diff options
| -rw-r--r-- | src/Kconfig | 7 | ||||
| -rw-r--r-- | src/avr/Kconfig | 1 | ||||
| -rw-r--r-- | src/stepper.c | 91 |
3 files changed, 80 insertions, 19 deletions
diff --git a/src/Kconfig b/src/Kconfig index db265c96..1a326d06 100644 --- a/src/Kconfig +++ b/src/Kconfig @@ -25,6 +25,13 @@ config HAVE_GPIO_HARD_PWM bool default n +config NO_UNSTEP_DELAY + # Slow micro-controllers do not require a delay before returning a + # stepper step pin to its default level. A board can enable this + # option to optimize the stepper_event() handler in this case. + bool + default n + config INLINE_STEPPER_HACK # Enables gcc to inline stepper_event() into the main timer irq handler bool diff --git a/src/avr/Kconfig b/src/avr/Kconfig index 8d5d4522..f678d639 100644 --- a/src/avr/Kconfig +++ b/src/avr/Kconfig @@ -8,6 +8,7 @@ config AVR_SELECT select HAVE_GPIO_ADC select HAVE_GPIO_SPI select HAVE_GPIO_HARD_PWM + select NO_UNSTEP_DELAY config BOARD_DIRECTORY string diff --git a/src/stepper.c b/src/stepper.c index 5b5203f1..7b794d50 100644 --- a/src/stepper.c +++ b/src/stepper.c @@ -22,7 +22,13 @@ struct stepper { struct timer time; uint32_t interval; int16_t add; +#if CONFIG_NO_UNSTEP_DELAY uint16_t count; +#define next_step_time time.waketime +#else + uint32_t count; + uint32_t next_step_time; +#endif struct gpio_out step_pin, dir_pin; uint32_t position; struct move *first, **plast; @@ -36,7 +42,7 @@ enum { SF_LAST_DIR=1, SF_NEXT_DIR=2, SF_INVERT_STEP=4, SF_HAVE_ADD=8 }; // Setup a stepper for the next move in its queue static uint_fast8_t -stepper_load_next(struct stepper *s) +stepper_load_next(struct stepper *s, uint32_t min_next_time) { struct move *m = s->first; if (!m) { @@ -46,16 +52,32 @@ stepper_load_next(struct stepper *s) return SF_DONE; } - s->time.waketime += m->interval; + s->next_step_time += m->interval; s->add = m->add; s->interval = m->interval + m->add; - s->flags = m->add ? s->flags | SF_HAVE_ADD : s->flags & ~SF_HAVE_ADD; - s->count = m->count; + if (CONFIG_NO_UNSTEP_DELAY) { + // On slow mcus see if the add can be optimized away + s->flags = m->add ? s->flags | SF_HAVE_ADD : s->flags & ~SF_HAVE_ADD; + s->count = m->count; + } else { + // On faster mcus, it is necessary to schedule unstep events + // and so there are twice as many events. Also check that the + // next step event isn't too close to the last unstep. + if (unlikely(sched_is_before(s->next_step_time, min_next_time))) { + if ((int32_t)(s->next_step_time - min_next_time) + < (int32_t)(-sched_from_us(1000))) + shutdown("stepper too far in past"); + s->time.waketime = min_next_time; + } else { + s->time.waketime = s->next_step_time; + } + s->count = m->count * 2; + } if (m->flags & MF_DIR) { - s->position = -s->position + s->count; + s->position = -s->position + m->count; gpio_out_toggle(s->dir_pin); } else { - s->position += s->count; + s->position += m->count; } s->first = m->next; @@ -63,24 +85,51 @@ stepper_load_next(struct stepper *s) return SF_RESCHEDULE; } +#define UNSTEP_TIME sched_from_us(1) + // Timer callback - step the given stepper. uint_fast8_t stepper_event(struct timer *t) { struct stepper *s = container_of(t, struct stepper, time); - gpio_out_toggle(s->step_pin); - uint16_t count = s->count - 1; - if (likely(count)) { - s->count = count; - s->time.waketime += s->interval; + if (CONFIG_NO_UNSTEP_DELAY) { + // On slower mcus it is possible to simply step and unstep in + // the same timer event. gpio_out_toggle(s->step_pin); - if (s->flags & SF_HAVE_ADD) - s->interval += s->add; - return SF_RESCHEDULE; + uint16_t count = s->count - 1; + if (likely(count)) { + s->count = count; + s->time.waketime += s->interval; + gpio_out_toggle(s->step_pin); + if (s->flags & SF_HAVE_ADD) + s->interval += s->add; + return SF_RESCHEDULE; + } + uint_fast8_t ret = stepper_load_next(s, 0); + gpio_out_toggle(s->step_pin); + return ret; } - uint_fast8_t ret = stepper_load_next(s); + + // On faster mcus, it is necessary to schedule the unstep event + uint32_t min_next_time = sched_read_time() + UNSTEP_TIME; gpio_out_toggle(s->step_pin); - return ret; + s->count--; + if (likely(s->count & 1)) + // Schedule unstep event + goto reschedule_min; + if (likely(s->count)) { + s->next_step_time += s->interval; + s->interval += s->add; + if (unlikely(sched_is_before(s->next_step_time, min_next_time))) + // The next step event is too close - push it back + goto reschedule_min; + s->time.waketime = s->next_step_time; + return SF_RESCHEDULE; + } + return stepper_load_next(s, min_next_time); +reschedule_min: + s->time.waketime = min_next_time; + return SF_RESCHEDULE; } void @@ -126,7 +175,7 @@ command_queue_step(uint32_t *args) s->plast = &m->next; } else { s->first = m; - stepper_load_next(s); + stepper_load_next(s, s->next_step_time + m->interval); sched_timer(&s->time); } irq_enable(); @@ -154,7 +203,7 @@ command_reset_step_clock(uint32_t *args) uint32_t waketime = args[1]; if (s->count) shutdown("Can't reset time when stepper active"); - s->time.waketime = waketime; + s->next_step_time = waketime; } DECL_COMMAND(command_reset_step_clock, "reset_step_clock oid=%c clock=%u"); @@ -162,7 +211,11 @@ DECL_COMMAND(command_reset_step_clock, "reset_step_clock oid=%c clock=%u"); uint32_t stepper_get_position(struct stepper *s) { - uint32_t position = s->position - s->count; + uint32_t position = s->position; + if (CONFIG_NO_UNSTEP_DELAY) + position -= s->count; + else + position -= s->count / 2; if (position & 0x80000000) return -position; return position; |