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Diffstat (limited to 'Marlin/src/module/stepper.h')
| -rw-r--r-- | Marlin/src/module/stepper.h | 607 |
1 files changed, 607 insertions, 0 deletions
diff --git a/Marlin/src/module/stepper.h b/Marlin/src/module/stepper.h new file mode 100644 index 0000000..639a1b2 --- /dev/null +++ b/Marlin/src/module/stepper.h @@ -0,0 +1,607 @@ +/** + * Marlin 3D Printer Firmware + * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin] + * + * Based on Sprinter and grbl. + * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + * + */ +#pragma once + +/** + * stepper.h - stepper motor driver: executes motion plans of planner.c using the stepper motors + * Derived from Grbl + * + * Copyright (c) 2009-2011 Simen Svale Skogsrud + * + * Grbl is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * Grbl is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with Grbl. If not, see <https://www.gnu.org/licenses/>. + */ + +#include "../inc/MarlinConfig.h" + +#include "planner.h" +#include "stepper/indirection.h" +#ifdef __AVR__ + #include "speed_lookuptable.h" +#endif + +// Disable multiple steps per ISR +//#define DISABLE_MULTI_STEPPING + +// +// Estimate the amount of time the Stepper ISR will take to execute +// + +/** + * The method of calculating these cycle-constants is unclear. + * Most of them are no longer used directly for pulse timing, and exist + * only to estimate a maximum step rate based on the user's configuration. + * As 32-bit processors continue to diverge, maintaining cycle counts + * will become increasingly difficult and error-prone. + */ + +#ifdef CPU_32_BIT + /** + * Duration of START_TIMED_PULSE + * + * ...as measured on an LPC1768 with a scope and converted to cycles. + * Not applicable to other 32-bit processors, but as long as others + * take longer, pulses will be longer. For example the SKR Pro + * (stm32f407zgt6) requires ~60 cyles. + */ + #define TIMER_READ_ADD_AND_STORE_CYCLES 34UL + + // The base ISR takes 792 cycles + #define ISR_BASE_CYCLES 792UL + + // Linear advance base time is 64 cycles + #if ENABLED(LIN_ADVANCE) + #define ISR_LA_BASE_CYCLES 64UL + #else + #define ISR_LA_BASE_CYCLES 0UL + #endif + + // S curve interpolation adds 40 cycles + #if ENABLED(S_CURVE_ACCELERATION) + #define ISR_S_CURVE_CYCLES 40UL + #else + #define ISR_S_CURVE_CYCLES 0UL + #endif + + // Stepper Loop base cycles + #define ISR_LOOP_BASE_CYCLES 4UL + + // To start the step pulse, in the worst case takes + #define ISR_START_STEPPER_CYCLES 13UL + + // And each stepper (start + stop pulse) takes in worst case + #define ISR_STEPPER_CYCLES 16UL + +#else + // Cycles to perform actions in START_TIMED_PULSE + #define TIMER_READ_ADD_AND_STORE_CYCLES 13UL + + // The base ISR takes 752 cycles + #define ISR_BASE_CYCLES 752UL + + // Linear advance base time is 32 cycles + #if ENABLED(LIN_ADVANCE) + #define ISR_LA_BASE_CYCLES 32UL + #else + #define ISR_LA_BASE_CYCLES 0UL + #endif + + // S curve interpolation adds 160 cycles + #if ENABLED(S_CURVE_ACCELERATION) + #define ISR_S_CURVE_CYCLES 160UL + #else + #define ISR_S_CURVE_CYCLES 0UL + #endif + + // Stepper Loop base cycles + #define ISR_LOOP_BASE_CYCLES 32UL + + // To start the step pulse, in the worst case takes + #define ISR_START_STEPPER_CYCLES 57UL + + // And each stepper (start + stop pulse) takes in worst case + #define ISR_STEPPER_CYCLES 88UL + +#endif + +// Add time for each stepper +#if HAS_X_STEP + #define ISR_X_STEPPER_CYCLES ISR_STEPPER_CYCLES +#else + #define ISR_X_STEPPER_CYCLES 0UL +#endif +#if HAS_Y_STEP + #define ISR_Y_STEPPER_CYCLES ISR_STEPPER_CYCLES +#else + #define ISR_START_Y_STEPPER_CYCLES 0UL + #define ISR_Y_STEPPER_CYCLES 0UL +#endif +#if HAS_Z_STEP + #define ISR_Z_STEPPER_CYCLES ISR_STEPPER_CYCLES +#else + #define ISR_Z_STEPPER_CYCLES 0UL +#endif + +// E is always interpolated, even for mixing extruders +#define ISR_E_STEPPER_CYCLES ISR_STEPPER_CYCLES + +// If linear advance is disabled, the loop also handles them +#if DISABLED(LIN_ADVANCE) && ENABLED(MIXING_EXTRUDER) + #define ISR_MIXING_STEPPER_CYCLES ((MIXING_STEPPERS) * (ISR_STEPPER_CYCLES)) +#else + #define ISR_MIXING_STEPPER_CYCLES 0UL +#endif + +// 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) + +// Calculate the minimum MPU cycles needed per pulse to enforce, limited to the max stepper rate +#define _MIN_STEPPER_PULSE_CYCLES(N) _MAX(uint32_t((F_CPU) / (MAXIMUM_STEPPER_RATE)), ((F_CPU) / 500000UL) * (N)) +#if MINIMUM_STEPPER_PULSE + #define MIN_STEPPER_PULSE_CYCLES _MIN_STEPPER_PULSE_CYCLES(uint32_t(MINIMUM_STEPPER_PULSE)) +#elif HAS_DRIVER(LV8729) + #define MIN_STEPPER_PULSE_CYCLES uint32_t((((F_CPU) - 1) / 2000000) + 1) // 0.5µs, aka 500ns +#else + #define MIN_STEPPER_PULSE_CYCLES _MIN_STEPPER_PULSE_CYCLES(1UL) +#endif + +// Calculate the minimum pulse times (high and low) +#if MINIMUM_STEPPER_PULSE && MAXIMUM_STEPPER_RATE + 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_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 + #error "Expected at least one of MINIMUM_STEPPER_PULSE or MAXIMUM_STEPPER_RATE to be defined" +#endif + +// 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)) + +// If linear advance is enabled, then it is handled separately +#if ENABLED(LIN_ADVANCE) + + // Estimate the minimum LA loop time + #if ENABLED(MIXING_EXTRUDER) // ToDo: ??? + // HELP ME: What is what? + // Directions are set up for MIXING_STEPPERS - like before. + // Finding the right stepper may last up to MIXING_STEPPERS loops in get_next_stepper(). + // These loops are a bit faster than advancing a bresenham counter. + // Always only one e-stepper is stepped. + #define MIN_ISR_LA_LOOP_CYCLES ((MIXING_STEPPERS) * (ISR_STEPPER_CYCLES)) + #else + #define MIN_ISR_LA_LOOP_CYCLES ISR_STEPPER_CYCLES + #endif + + // And the real loop time + #define ISR_LA_LOOP_CYCLES _MAX(MIN_STEPPER_PULSE_CYCLES, MIN_ISR_LA_LOOP_CYCLES) + +#else + #define ISR_LA_LOOP_CYCLES 0UL +#endif + +// Now estimate the total ISR execution time in cycles given a step per ISR multiplier +#define ISR_EXECUTION_CYCLES(R) (((ISR_BASE_CYCLES + ISR_S_CURVE_CYCLES + (ISR_LOOP_CYCLES) * (R) + ISR_LA_BASE_CYCLES + ISR_LA_LOOP_CYCLES)) / (R)) + +// The maximum allowable stepping frequency when doing x128-x1 stepping (in Hz) +#define MAX_STEP_ISR_FREQUENCY_128X ((F_CPU) / ISR_EXECUTION_CYCLES(128)) +#define MAX_STEP_ISR_FREQUENCY_64X ((F_CPU) / ISR_EXECUTION_CYCLES(64)) +#define MAX_STEP_ISR_FREQUENCY_32X ((F_CPU) / ISR_EXECUTION_CYCLES(32)) +#define MAX_STEP_ISR_FREQUENCY_16X ((F_CPU) / ISR_EXECUTION_CYCLES(16)) +#define MAX_STEP_ISR_FREQUENCY_8X ((F_CPU) / ISR_EXECUTION_CYCLES(8)) +#define MAX_STEP_ISR_FREQUENCY_4X ((F_CPU) / ISR_EXECUTION_CYCLES(4)) +#define MAX_STEP_ISR_FREQUENCY_2X ((F_CPU) / ISR_EXECUTION_CYCLES(2)) +#define MAX_STEP_ISR_FREQUENCY_1X ((F_CPU) / ISR_EXECUTION_CYCLES(1)) + +// The minimum step ISR rate used by ADAPTIVE_STEP_SMOOTHING to target 50% CPU usage +// This does not account for the possibility of multi-stepping. +// Perhaps DISABLE_MULTI_STEPPING should be required with ADAPTIVE_STEP_SMOOTHING. +#define MIN_STEP_ISR_FREQUENCY (MAX_STEP_ISR_FREQUENCY_1X / 2) + +// +// Stepper class definition +// +class Stepper { + + public: + + #if EITHER(HAS_EXTRA_ENDSTOPS, Z_STEPPER_AUTO_ALIGN) + static bool separate_multi_axis; + #endif + + #if HAS_MOTOR_CURRENT_SPI || HAS_MOTOR_CURRENT_PWM + #if HAS_MOTOR_CURRENT_PWM + #ifndef PWM_MOTOR_CURRENT + #define PWM_MOTOR_CURRENT DEFAULT_PWM_MOTOR_CURRENT + #endif + #define MOTOR_CURRENT_COUNT 3 + #elif HAS_MOTOR_CURRENT_SPI + static constexpr uint32_t digipot_count[] = DIGIPOT_MOTOR_CURRENT; + #define MOTOR_CURRENT_COUNT COUNT(Stepper::digipot_count) + #endif + static bool initialized; + static uint32_t motor_current_setting[MOTOR_CURRENT_COUNT]; // Initialized by settings.load() + #endif + + // Last-moved extruder, as set when the last movement was fetched from planner + #if HAS_MULTI_EXTRUDER + static uint8_t last_moved_extruder; + #else + static constexpr uint8_t last_moved_extruder = 0; + #endif + + private: + + static block_t* current_block; // A pointer to the block currently being traced + + static uint8_t last_direction_bits, // The next stepping-bits to be output + axis_did_move; // Last Movement in the given direction is not null, as computed when the last movement was fetched from planner + + static bool abort_current_block; // Signals to the stepper that current block should be aborted + + #if ENABLED(X_DUAL_ENDSTOPS) + static bool locked_X_motor, locked_X2_motor; + #endif + #if ENABLED(Y_DUAL_ENDSTOPS) + static bool locked_Y_motor, locked_Y2_motor; + #endif + #if EITHER(Z_MULTI_ENDSTOPS, Z_STEPPER_AUTO_ALIGN) + static bool locked_Z_motor, locked_Z2_motor + #if NUM_Z_STEPPER_DRIVERS >= 3 + , locked_Z3_motor + #if NUM_Z_STEPPER_DRIVERS >= 4 + , locked_Z4_motor + #endif + #endif + ; + #endif + + static uint32_t acceleration_time, deceleration_time; // time measured in Stepper Timer ticks + static uint8_t steps_per_isr; // Count of steps to perform per Stepper ISR call + + #if ENABLED(ADAPTIVE_STEP_SMOOTHING) + static uint8_t oversampling_factor; // Oversampling factor (log2(multiplier)) to increase temporal resolution of axis + #else + static constexpr uint8_t oversampling_factor = 0; + #endif + + // Delta error variables for the Bresenham line tracer + static xyze_long_t delta_error; + static xyze_ulong_t advance_dividend; + static uint32_t advance_divisor, + step_events_completed, // The number of step events executed in the current block + accelerate_until, // The point from where we need to stop acceleration + decelerate_after, // The point from where we need to start decelerating + step_event_count; // The total event count for the current block + + #if EITHER(HAS_MULTI_EXTRUDER, MIXING_EXTRUDER) + static uint8_t stepper_extruder; + #else + static constexpr uint8_t stepper_extruder = 0; + #endif + + #if ENABLED(S_CURVE_ACCELERATION) + static int32_t bezier_A, // A coefficient in Bézier speed curve + bezier_B, // B coefficient in Bézier speed curve + bezier_C; // C coefficient in Bézier speed curve + static uint32_t bezier_F, // F coefficient in Bézier speed curve + bezier_AV; // AV coefficient in Bézier speed curve + #ifdef __AVR__ + static bool A_negative; // If A coefficient was negative + #endif + static bool bezier_2nd_half; // If Bézier curve has been initialized or not + #endif + + #if ENABLED(LIN_ADVANCE) + static constexpr uint32_t LA_ADV_NEVER = 0xFFFFFFFF; + static uint32_t nextAdvanceISR, LA_isr_rate; + static uint16_t LA_current_adv_steps, LA_final_adv_steps, LA_max_adv_steps; // Copy from current executed block. Needed because current_block is set to NULL "too early". + static int8_t LA_steps; + static bool LA_use_advance_lead; + #endif + + #if ENABLED(INTEGRATED_BABYSTEPPING) + static constexpr uint32_t BABYSTEP_NEVER = 0xFFFFFFFF; + static uint32_t nextBabystepISR; + #endif + + #if ENABLED(DIRECT_STEPPING) + static page_step_state_t page_step_state; + #endif + + static int32_t ticks_nominal; + #if DISABLED(S_CURVE_ACCELERATION) + static uint32_t acc_step_rate; // needed for deceleration start point + #endif + + // Exact steps at which an endstop was triggered + static xyz_long_t endstops_trigsteps; + + // Positions of stepper motors, in step units + static xyze_long_t count_position; + + // Current stepper motor directions (+1 or -1) + static xyze_int8_t count_direction; + + #if ENABLED(LASER_POWER_INLINE_TRAPEZOID) + + typedef struct { + bool enabled; // Trapezoid needed flag (i.e., laser on, planner in control) + uint8_t cur_power; // Current laser power + bool cruise_set; // Power set up for cruising? + + #if DISABLED(LASER_POWER_INLINE_TRAPEZOID_CONT) + uint32_t last_step_count, // Step count from the last update + acc_step_count; // Bresenham counter for laser accel/decel + #else + uint16_t till_update; // Countdown to the next update + #endif + } stepper_laser_t; + + static stepper_laser_t laser_trap; + + #endif + + public: + // Initialize stepper hardware + static void init(); + + // Interrupt Service Routine and phases + + // The stepper subsystem goes to sleep when it runs out of things to execute. + // Call this to notify the subsystem that it is time to go to work. + static inline void wake_up() { ENABLE_STEPPER_DRIVER_INTERRUPT(); } + + static inline bool is_awake() { return STEPPER_ISR_ENABLED(); } + + static inline bool suspend() { + const bool awake = is_awake(); + if (awake) DISABLE_STEPPER_DRIVER_INTERRUPT(); + return awake; + } + + // The ISR scheduler + static void isr(); + + // The stepper pulse ISR phase + static void pulse_phase_isr(); + + // The stepper block processing ISR phase + static uint32_t block_phase_isr(); + + #if ENABLED(LIN_ADVANCE) + // The Linear advance ISR phase + static uint32_t advance_isr(); + FORCE_INLINE static void initiateLA() { nextAdvanceISR = 0; } + #endif + + #if ENABLED(INTEGRATED_BABYSTEPPING) + // The Babystepping ISR phase + static uint32_t babystepping_isr(); + FORCE_INLINE static void initiateBabystepping() { + if (nextBabystepISR == BABYSTEP_NEVER) { + nextBabystepISR = 0; + wake_up(); + } + } + #endif + + // Check if the given block is busy or not - Must not be called from ISR contexts + static bool is_block_busy(const block_t* const block); + + // Get the position of a stepper, in steps + static int32_t position(const AxisEnum axis); + + // Set the current position in steps + static void set_position(const int32_t &a, const int32_t &b, const int32_t &c, const int32_t &e); + static inline void set_position(const xyze_long_t &abce) { set_position(abce.a, abce.b, abce.c, abce.e); } + static void set_axis_position(const AxisEnum a, const int32_t &v); + + // Report the positions of the steppers, in steps + static void report_a_position(const xyz_long_t &pos); + static void report_positions(); + + // Discard current block and free any resources + FORCE_INLINE static void discard_current_block() { + #if ENABLED(DIRECT_STEPPING) + if (IS_PAGE(current_block)) + page_manager.free_page(current_block->page_idx); + #endif + current_block = nullptr; + axis_did_move = 0; + planner.release_current_block(); + } + + // Quickly stop all steppers + FORCE_INLINE static void quick_stop() { abort_current_block = true; } + + // The direction of a single motor + FORCE_INLINE static bool motor_direction(const AxisEnum axis) { return TEST(last_direction_bits, axis); } + + // The last movement direction was not null on the specified axis. Note that motor direction is not necessarily the same. + FORCE_INLINE static bool axis_is_moving(const AxisEnum axis) { return TEST(axis_did_move, axis); } + + // Handle a triggered endstop + static void endstop_triggered(const AxisEnum axis); + + // Triggered position of an axis in steps + static int32_t triggered_position(const AxisEnum axis); + + #if HAS_MOTOR_CURRENT_SPI || HAS_MOTOR_CURRENT_PWM + static void set_digipot_value_spi(const int16_t address, const int16_t value); + static void set_digipot_current(const uint8_t driver, const int16_t current); + #endif + + #if HAS_MICROSTEPS + static void microstep_ms(const uint8_t driver, const int8_t ms1, const int8_t ms2, const int8_t ms3); + static void microstep_mode(const uint8_t driver, const uint8_t stepping); + static void microstep_readings(); + #endif + + #if EITHER(HAS_EXTRA_ENDSTOPS, Z_STEPPER_AUTO_ALIGN) + FORCE_INLINE static void set_separate_multi_axis(const bool state) { separate_multi_axis = state; } + #endif + #if ENABLED(X_DUAL_ENDSTOPS) + FORCE_INLINE static void set_x_lock(const bool state) { locked_X_motor = state; } + FORCE_INLINE static void set_x2_lock(const bool state) { locked_X2_motor = state; } + #endif + #if ENABLED(Y_DUAL_ENDSTOPS) + FORCE_INLINE static void set_y_lock(const bool state) { locked_Y_motor = state; } + FORCE_INLINE static void set_y2_lock(const bool state) { locked_Y2_motor = state; } + #endif + #if EITHER(Z_MULTI_ENDSTOPS, Z_STEPPER_AUTO_ALIGN) + FORCE_INLINE static void set_z1_lock(const bool state) { locked_Z_motor = state; } + FORCE_INLINE static void set_z2_lock(const bool state) { locked_Z2_motor = state; } + #if NUM_Z_STEPPER_DRIVERS >= 3 + FORCE_INLINE static void set_z3_lock(const bool state) { locked_Z3_motor = state; } + #if NUM_Z_STEPPER_DRIVERS >= 4 + FORCE_INLINE static void set_z4_lock(const bool state) { locked_Z4_motor = state; } + #endif + #endif + static inline void set_all_z_lock(const bool lock, const int8_t except=-1) { + set_z1_lock(lock ^ (except == 0)); + set_z2_lock(lock ^ (except == 1)); + #if NUM_Z_STEPPER_DRIVERS >= 3 + set_z3_lock(lock ^ (except == 2)); + #if NUM_Z_STEPPER_DRIVERS >= 4 + set_z4_lock(lock ^ (except == 3)); + #endif + #endif + } + #endif + + #if ENABLED(BABYSTEPPING) + static void do_babystep(const AxisEnum axis, const bool direction); // perform a short step with a single stepper motor, outside of any convention + #endif + + #if HAS_MOTOR_CURRENT_PWM + static void refresh_motor_power(); + #endif + + // Update direction states for all steppers + static void set_directions(); + + // Set direction bits and update all stepper DIR states + static void set_directions(const uint8_t bits) { + last_direction_bits = bits; + set_directions(); + } + + private: + + // Set the current position in steps + static void _set_position(const int32_t &a, const int32_t &b, const int32_t &c, const int32_t &e); + FORCE_INLINE static void _set_position(const abce_long_t &spos) { _set_position(spos.a, spos.b, spos.c, spos.e); } + + FORCE_INLINE static uint32_t calc_timer_interval(uint32_t step_rate, uint8_t* loops) { + uint32_t timer; + + // Scale the frequency, as requested by the caller + step_rate <<= oversampling_factor; + + uint8_t multistep = 1; + #if DISABLED(DISABLE_MULTI_STEPPING) + + // The stepping frequency limits for each multistepping rate + static const uint32_t limit[] PROGMEM = { + ( MAX_STEP_ISR_FREQUENCY_1X ), + ( MAX_STEP_ISR_FREQUENCY_2X >> 1), + ( MAX_STEP_ISR_FREQUENCY_4X >> 2), + ( MAX_STEP_ISR_FREQUENCY_8X >> 3), + ( MAX_STEP_ISR_FREQUENCY_16X >> 4), + ( MAX_STEP_ISR_FREQUENCY_32X >> 5), + ( MAX_STEP_ISR_FREQUENCY_64X >> 6), + (MAX_STEP_ISR_FREQUENCY_128X >> 7) + }; + + // Select the proper multistepping + uint8_t idx = 0; + while (idx < 7 && step_rate > (uint32_t)pgm_read_dword(&limit[idx])) { + step_rate >>= 1; + multistep <<= 1; + ++idx; + }; + #else + NOMORE(step_rate, uint32_t(MAX_STEP_ISR_FREQUENCY_1X)); + #endif + *loops = multistep; + + #ifdef CPU_32_BIT + // In case of high-performance processor, it is able to calculate in real-time + timer = uint32_t(STEPPER_TIMER_RATE) / step_rate; + #else + constexpr uint32_t min_step_rate = (F_CPU) / 500000U; + NOLESS(step_rate, min_step_rate); + step_rate -= min_step_rate; // Correct for minimal speed + if (step_rate >= (8 * 256)) { // higher step rate + const uint8_t tmp_step_rate = (step_rate & 0x00FF); + const uint16_t table_address = (uint16_t)&speed_lookuptable_fast[(uint8_t)(step_rate >> 8)][0], + gain = (uint16_t)pgm_read_word(table_address + 2); + timer = MultiU16X8toH16(tmp_step_rate, gain); + timer = (uint16_t)pgm_read_word(table_address) - timer; + } + else { // lower step rates + uint16_t table_address = (uint16_t)&speed_lookuptable_slow[0][0]; + table_address += ((step_rate) >> 1) & 0xFFFC; + timer = (uint16_t)pgm_read_word(table_address) + - (((uint16_t)pgm_read_word(table_address + 2) * (uint8_t)(step_rate & 0x0007)) >> 3); + } + // (there is no need to limit the timer value here. All limits have been + // applied above, and AVR is able to keep up at 30khz Stepping ISR rate) + #endif + + return timer; + } + + #if ENABLED(S_CURVE_ACCELERATION) + static void _calc_bezier_curve_coeffs(const int32_t v0, const int32_t v1, const uint32_t av); + static int32_t _eval_bezier_curve(const uint32_t curr_step); + #endif + + #if HAS_MOTOR_CURRENT_SPI || HAS_MOTOR_CURRENT_PWM + static void digipot_init(); + #endif + + #if HAS_MICROSTEPS + static void microstep_init(); + #endif + +}; + +extern Stepper stepper; |