80 lines
3.1 KiB
Python
80 lines
3.1 KiB
Python
# Support for GPIO input edge counters
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#
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# Copyright (C) 2021 Adrian Keet <arkeet@gmail.com>
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#
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# This file may be distributed under the terms of the GNU GPLv3 license.
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class MCU_counter:
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def __init__(self, printer, pin, sample_time, poll_time):
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ppins = printer.lookup_object('pins')
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pin_params = ppins.lookup_pin(pin, can_pullup=True)
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self._mcu = pin_params['chip']
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self._oid = self._mcu.create_oid()
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self._pin = pin_params['pin']
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self._pullup = pin_params['pullup']
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self._poll_time = poll_time
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self._poll_ticks = 0
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self._sample_time = sample_time
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self._callback = None
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self._last_count = 0
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self._mcu.register_config_callback(self.build_config)
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def build_config(self):
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self._mcu.add_config_cmd("config_counter oid=%d pin=%s pull_up=%d"
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% (self._oid, self._pin, self._pullup))
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clock = self._mcu.get_query_slot(self._oid)
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self._poll_ticks = self._mcu.seconds_to_clock(self._poll_time)
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sample_ticks = self._mcu.seconds_to_clock(self._sample_time)
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self._mcu.add_config_cmd(
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"query_counter oid=%d clock=%d poll_ticks=%d sample_ticks=%d"
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% (self._oid, clock, self._poll_ticks, sample_ticks), is_init=True)
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self._mcu.register_response(self._handle_counter_state,
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"counter_state", self._oid)
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# Callback is called periodically every sample_time
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def setup_callback(self, cb):
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self._callback = cb
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def _handle_counter_state(self, params):
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next_clock = self._mcu.clock32_to_clock64(params['next_clock'])
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time = self._mcu.clock_to_print_time(next_clock - self._poll_ticks)
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count_clock = self._mcu.clock32_to_clock64(params['count_clock'])
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count_time = self._mcu.clock_to_print_time(count_clock)
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# handle 32-bit counter overflow
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last_count = self._last_count
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delta_count = (params['count'] - last_count) & 0xffffffff
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count = last_count + delta_count
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self._last_count = count
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if self._callback is not None:
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self._callback(time, count, count_time)
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class FrequencyCounter:
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def __init__(self, printer, pin, sample_time, poll_time):
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self._callback = None
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self._last_time = self._last_count = None
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self._freq = 0.
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self._counter = MCU_counter(printer, pin, sample_time, poll_time)
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self._counter.setup_callback(self._counter_callback)
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def _counter_callback(self, time, count, count_time):
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if self._last_time is None: # First sample
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self._last_time = time
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else:
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delta_time = count_time - self._last_time
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if delta_time > 0:
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self._last_time = count_time
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delta_count = count - self._last_count
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self._freq = delta_count / delta_time
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else: # No counts since last sample
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self._last_time = time
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self._freq = 0.
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if self._callback is not None:
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self._callback(time, self._freq)
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self._last_count = count
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def get_frequency(self):
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return self._freq
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