:48 -08:00 committed by Scott Lahteine
parent 5f06f42ccd
commit 1bad8f1b17
5 changed files with 128 additions and 105 deletions
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12
Marlin/Configuration_adv.h
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@ -1548,12 +1548,12 @@
/** /**
* Maximum stepping rate (in Hz) the stepper driver allows * Maximum stepping rate (in Hz) the stepper driver allows
* If undefined, defaults to 1MHz / (2 * MINIMUM_STEPPER_PULSE) * If undefined, defaults to 1MHz / (2 * MINIMUM_STEPPER_PULSE)
* 500000 : Maximum for A4988 stepper driver * 5000000 : Maximum for TMC2xxx stepper drivers
* 400000 : Maximum for TMC2xxx stepper drivers * 1000000 : Maximum for LV8729 stepper driver
* 250000 : Maximum for DRV8825 stepper driver * 500000 : Maximum for A4988 stepper driver
* 200000 : Maximum for LV8729 stepper driver * 250000 : Maximum for DRV8825 stepper driver
* 150000 : Maximum for TB6600 stepper driver * 150000 : Maximum for TB6600 stepper driver
* 15000 : Maximum for TB6560 stepper driver * 15000 : Maximum for TB6560 stepper driver
* *
* Override the default value based on the driver type set in Configuration.h. * Override the default value based on the driver type set in Configuration.h.
*/ */

14
Marlin/src/inc/Conditionals_post.h
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@ -595,11 +595,7 @@
#elif HAS_DRIVER(A4988) || HAS_DRIVER(A5984) #elif HAS_DRIVER(A4988) || HAS_DRIVER(A5984)
#define MINIMUM_STEPPER_PULSE 1 #define MINIMUM_STEPPER_PULSE 1
#elif TRINAMICS #elif TRINAMICS
#if ENABLED(LIN_ADVANCE) && (HAS_TMC_STANDALONE_E_DRIVER || (HAS_TMC_E_DRIVER && DISABLED(SQUARE_WAVE_STEPPING))) #define MINIMUM_STEPPER_PULSE 0
#define MINIMUM_STEPPER_PULSE 1
#else
#define MINIMUM_STEPPER_PULSE 0
#endif
#elif HAS_DRIVER(LV8729) #elif HAS_DRIVER(LV8729)
#define MINIMUM_STEPPER_PULSE 0 #define MINIMUM_STEPPER_PULSE 0
#else #else
@ -612,14 +608,14 @@
#define MAXIMUM_STEPPER_RATE 15000 #define MAXIMUM_STEPPER_RATE 15000
#elif HAS_DRIVER(TB6600) #elif HAS_DRIVER(TB6600)
#define MAXIMUM_STEPPER_RATE 150000 #define MAXIMUM_STEPPER_RATE 150000
#elif HAS_DRIVER(LV8729)
#define MAXIMUM_STEPPER_RATE 200000
#elif HAS_DRIVER(DRV8825) #elif HAS_DRIVER(DRV8825)
#define MAXIMUM_STEPPER_RATE 250000 #define MAXIMUM_STEPPER_RATE 250000
#elif TRINAMICS
#define MAXIMUM_STEPPER_RATE 400000
#elif HAS_DRIVER(A4988) #elif HAS_DRIVER(A4988)
#define MAXIMUM_STEPPER_RATE 500000 #define MAXIMUM_STEPPER_RATE 500000
#elif HAS_DRIVER(LV8729)
#define MAXIMUM_STEPPER_RATE 1000000
#elif TRINAMICS
#define MAXIMUM_STEPPER_RATE 5000000
#else #else
#define MAXIMUM_STEPPER_RATE 250000 #define MAXIMUM_STEPPER_RATE 250000
#endif #endif

8
Marlin/src/inc/SanityCheck.h
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@ -2551,11 +2551,3 @@ static_assert( _ARR_TEST(3,0) && _ARR_TEST(3,1) && _ARR_TEST(3,2)
#error "SHOW_REMAINING_TIME currently requires a Graphical LCD." #error "SHOW_REMAINING_TIME currently requires a Graphical LCD."
#endif #endif
#endif #endif
#if ENABLED(LIN_ADVANCE) && MINIMUM_STEPPER_PULSE < 1
#if HAS_TMC_STANDALONE_E_DRIVER
#error "LIN_ADVANCE with TMC standalone driver on extruder requires MIMIMUM_STEPPER_PULSE >= 1"
#elif HAS_TMC_E_DRIVER && DISABLED(SQUARE_WAVE_STEPPING)
#error "LIN_ADVANCE with TMC driver on extruder requires SQUARE_WAVE_STEPPING or MINIMUM_STEPPER_PULSE >= 1"
#endif
#endif

162
Marlin/src/module/stepper.cpp
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@ -338,6 +338,17 @@ xyze_int8_t Stepper::count_direction{0};
#if DISABLED(MIXING_EXTRUDER) #if DISABLED(MIXING_EXTRUDER)
#define E_APPLY_STEP(v,Q) E_STEP_WRITE(stepper_extruder, v) #define E_APPLY_STEP(v,Q) E_STEP_WRITE(stepper_extruder, v)
#endif #endif
#define TIMER_SETUP_NS (CYCLES_TO_NS(TIMER_READ_ADD_AND_STORE_CYCLES))
#define PULSE_HIGH_TICK_COUNT hal_timer_t(NS_TO_PULSE_TIMER_TICKS(_MIN_PULSE_HIGH_NS - _MIN(_MIN_PULSE_HIGH_NS, TIMER_SETUP_NS)))
#define PULSE_LOW_TICK_COUNT hal_timer_t(NS_TO_PULSE_TIMER_TICKS(_MIN_PULSE_LOW_NS - _MIN(_MIN_PULSE_LOW_NS, TIMER_SETUP_NS)))
#define START_TIMED_PULSE(DIR) (end_tick_count = HAL_timer_get_count(PULSE_TIMER_NUM) + PULSE_##DIR##_TICK_COUNT)
#define AWAIT_TIMED_PULSE() while (HAL_timer_get_count(PULSE_TIMER_NUM) < end_tick_count) { }
#define START_HIGH_PULSE() START_TIMED_PULSE(HIGH)
#define START_LOW_PULSE() START_TIMED_PULSE(LOW)
#define AWAIT_HIGH_PULSE() AWAIT_TIMED_PULSE()
#define AWAIT_LOW_PULSE() AWAIT_TIMED_PULSE()
void Stepper::wake_up() { void Stepper::wake_up() {
// TCNT1 = 0; // TCNT1 = 0;
@ -1416,34 +1427,73 @@ void Stepper::stepper_pulse_phase_isr() {
// Just update the value we will get at the end of the loop // Just update the value we will get at the end of the loop
step_events_completed += events_to_do; step_events_completed += events_to_do;
// Get the timer count and estimate the end of the pulse
hal_timer_t pulse_end = HAL_timer_get_count(PULSE_TIMER_NUM) + hal_timer_t(MIN_PULSE_TICKS);
const hal_timer_t added_step_ticks = hal_timer_t(ADDED_STEP_TICKS);
// Take multiple steps per interrupt (For high speed moves) // Take multiple steps per interrupt (For high speed moves)
do { bool firstStep = true;
xyze_bool_t step_needed{0};
hal_timer_t end_tick_count;
do {
#define _APPLY_STEP(AXIS) AXIS ##_APPLY_STEP #define _APPLY_STEP(AXIS) AXIS ##_APPLY_STEP
#define _INVERT_STEP_PIN(AXIS) INVERT_## AXIS ##_STEP_PIN #define _INVERT_STEP_PIN(AXIS) INVERT_## AXIS ##_STEP_PIN
// Determine if pulses are needed
#define PULSE_PREP(AXIS) do{ \
delta_error[_AXIS(AXIS)] += advance_dividend[_AXIS(AXIS)]; \
step_needed[_AXIS(AXIS)] = (delta_error[_AXIS(AXIS)] >= 0); \
if (step_needed[_AXIS(AXIS)]) { \
count_position[_AXIS(AXIS)] += count_direction[_AXIS(AXIS)]; \
delta_error[_AXIS(AXIS)] -= advance_divisor; \
} \
}while(0)
// Start an active pulse, if Bresenham says so, and update position // Start an active pulse, if Bresenham says so, and update position
#define PULSE_START(AXIS) do{ \ #define PULSE_START(AXIS) do{ \
delta_error[_AXIS(AXIS)] += advance_dividend[_AXIS(AXIS)]; \ if (step_needed[_AXIS(AXIS)]) { \
if (delta_error[_AXIS(AXIS)] >= 0) { \
_APPLY_STEP(AXIS)(!_INVERT_STEP_PIN(AXIS), 0); \ _APPLY_STEP(AXIS)(!_INVERT_STEP_PIN(AXIS), 0); \
count_position[_AXIS(AXIS)] += count_direction[_AXIS(AXIS)]; \
} \ } \
}while(0) }while(0)
// Stop an active pulse, if any, and adjust error term // Stop an active pulse, if any, and adjust error term
#define PULSE_STOP(AXIS) do { \ #define PULSE_STOP(AXIS) do { \
if (delta_error[_AXIS(AXIS)] >= 0) { \ if (step_needed[_AXIS(AXIS)]) { \
delta_error[_AXIS(AXIS)] -= advance_divisor; \
_APPLY_STEP(AXIS)(_INVERT_STEP_PIN(AXIS), 0); \ _APPLY_STEP(AXIS)(_INVERT_STEP_PIN(AXIS), 0); \
} \ } \
}while(0) }while(0)
// Determine if pulses are needed
#if HAS_X_STEP
PULSE_PREP(X);
#endif
#if HAS_Y_STEP
PULSE_PREP(Y);
#endif
#if HAS_Z_STEP
PULSE_PREP(Z);
#endif
#if EITHER(LIN_ADVANCE, MIXING_EXTRUDER)
delta_error.e += advance_dividend.e;
if (delta_error.e >= 0) {
count_position.e += count_direction.e;
#if ENABLED(LIN_ADVANCE)
delta_error.e -= advance_divisor;
// Don't step E here - But remember the number of steps to perform
motor_direction(E_AXIS) ? --LA_steps : ++LA_steps;
#else
step_needed[E_AXIS] = delta_error.e >= 0;
#endif
}
#elif HAS_E0_STEP
PULSE_PREP(E);
#endif
#if (MINIMUM_STEPPER_PULSE || MAXIMUM_STEPPER_RATE) && DISABLED(I2S_STEPPER_STREAM)
if (firstStep)
firstStep = false;
else
AWAIT_LOW_PULSE();
#endif
// Pulse start // Pulse start
#if HAS_X_STEP #if HAS_X_STEP
PULSE_START(X); PULSE_START(X);
@ -1455,24 +1505,10 @@ void Stepper::stepper_pulse_phase_isr() {
PULSE_START(Z); PULSE_START(Z);
#endif #endif
// Pulse Extruders #if DISABLED(LIN_ADVANCE)
// Tick the E axis, correct error term and update position #if ENABLED(MIXING_EXTRUDER)
#if EITHER(LIN_ADVANCE, MIXING_EXTRUDER) if (step_needed[E_AXIS]) E_STEP_WRITE(mixer.get_next_stepper(), !INVERT_E_STEP_PIN);
delta_error.e += advance_dividend.e; #elif HAS_E0_STEP
if (delta_error.e >= 0) {
count_position.e += count_direction.e;
#if ENABLED(LIN_ADVANCE)
delta_error.e -= advance_divisor;
// Don't step E here - But remember the number of steps to perform
motor_direction(E_AXIS) ? --LA_steps : ++LA_steps;
#else // !LIN_ADVANCE && MIXING_EXTRUDER
// Don't adjust delta_error.e here!
// Being positive is the criteria for ending the pulse.
E_STEP_WRITE(mixer.get_next_stepper(), !INVERT_E_STEP_PIN);
#endif
}
#else // !LIN_ADVANCE && !MIXING_EXTRUDER
#if HAS_E0_STEP
PULSE_START(E); PULSE_START(E);
#endif #endif
#endif #endif
@ -1482,14 +1518,11 @@ void Stepper::stepper_pulse_phase_isr() {
#endif #endif
// TODO: need to deal with MINIMUM_STEPPER_PULSE over i2s // TODO: need to deal with MINIMUM_STEPPER_PULSE over i2s
#if MINIMUM_STEPPER_PULSE && DISABLED(I2S_STEPPER_STREAM) #if (MINIMUM_STEPPER_PULSE || MAXIMUM_STEPPER_RATE) && DISABLED(I2S_STEPPER_STREAM)
// Just wait for the requested pulse duration START_HIGH_PULSE();
while (HAL_timer_get_count(PULSE_TIMER_NUM) < pulse_end) { /* nada */ } AWAIT_HIGH_PULSE();
#endif #endif
// Add the delay needed to ensure the maximum driver rate is enforced
if (signed(added_step_ticks) > 0) pulse_end += hal_timer_t(added_step_ticks);
// Pulse stop // Pulse stop
#if HAS_X_STEP #if HAS_X_STEP
PULSE_STOP(X); PULSE_STOP(X);
@ -1503,31 +1536,26 @@ void Stepper::stepper_pulse_phase_isr() {
#if DISABLED(LIN_ADVANCE) #if DISABLED(LIN_ADVANCE)
#if ENABLED(MIXING_EXTRUDER) #if ENABLED(MIXING_EXTRUDER)
if (delta_error.e >= 0) { if (delta_error.e >= 0) {
delta_error.e -= advance_divisor; delta_error.e -= advance_divisor;
E_STEP_WRITE(mixer.get_stepper(), INVERT_E_STEP_PIN); E_STEP_WRITE(mixer.get_stepper(), INVERT_E_STEP_PIN);
} }
#else // !MIXING_EXTRUDER #else // !MIXING_EXTRUDER
#if HAS_E0_STEP #if HAS_E0_STEP
PULSE_STOP(E); PULSE_STOP(E);
#endif #endif
#endif
#endif // !MIXING_EXTRUDER
#endif // !LIN_ADVANCE #endif // !LIN_ADVANCE
// Decrement the count of pending pulses to do #if (MINIMUM_STEPPER_PULSE || MAXIMUM_STEPPER_RATE) && DISABLED(I2S_STEPPER_STREAM)
--events_to_do; if (events_to_do) START_LOW_PULSE();
#endif
// For minimum pulse time wait after stopping pulses also } while (--events_to_do);
if (events_to_do) {
// Just wait for the requested pulse duration
while (HAL_timer_get_count(PULSE_TIMER_NUM) < pulse_end) { /* nada */ }
#if MINIMUM_STEPPER_PULSE
// Add to the value, the time that the pulse must be active (to be used on the next loop)
pulse_end += hal_timer_t(MIN_PULSE_TICKS);
#endif
}
} while (events_to_do);
} }
// This is the last half of the stepper interrupt: This one processes and // This is the last half of the stepper interrupt: This one processes and
@ -1909,13 +1937,19 @@ uint32_t Stepper::stepper_block_phase_isr() {
DELAY_NS(MINIMUM_STEPPER_POST_DIR_DELAY); DELAY_NS(MINIMUM_STEPPER_POST_DIR_DELAY);
#endif #endif
// Get the timer count and estimate the end of the pulse //const hal_timer_t added_step_ticks = hal_timer_t(ADDED_STEP_TICKS);
hal_timer_t pulse_end = HAL_timer_get_count(PULSE_TIMER_NUM) + hal_timer_t(MIN_PULSE_TICKS);
const hal_timer_t added_step_ticks = hal_timer_t(ADDED_STEP_TICKS);
// Step E stepper if we have steps // Step E stepper if we have steps
bool firstStep = true;
hal_timer_t end_tick_count;
while (LA_steps) { while (LA_steps) {
#if (MINIMUM_STEPPER_PULSE || MAXIMUM_STEPPER_RATE) && DISABLED(I2S_STEPPER_STREAM)
if (firstStep)
firstStep = false;
else
AWAIT_LOW_PULSE();
#endif
// Set the STEP pulse ON // Set the STEP pulse ON
#if ENABLED(MIXING_EXTRUDER) #if ENABLED(MIXING_EXTRUDER)
@ -1925,16 +1959,16 @@ uint32_t Stepper::stepper_block_phase_isr() {
#endif #endif
// Enforce a minimum duration for STEP pulse ON // Enforce a minimum duration for STEP pulse ON
#if MINIMUM_STEPPER_PULSE #if (MINIMUM_STEPPER_PULSE || MAXIMUM_STEPPER_RATE)
// Just wait for the requested pulse duration START_HIGH_PULSE();
while (HAL_timer_get_count(PULSE_TIMER_NUM) < pulse_end) { /* nada */ }
#endif #endif
// Add the delay needed to ensure the maximum driver rate is enforced
if (signed(added_step_ticks) > 0) pulse_end += hal_timer_t(added_step_ticks);
LA_steps < 0 ? ++LA_steps : --LA_steps; LA_steps < 0 ? ++LA_steps : --LA_steps;
#if (MINIMUM_STEPPER_PULSE || MAXIMUM_STEPPER_RATE)
AWAIT_HIGH_PULSE();
#endif
// Set the STEP pulse OFF // Set the STEP pulse OFF
#if ENABLED(MIXING_EXTRUDER) #if ENABLED(MIXING_EXTRUDER)
E_STEP_WRITE(mixer.get_stepper(), INVERT_E_STEP_PIN); E_STEP_WRITE(mixer.get_stepper(), INVERT_E_STEP_PIN);
@ -1944,13 +1978,9 @@ uint32_t Stepper::stepper_block_phase_isr() {
// For minimum pulse time wait before looping // For minimum pulse time wait before looping
// Just wait for the requested pulse duration // Just wait for the requested pulse duration
if (LA_steps) { #if (MINIMUM_STEPPER_PULSE || MAXIMUM_STEPPER_RATE)
while (HAL_timer_get_count(PULSE_TIMER_NUM) < pulse_end) { /* nada */ } if (LA_steps) START_LOW_PULSE();
#if MINIMUM_STEPPER_PULSE #endif
// Add to the value, the time that the pulse must be active (to be used on the next loop)
pulse_end += hal_timer_t(MIN_PULSE_TICKS);
#endif
}
} // LA_steps } // LA_steps
return interval; return interval;

37
Marlin/src/module/stepper.h
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@ -57,6 +57,7 @@
// //
#ifdef CPU_32_BIT #ifdef CPU_32_BIT
#define TIMER_READ_ADD_AND_STORE_CYCLES 34UL
// The base ISR takes 792 cycles // The base ISR takes 792 cycles
#define ISR_BASE_CYCLES 792UL #define ISR_BASE_CYCLES 792UL
@ -85,6 +86,7 @@
#define ISR_STEPPER_CYCLES 16UL #define ISR_STEPPER_CYCLES 16UL
#else #else
#define TIMER_READ_ADD_AND_STORE_CYCLES 13UL
// The base ISR takes 752 cycles // The base ISR takes 752 cycles
#define ISR_BASE_CYCLES 752UL #define ISR_BASE_CYCLES 752UL
@ -116,43 +118,32 @@
// Add time for each stepper // Add time for each stepper
#if HAS_X_STEP #if HAS_X_STEP
#define ISR_START_X_STEPPER_CYCLES ISR_START_STEPPER_CYCLES
#define ISR_X_STEPPER_CYCLES ISR_STEPPER_CYCLES #define ISR_X_STEPPER_CYCLES ISR_STEPPER_CYCLES
#else #else
#define ISR_START_X_STEPPER_CYCLES 0UL
#define ISR_X_STEPPER_CYCLES 0UL #define ISR_X_STEPPER_CYCLES 0UL
#endif #endif
#if HAS_Y_STEP #if HAS_Y_STEP
#define ISR_START_Y_STEPPER_CYCLES ISR_START_STEPPER_CYCLES
#define ISR_Y_STEPPER_CYCLES ISR_STEPPER_CYCLES #define ISR_Y_STEPPER_CYCLES ISR_STEPPER_CYCLES
#else #else
#define ISR_START_Y_STEPPER_CYCLES 0UL #define ISR_START_Y_STEPPER_CYCLES 0UL
#define ISR_Y_STEPPER_CYCLES 0UL #define ISR_Y_STEPPER_CYCLES 0UL
#endif #endif
#if HAS_Z_STEP #if HAS_Z_STEP
#define ISR_START_Z_STEPPER_CYCLES ISR_START_STEPPER_CYCLES
#define ISR_Z_STEPPER_CYCLES ISR_STEPPER_CYCLES #define ISR_Z_STEPPER_CYCLES ISR_STEPPER_CYCLES
#else #else
#define ISR_START_Z_STEPPER_CYCLES 0UL
#define ISR_Z_STEPPER_CYCLES 0UL #define ISR_Z_STEPPER_CYCLES 0UL
#endif #endif
// E is always interpolated, even for mixing extruders // E is always interpolated, even for mixing extruders
#define ISR_START_E_STEPPER_CYCLES ISR_START_STEPPER_CYCLES
#define ISR_E_STEPPER_CYCLES ISR_STEPPER_CYCLES #define ISR_E_STEPPER_CYCLES ISR_STEPPER_CYCLES
// If linear advance is disabled, the loop also handles them // If linear advance is disabled, the loop also handles them
#if DISABLED(LIN_ADVANCE) && ENABLED(MIXING_EXTRUDER) #if DISABLED(LIN_ADVANCE) && ENABLED(MIXING_EXTRUDER)
#define ISR_START_MIXING_STEPPER_CYCLES ((MIXING_STEPPERS) * (ISR_START_STEPPER_CYCLES))
#define ISR_MIXING_STEPPER_CYCLES ((MIXING_STEPPERS) * (ISR_STEPPER_CYCLES)) #define ISR_MIXING_STEPPER_CYCLES ((MIXING_STEPPERS) * (ISR_STEPPER_CYCLES))
#else #else
#define ISR_START_MIXING_STEPPER_CYCLES 0UL
#define ISR_MIXING_STEPPER_CYCLES 0UL #define ISR_MIXING_STEPPER_CYCLES 0UL
#endif #endif
// Calculate the minimum time to start all stepper pulses in the ISR loop
#define MIN_ISR_START_LOOP_CYCLES (ISR_START_X_STEPPER_CYCLES + ISR_START_Y_STEPPER_CYCLES + ISR_START_Z_STEPPER_CYCLES + ISR_START_E_STEPPER_CYCLES + ISR_START_MIXING_STEPPER_CYCLES)
// And the total minimum loop time, not including the base // And the total minimum loop time, not including the base
#define MIN_ISR_LOOP_CYCLES (ISR_X_STEPPER_CYCLES + ISR_Y_STEPPER_CYCLES + ISR_Z_STEPPER_CYCLES + ISR_E_STEPPER_CYCLES + ISR_MIXING_STEPPER_CYCLES) #define MIN_ISR_LOOP_CYCLES (ISR_X_STEPPER_CYCLES + ISR_Y_STEPPER_CYCLES + ISR_Z_STEPPER_CYCLES + ISR_E_STEPPER_CYCLES + ISR_MIXING_STEPPER_CYCLES)
@ -170,14 +161,28 @@
// adding the "start stepper pulse" code section execution cycles to account for that not all // adding the "start stepper pulse" code section execution cycles to account for that not all
// pulses start at the beginning of the loop, so an extra time must be added to compensate so // pulses start at the beginning of the loop, so an extra time must be added to compensate so
// the last generated pulse (usually the extruder stepper) has the right length // the last generated pulse (usually the extruder stepper) has the right length
#if HAS_DRIVER(LV8729) && MINIMUM_STEPPER_PULSE == 0 #if MINIMUM_STEPPER_PULSE && MAXIMUM_STEPPER_RATE
#define MIN_PULSE_TICKS ((((PULSE_TIMER_TICKS_PER_US) + 1) / 2) + ((MIN_ISR_START_LOOP_CYCLES) / uint32_t(PULSE_TIMER_PRESCALE))) constexpr uint32_t _MIN_STEP_PERIOD_NS = 1000000000UL / MAXIMUM_STEPPER_RATE;
constexpr uint32_t _MIN_PULSE_HIGH_NS = 1000UL * MINIMUM_STEPPER_PULSE;
constexpr uint32_t _MIN_PULSE_LOW_NS = _MAX((_MIN_STEP_PERIOD_NS - _MIN(_MIN_STEP_PERIOD_NS, _MIN_PULSE_HIGH_NS)), _MIN_PULSE_HIGH_NS);
#elif MINIMUM_STEPPER_PULSE
// Assume 50% duty cycle
constexpr uint32_t _MIN_STEP_PERIOD_NS = 1000000000UL / MAXIMUM_STEPPER_RATE;
constexpr uint32_t _MIN_PULSE_HIGH_NS = 1000UL * MINIMUM_STEPPER_PULSE;
constexpr uint32_t _MIN_PULSE_LOW_NS = _MIN_PULSE_HIGH_NS;
#elif MAXIMUM_STEPPER_RATE
// Assume 50% duty cycle
constexpr uint32_t _MIN_PULSE_HIGH_NS = 500000000UL / MAXIMUM_STEPPER_RATE;
constexpr uint32_t _MIN_PULSE_LOW_NS = _MIN_PULSE_HIGH_NS;
#else #else
#define MIN_PULSE_TICKS (((PULSE_TIMER_TICKS_PER_US) * uint32_t(MINIMUM_STEPPER_PULSE)) + ((MIN_ISR_START_LOOP_CYCLES) / uint32_t(PULSE_TIMER_PRESCALE))) #error "Expected at least one of MINIMUM_STEPPER_PULSE or MAXIMUM_STEPPER_RATE to be defined"
#endif #endif
// Calculate the extra ticks of the PULSE timer between step pulses // TODO: NS_TO_PULSE_TIMER_TICKS has some rounding issues:
#define ADDED_STEP_TICKS (((MIN_STEPPER_PULSE_CYCLES) / (PULSE_TIMER_PRESCALE)) - (MIN_PULSE_TICKS)) // 1. PULSE_TIMER_TICKS_PER_US rounds to an integer, which loses 20% of the count for a 2.5 MHz pulse tick (such as for LPC1768)
// 2. The math currently rounds down to the closes tick. Perhaps should round up.
constexpr uint32_t NS_TO_PULSE_TIMER_TICKS(uint32_t NS) { return PULSE_TIMER_TICKS_PER_US * (NS) / 1000UL; }
#define CYCLES_TO_NS(CYC) (1000UL * (CYC) / ((F_CPU) / 1000000))
// But the user could be enforcing a minimum time, so the loop time is // But the user could be enforcing a minimum time, so the loop time is
#define ISR_LOOP_CYCLES (ISR_LOOP_BASE_CYCLES + _MAX(MIN_STEPPER_PULSE_CYCLES, MIN_ISR_LOOP_CYCLES)) #define ISR_LOOP_CYCLES (ISR_LOOP_BASE_CYCLES + _MAX(MIN_STEPPER_PULSE_CYCLES, MIN_ISR_LOOP_CYCLES))