klipper-dgus/klippy/extras/pulse_counter.py

80 lines
3.1 KiB
Python

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