From ece1f71c645da7115f497642c16278417a1f5292 Mon Sep 17 00:00:00 2001 From: Kevin O'Connor Date: Sun, 1 Oct 2017 16:31:05 -0400 Subject: [PATCH] endstop: Support oversampling of the endstop Some printers can show occasional noise on the endstop pin. Support sampling the endstop pin multiple times to attempt to filter out this noise. Signed-off-by: Kevin O'Connor --- klippy/mcu.py | 9 +++++++++ klippy/stepper.py | 5 +++++ src/endstop.c | 50 ++++++++++++++++++++++++++++++++++++++++++----- 3 files changed, 59 insertions(+), 5 deletions(-) diff --git a/klippy/mcu.py b/klippy/mcu.py index a2f742cc..a24a3ba3 100644 --- a/klippy/mcu.py +++ b/klippy/mcu.py @@ -137,6 +137,8 @@ class MCU_endstop: self._pin = pin_params['pin'] self._pullup = pin_params['pullup'] self._invert = pin_params['invert'] + self._oversample_count = 0 + self._oversample_time = 0. self._cmd_queue = mcu.alloc_command_queue() self._oid = self._home_cmd = self._query_cmd = None self._homing = False @@ -144,6 +146,9 @@ class MCU_endstop: self._last_state = {} def get_mcu(self): return self._mcu + def setup_oversample(self, oversample_count, oversample_time): + self._oversample_count = oversample_count + self._oversample_time = oversample_time def add_stepper(self, stepper): self._steppers.append(stepper) def build_config(self): @@ -155,6 +160,10 @@ class MCU_endstop: self._mcu.add_config_cmd( "end_stop_set_stepper oid=%d pos=%d stepper_oid=%d" % ( self._oid, i, s.get_oid()), is_init=True) + self._mcu.add_config_cmd( + "end_stop_set_oversample oid=%d sample_ticks=%d sample_count=%d" % ( + self._oid, self._mcu.seconds_to_clock(self._oversample_time), + self._oversample_count), is_init=True) self._home_cmd = self._mcu.lookup_command( "end_stop_home oid=%c clock=%u rest_ticks=%u pin_value=%c") self._query_cmd = self._mcu.lookup_command("end_stop_query oid=%c") diff --git a/klippy/stepper.py b/klippy/stepper.py index ab1af2ba..5040ce9e 100644 --- a/klippy/stepper.py +++ b/klippy/stepper.py @@ -6,6 +6,9 @@ import math, logging import homing, pins +ENDSTOP_OVERSAMPLE_COUNT = 4 +ENDSTOP_OVERSAMPLE_TIME = .000015 + class PrinterStepper: def __init__(self, printer, config, name): self.name = name @@ -52,6 +55,8 @@ class PrinterHomingStepper(PrinterStepper): self.mcu_endstop = pins.setup_pin( printer, 'endstop', config.get('endstop_pin')) + self.mcu_endstop.setup_oversample( + ENDSTOP_OVERSAMPLE_COUNT, ENDSTOP_OVERSAMPLE_TIME) self.mcu_endstop.add_stepper(self.mcu_stepper) self.position_min = config.getfloat('position_min', 0.) self.position_max = config.getfloat( diff --git a/src/endstop.c b/src/endstop.c index 5bd863ea..67110f46 100644 --- a/src/endstop.c +++ b/src/endstop.c @@ -13,9 +13,9 @@ struct end_stop { struct timer time; - uint32_t rest_time; + uint32_t rest_time, sample_time; struct gpio_in pin; - uint8_t flags, stepper_count; + uint8_t flags, stepper_count, sample_count, trigger_count; struct stepper *steppers[0]; }; @@ -34,6 +34,8 @@ stop_steppers(struct end_stop *e) sched_wake_task(&endstop_wake); } +static uint_fast8_t end_stop_oversample_event(struct timer *t); + // Timer callback for an end stop static uint_fast8_t end_stop_event(struct timer *t) @@ -45,8 +47,32 @@ end_stop_event(struct timer *t) e->time.waketime += e->rest_time; return SF_RESCHEDULE; } - stop_steppers(e); - return SF_DONE; + e->time.func = end_stop_oversample_event; + return end_stop_oversample_event(t); +} + +// Timer callback for an end stop this is sampling extra times +static uint_fast8_t +end_stop_oversample_event(struct timer *t) +{ + struct end_stop *e = container_of(t, struct end_stop, time); + uint8_t val = gpio_in_read(e->pin); + if ((val ? ~e->flags : e->flags) & ESF_PIN_HIGH) { + // No longer matching - reschedule for the next attempt + e->time.func = end_stop_event; + uint8_t past_triggers = e->sample_count - e->trigger_count; + e->time.waketime += e->rest_time - past_triggers * e->sample_time; + e->trigger_count = e->sample_count; + return SF_RESCHEDULE; + } + uint8_t count = e->trigger_count - 1; + if (!count) { + stop_steppers(e); + return SF_DONE; + } + e->trigger_count = count; + e->time.waketime += e->sample_time; + return SF_RESCHEDULE; } void @@ -56,9 +82,9 @@ command_config_end_stop(uint32_t *args) struct end_stop *e = oid_alloc( args[0], command_config_end_stop , sizeof(*e) + sizeof(e->steppers[0]) * stepper_count); - e->time.func = end_stop_event; e->pin = gpio_in_setup(args[1], args[2]); e->stepper_count = stepper_count; + e->sample_count = 1; } DECL_COMMAND(command_config_end_stop, "config_end_stop oid=%c pin=%c pull_up=%c stepper_count=%c"); @@ -75,6 +101,18 @@ command_end_stop_set_stepper(uint32_t *args) DECL_COMMAND(command_end_stop_set_stepper, "end_stop_set_stepper oid=%c pos=%c stepper_oid=%c"); +void +command_end_stop_set_oversample(uint32_t *args) +{ + struct end_stop *e = oid_lookup(args[0], command_config_end_stop); + e->sample_time = args[1]; + e->sample_count = args[2]; + if (!e->sample_count) + e->sample_count = 1; +} +DECL_COMMAND(command_end_stop_set_oversample, + "end_stop_set_oversample oid=%c sample_ticks=%u sample_count=%c"); + // Home an axis void command_end_stop_home(uint32_t *args) @@ -88,6 +126,8 @@ command_end_stop_home(uint32_t *args) e->flags = 0; return; } + e->time.func = end_stop_event; + e->trigger_count = e->sample_count; e->flags = ESF_HOMING | (args[3] ? ESF_PIN_HIGH : 0); sched_add_timer(&e->time); }