pwm_cycle_time: New module for output pins with dynamic cycle times

Remove support for changing the cycle time of pwm pins from the
output_pin module.  Use a new pwm_cycle_time module that supports
setting dynamic cycle times.  This simplifies the output_pin code and
low-level pin update code.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

config/sample-macros.cfg

@@ -61,12 +61,10 @@ gcode:
 #   P is the tone duration, S the tone frequency.
 # The frequency won't be pitch perfect.
 
-[output_pin BEEPER_pin]
+[pwm_cycle_time BEEPER_pin]
 pin: ar37
 #   Beeper pin. This parameter must be provided.
 #   ar37 is the default RAMPS/MKS pin.
-pwm: True
-#   A piezo beeper needs a PWM signal, a DC buzzer doesn't.
 value: 0
 #   Silent at power on, set to 1 if active low.
 shutdown_value: 0

docs/Config_Changes.md

@@ -8,6 +8,11 @@ All dates in this document are approximate.
 
 ## Changes
 
+20240123: The output_pin SET_PIN CYCLE_TIME parameter has been
+removed. Use the new
+[pwm_cycle_time](Config_Reference.md#pwm_cycle_time) module if it is
+necessary to dynamically change a pwm pin's cycle time.
+
 20240123: The output_pin `maximum_mcu_duration` parameter is
 deprecated. Use a [pwm_tool config section](Config_Reference.md#pwm_tool)
 instead. The option will be removed in the near future.

docs/Config_Reference.md

@@ -3153,6 +3153,24 @@ pin:
 #   See the "output_pin" section for the definition of these parameters.
 ```
 
+### [pwm_cycle_time]
+
+Run-time configurable output pins with dynamic pwm cycle timing (one
+may define any number of sections with an "pwm_cycle_time" prefix).
+Pins configured here will be setup as output pins and one may modify
+them at run-time using "SET_PIN PIN=my_pin VALUE=.1 CYCLE_TIME=0.100"
+type extended [g-code commands](G-Codes.md#pwm_cycle_time).
+
+```
+[pwm_cycle_time my_pin]
+pin:
+#value:
+#shutdown_value:
+#cycle_time: 0.100
+#scale:
+#   See the "output_pin" section for information on these parameters.
+```
+
 ### [static_digital_output]
 
 Statically configured digital output pins (one may define any number

docs/G-Codes.md

@@ -839,17 +839,10 @@ The following command is available when an
 enabled.
 
 #### SET_PIN
-`SET_PIN PIN=config_name VALUE=<value> [CYCLE_TIME=<cycle_time>]`: Set
+`SET_PIN PIN=config_name VALUE=<value>`: Set the pin to the given
-the pin to the given output `VALUE`. VALUE should be 0 or 1 for
+output `VALUE`. VALUE should be 0 or 1 for "digital" output pins. For
-"digital" output pins. For PWM pins, set to a value between 0.0 and
+PWM pins, set to a value between 0.0 and 1.0, or between 0.0 and
-1.0, or between 0.0 and `scale` if a scale is configured in the
+`scale` if a scale is configured in the output_pin config section.
-output_pin config section.
-
-Some pins (currently only "soft PWM" pins) support setting an explicit
-cycle time using the CYCLE_TIME parameter (specified in seconds). Note
-that the CYCLE_TIME parameter is not stored between SET_PIN commands
-(any SET_PIN command without an explicit CYCLE_TIME parameter will use
-the `cycle_time` specified in the output_pin config section).
 
 ### [palette2]
 
@@ -978,6 +971,21 @@ babystepping), and subtract if from the probe's z_offset.  This acts
 to take a frequently used babystepping value, and "make it permanent".
 Requires a `SAVE_CONFIG` to take effect.
 
+### [pwm_cycle_time]
+
+The following command is available when a
+[pwm_cycle_time config section](Config_Reference.md#pwm_cycle_time)
+is enabled.
+
+#### SET_PIN
+`SET_PIN PIN=config_name VALUE=<value> [CYCLE_TIME=<cycle_time>]`:
+This command works similarly to [output_pin](#output_pin) SET_PIN
+commands. The command here supports setting an explicit cycle time
+using the CYCLE_TIME parameter (specified in seconds). Note that the
+CYCLE_TIME parameter is not stored between SET_PIN commands (any
+SET_PIN command without an explicit CYCLE_TIME parameter will use the
+`cycle_time` specified in the pwm_cycle_time config section).
+
 ### [query_adc]
 
 The query_adc module is automatically loaded.

docs/Status_Reference.md

@@ -374,6 +374,13 @@ is defined):
   template expansion, the PROBE (or similar) command must be run prior
   to the macro containing this reference.
 
+## pwm_cycle_time
+
+The following information is available in
+[pwm_cycle_time some_name](Config_Reference.md#pwm_cycle_time)
+objects:
+- `value`: The "value" of the pin, as set by a `SET_PIN` command.
+
 ## quad_gantry_level
 
 The following information is available in the `quad_gantry_level` object

klippy/extras/output_pin.py

@@ -1,6 +1,6 @@
-# Code to configure miscellaneous chips
+# PWM and digital output pin handling
 #
-# Copyright (C) 2017-2021  Kevin O'Connor <kevin@koconnor.net>
+# Copyright (C) 2017-2024  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 
@@ -21,11 +21,9 @@ class PrinterOutputPin:
             hardware_pwm = config.getboolean('hardware_pwm', False)
             self.mcu_pin.setup_cycle_time(cycle_time, hardware_pwm)
             self.scale = config.getfloat('scale', 1., above=0.)
-            self.last_cycle_time = self.default_cycle_time = cycle_time
         else:
             self.mcu_pin = ppins.setup_pin('digital_out', config.get('pin'))
             self.scale = 1.
-            self.last_cycle_time = self.default_cycle_time = 0.
         self.last_print_time = 0.
         # Support mcu checking for maximum duration
         self.reactor = self.printer.get_reactor()
@@ -58,32 +56,30 @@ class PrinterOutputPin:
                                    desc=self.cmd_SET_PIN_help)
     def get_status(self, eventtime):
         return {'value': self.last_value}
-    def _set_pin(self, print_time, value, cycle_time, is_resend=False):
+    def _set_pin(self, print_time, value, is_resend=False):
-        if value == self.last_value and cycle_time == self.last_cycle_time:
+        if value == self.last_value and not is_resend:
-            if not is_resend:
             return
         print_time = max(print_time, self.last_print_time + PIN_MIN_TIME)
         if self.is_pwm:
-            self.mcu_pin.set_pwm(print_time, value, cycle_time)
+            self.mcu_pin.set_pwm(print_time, value)
         else:
             self.mcu_pin.set_digital(print_time, value)
         self.last_value = value
-        self.last_cycle_time = cycle_time
         self.last_print_time = print_time
         if self.resend_interval and self.resend_timer is None:
             self.resend_timer = self.reactor.register_timer(
                 self._resend_current_val, self.reactor.NOW)
     cmd_SET_PIN_help = "Set the value of an output pin"
     def cmd_SET_PIN(self, gcmd):
+        # Read requested value
         value = gcmd.get_float('VALUE', minval=0., maxval=self.scale)
         value /= self.scale
-        cycle_time = gcmd.get_float('CYCLE_TIME', self.default_cycle_time,
-                                    above=0., maxval=MAX_SCHEDULE_TIME)
         if not self.is_pwm and value not in [0., 1.]:
             raise gcmd.error("Invalid pin value")
+        # Obtain print_time and apply requested settings
         toolhead = self.printer.lookup_object('toolhead')
         toolhead.register_lookahead_callback(
-            lambda print_time: self._set_pin(print_time, value, cycle_time))
+            lambda print_time: self._set_pin(print_time, value))
 
     def _resend_current_val(self, eventtime):
         if self.last_value == self.shutdown_value:
@@ -97,8 +93,7 @@ class PrinterOutputPin:
         if time_diff > 0.:
             # Reschedule for resend time
             return systime + time_diff
-        self._set_pin(print_time + PIN_MIN_TIME,
+        self._set_pin(print_time + PIN_MIN_TIME, self.last_value, True)
-                      self.last_value, self.last_cycle_time, True)
         return systime + self.resend_interval
 
 def load_config_prefix(config):

klippy/extras/pwm_cycle_time.py

@@ -0,0 +1,123 @@
+# Handle pwm output pins with variable frequency
+#
+# Copyright (C) 2017-2023  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+
+PIN_MIN_TIME = 0.100
+MAX_SCHEDULE_TIME = 5.0
+
+class MCU_pwm_cycle:
+    def __init__(self, pin_params, cycle_time, start_value, shutdown_value):
+        self._mcu = pin_params['chip']
+        self._cycle_time = cycle_time
+        self._oid = None
+        self._mcu.register_config_callback(self._build_config)
+        self._pin = pin_params['pin']
+        self._invert = pin_params['invert']
+        if self._invert:
+            start_value = 1. - start_value
+            shutdown_value = 1. - shutdown_value
+        self._start_value = max(0., min(1., start_value))
+        self._shutdown_value = max(0., min(1., shutdown_value))
+        self._last_clock = self._cycle_ticks = 0
+        self._set_cmd = self._set_cycle_ticks = None
+    def _build_config(self):
+        cmd_queue = self._mcu.alloc_command_queue()
+        curtime = self._mcu.get_printer().get_reactor().monotonic()
+        printtime = self._mcu.estimated_print_time(curtime)
+        self._last_clock = self._mcu.print_time_to_clock(printtime + 0.200)
+        cycle_ticks = self._mcu.seconds_to_clock(self._cycle_time)
+        if self._shutdown_value not in [0., 1.]:
+            raise self._mcu.get_printer().config_error(
+                "shutdown value must be 0.0 or 1.0 on soft pwm")
+        if cycle_ticks >= 1<<31:
+            raise self._mcu.get_printer().config_error(
+                "PWM pin cycle time too large")
+        self._mcu.request_move_queue_slot()
+        self._oid = self._mcu.create_oid()
+        self._mcu.add_config_cmd(
+            "config_digital_out oid=%d pin=%s value=%d"
+            " default_value=%d max_duration=%d"
+            % (self._oid, self._pin, self._start_value >= 1.0,
+               self._shutdown_value >= 0.5, 0))
+        self._mcu.add_config_cmd(
+            "set_digital_out_pwm_cycle oid=%d cycle_ticks=%d"
+            % (self._oid, cycle_ticks))
+        self._cycle_ticks = cycle_ticks
+        svalue = int(self._start_value * cycle_ticks + 0.5)
+        self._mcu.add_config_cmd(
+            "queue_digital_out oid=%d clock=%d on_ticks=%d"
+            % (self._oid, self._last_clock, svalue), is_init=True)
+        self._set_cmd = self._mcu.lookup_command(
+            "queue_digital_out oid=%c clock=%u on_ticks=%u", cq=cmd_queue)
+        self._set_cycle_ticks = self._mcu.lookup_command(
+            "set_digital_out_pwm_cycle oid=%c cycle_ticks=%u", cq=cmd_queue)
+    def set_pwm_cycle(self, print_time, value, cycle_time):
+        clock = self._mcu.print_time_to_clock(print_time)
+        minclock = self._last_clock
+        # Send updated cycle_time if necessary
+        cycle_ticks = self._mcu.seconds_to_clock(cycle_time)
+        if cycle_ticks != self._cycle_ticks:
+            if cycle_ticks >= 1<<31:
+                raise self._mcu.get_printer().command_error(
+                    "PWM cycle time too large")
+            self._set_cycle_ticks.send([self._oid, cycle_ticks],
+                                       minclock=minclock, reqclock=clock)
+            self._cycle_ticks = cycle_ticks
+        # Send pwm update
+        if self._invert:
+            value = 1. - value
+        v = int(max(0., min(1., value)) * float(self._cycle_ticks) + 0.5)
+        self._set_cmd.send([self._oid, clock, v],
+                           minclock=self._last_clock, reqclock=clock)
+        self._last_clock = clock
+
+class PrinterOutputPWMCycle:
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.last_print_time = 0.
+        cycle_time = config.getfloat('cycle_time', 0.100, above=0.,
+                                     maxval=MAX_SCHEDULE_TIME)
+        self.last_cycle_time = self.default_cycle_time = cycle_time
+        # Determine start and shutdown values
+        self.scale = config.getfloat('scale', 1., above=0.)
+        self.last_value = config.getfloat(
+            'value', 0., minval=0., maxval=self.scale) / self.scale
+        self.shutdown_value = config.getfloat(
+            'shutdown_value', 0., minval=0., maxval=self.scale) / self.scale
+        # Create pwm pin object
+        ppins = self.printer.lookup_object('pins')
+        pin_params = ppins.lookup_pin(config.get('pin'), can_invert=True)
+        self.mcu_pin = MCU_pwm_cycle(pin_params, cycle_time,
+                                     self.last_value, self.shutdown_value)
+        # Register commands
+        pin_name = config.get_name().split()[1]
+        gcode = self.printer.lookup_object('gcode')
+        gcode.register_mux_command("SET_PIN", "PIN", pin_name,
+                                   self.cmd_SET_PIN,
+                                   desc=self.cmd_SET_PIN_help)
+    def get_status(self, eventtime):
+        return {'value': self.last_value}
+    def _set_pin(self, print_time, value, cycle_time):
+        if value == self.last_value and cycle_time == self.last_cycle_time:
+            return
+        print_time = max(print_time, self.last_print_time + PIN_MIN_TIME)
+        self.mcu_pin.set_pwm_cycle(print_time, value, cycle_time)
+        self.last_value = value
+        self.last_cycle_time = cycle_time
+        self.last_print_time = print_time
+    cmd_SET_PIN_help = "Set the value of an output pin"
+    def cmd_SET_PIN(self, gcmd):
+        # Read requested value
+        value = gcmd.get_float('VALUE', minval=0., maxval=self.scale)
+        value /= self.scale
+        cycle_time = gcmd.get_float('CYCLE_TIME', self.default_cycle_time,
+                                    above=0., maxval=MAX_SCHEDULE_TIME)
+        # Obtain print_time and apply requested settings
+        toolhead = self.printer.lookup_object('toolhead')
+        toolhead.register_lookahead_callback(
+            lambda print_time: self._set_pin(print_time, value, cycle_time))
+
+def load_config_prefix(config):
+    return PrinterOutputPWMCycle(config)

test/klippy/pwm.cfg

@@ -5,6 +5,12 @@ value: 0
 shutdown_value: 0
 cycle_time: 0.01
 
+[pwm_cycle_time cycle_pwm_pin]
+pin: PH7
+value: 0
+shutdown_value: 0
+cycle_time: 0.01
+
 [output_pin hard_pwm_pin]
 pin: PH6
 pwm: True

test/klippy/pwm.test

@@ -16,18 +16,24 @@ SET_PIN PIN=soft_pwm_pin VALUE=0
 SET_PIN PIN=soft_pwm_pin VALUE=0.5
 SET_PIN PIN=soft_pwm_pin VALUE=1
 
+# Soft PWM with dynamic cycle time
+# Test basic on off
+SET_PIN PIN=cycle_pwm_pin VALUE=0
+SET_PIN PIN=cycle_pwm_pin VALUE=0.5
+SET_PIN PIN=cycle_pwm_pin VALUE=1
+
 # Test cycle time
-SET_PIN PIN=soft_pwm_pin VALUE=0 CYCLE_TIME=0.1
+SET_PIN PIN=cycle_pwm_pin VALUE=0 CYCLE_TIME=0.1
-SET_PIN PIN=soft_pwm_pin VALUE=1 CYCLE_TIME=0.5
+SET_PIN PIN=cycle_pwm_pin VALUE=1 CYCLE_TIME=0.5
-SET_PIN PIN=soft_pwm_pin VALUE=0.5 CYCLE_TIME=0.001
+SET_PIN PIN=cycle_pwm_pin VALUE=0.5 CYCLE_TIME=0.001
-SET_PIN PIN=soft_pwm_pin VALUE=0.75 CYCLE_TIME=0.01
+SET_PIN PIN=cycle_pwm_pin VALUE=0.75 CYCLE_TIME=0.01
-SET_PIN PIN=soft_pwm_pin VALUE=0.5 CYCLE_TIME=1
+SET_PIN PIN=cycle_pwm_pin VALUE=0.5 CYCLE_TIME=1
 
 # Test duplicate values
-SET_PIN PIN=soft_pwm_pin VALUE=0.5 CYCLE_TIME=0.5
+SET_PIN PIN=cycle_pwm_pin VALUE=0.5 CYCLE_TIME=0.5
-SET_PIN PIN=soft_pwm_pin VALUE=0.5 CYCLE_TIME=0.5
+SET_PIN PIN=cycle_pwm_pin VALUE=0.5 CYCLE_TIME=0.5
-SET_PIN PIN=soft_pwm_pin VALUE=0.75 CYCLE_TIME=0.5
+SET_PIN PIN=cycle_pwm_pin VALUE=0.75 CYCLE_TIME=0.5
-SET_PIN PIN=soft_pwm_pin VALUE=0.75 CYCLE_TIME=0.75
+SET_PIN PIN=cycle_pwm_pin VALUE=0.75 CYCLE_TIME=0.75
 
 # PWM tool
 # Basic test