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🩹 Clock-based planner trapezoidal nominal_rate (#26881)

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John Robertson 2024-07-13 17:47:46 +01:00 committed by GitHub
parent c961f3ab2b
commit 228179e09b
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GPG Key ID: B5690EEEBB952194
5 changed files with 18 additions and 17 deletions

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@ -53,12 +53,11 @@ typedef uint64_t hal_timer_t;
#if ENABLED(I2S_STEPPER_STREAM)
#define STEPPER_TIMER_PRESCALE 1
#define STEPPER_TIMER_RATE 250000 // 250khz, 4µs pulses of i2s word clock
#define STEPPER_TIMER_TICKS_PER_US ((STEPPER_TIMER_RATE) / 1000000) // stepper timer ticks per µs // wrong would be 0.25
#else
#define STEPPER_TIMER_PRESCALE 40
#define STEPPER_TIMER_RATE ((HAL_TIMER_RATE) / (STEPPER_TIMER_PRESCALE)) // frequency of stepper timer, 2MHz
#define STEPPER_TIMER_TICKS_PER_US ((STEPPER_TIMER_RATE) / 1000000) // stepper timer ticks per µs
#endif
#define STEPPER_TIMER_TICKS_PER_US ((STEPPER_TIMER_RATE) / 1000000) // stepper timer ticks per µs
#define STEP_TIMER_MIN_INTERVAL 8 // minimum time in µs between stepper interrupts

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@ -41,7 +41,7 @@ typedef uint32_t hal_timer_t;
#define FTM0_TIMER_PRESCALE_BITS 0b011
#define FTM1_TIMER_PRESCALE_BITS 0b010
#define FTM0_TIMER_RATE (F_BUS / (FTM0_TIMER_PRESCALE)) // 60MHz / 8 = 7500kHz
#define FTM0_TIMER_RATE (F_BUS / (FTM0_TIMER_PRESCALE)) // 60MHz / 8 = 7.5MHz
#define FTM1_TIMER_RATE (F_BUS / (FTM1_TIMER_PRESCALE)) // 60MHz / 4 = 15MHz
#define HAL_TIMER_RATE (FTM0_TIMER_RATE)

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@ -729,8 +729,6 @@ void Planner::init() {
#endif
#endif
#define MINIMAL_STEP_RATE 120
/**
* Get the current block for processing
* and mark the block as busy.
@ -796,13 +794,9 @@ void Planner::calculate_trapezoid_for_block(block_t * const block, const_float_t
uint32_t initial_rate = entry_speed ? LROUND(entry_speed * spmm) : block->initial_rate,
final_rate = LROUND(exit_speed * spmm);
// Removing code to constrain values produces judder in direction-switching moves because the
// current discrete stepping math diverges from physical motion under constant acceleration
// when acceleration_steps_per_s2 is large compared to initial/final_rate.
NOLESS(initial_rate, uint32_t(MINIMAL_STEP_RATE));
NOLESS(final_rate, uint32_t(MINIMAL_STEP_RATE));
NOMORE(initial_rate, block->nominal_rate); // NOTE: The nominal rate may be less than MINIMAL_STEP_RATE!
NOMORE(final_rate, block->nominal_rate);
NOLESS(initial_rate, stepper.minimal_step_rate);
NOLESS(final_rate, stepper.minimal_step_rate);
NOLESS(block->nominal_rate, stepper.minimal_step_rate);
#if ANY(S_CURVE_ACCELERATION, LIN_ADVANCE)
// If we have some plateau time, the cruise rate will be the nominal rate

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@ -2201,12 +2201,10 @@ hal_timer_t Stepper::calc_timer_interval(uint32_t step_rate) {
#ifdef CPU_32_BIT
// A fast processor can just do integer division
constexpr uint32_t min_step_rate = uint32_t(STEPPER_TIMER_RATE) / HAL_TIMER_TYPE_MAX;
return step_rate > min_step_rate ? uint32_t(STEPPER_TIMER_RATE) / step_rate : HAL_TIMER_TYPE_MAX;
return step_rate > minimal_step_rate ? uint32_t(STEPPER_TIMER_RATE) / step_rate : HAL_TIMER_TYPE_MAX;
#else
constexpr uint32_t min_step_rate = (F_CPU) / 500000U; // i.e., 32 or 40
if (step_rate >= 0x0800) { // higher step rate
// AVR is able to keep up at around 65kHz Stepping ISR rate at most.
// So values for step_rate > 65535 might as well be truncated.
@ -2220,8 +2218,8 @@ hal_timer_t Stepper::calc_timer_interval(uint32_t step_rate) {
const uint8_t gain = uint8_t(pgm_read_byte(table_address + 2));
return base - MultiU8X8toH8(uint8_t(step_rate & 0x00FF), gain);
}
else if (step_rate > min_step_rate) { // lower step rates
step_rate -= min_step_rate; // Correct for minimal speed
else if (step_rate > minimal_step_rate) { // lower step rates
step_rate -= minimal_step_rate; // Correct for minimal speed
const uintptr_t table_address = uintptr_t(&speed_lookuptable_slow[uint8_t(step_rate >> 3)]);
return uint16_t(pgm_read_word(table_address))
- ((uint16_t(pgm_read_word(table_address + 2)) * uint8_t(step_rate & 0x0007)) >> 3);

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@ -295,6 +295,16 @@ class Stepper {
public:
// The minimal step rate ensures calculations stay within limits
// and avoid the most unreasonably slow step rates.
static constexpr uint32_t minimal_step_rate = (
#ifdef CPU_32_BIT
_MAX((STEPPER_TIMER_RATE) / HAL_TIMER_TYPE_MAX, 1U) // 32-bit shouldn't go below 1
#else
(F_CPU) / 500000U // AVR shouldn't go below 32 (16MHz) or 40 (20MHz)
#endif
);
#if ANY(HAS_EXTRA_ENDSTOPS, Z_STEPPER_AUTO_ALIGN)
static bool separate_multi_axis;
#endif