445 lines
20 KiB
Python
445 lines
20 KiB
Python
# Support for reading acceleration data from an adxl345 chip
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#
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# Copyright (C) 2020-2021 Kevin O'Connor <kevin@koconnor.net>
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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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import logging, time, collections, threading, multiprocessing, os
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from . import bus, motion_report
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# ADXL345 registers
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REG_DEVID = 0x00
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REG_BW_RATE = 0x2C
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REG_POWER_CTL = 0x2D
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REG_DATA_FORMAT = 0x31
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REG_FIFO_CTL = 0x38
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REG_MOD_READ = 0x80
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REG_MOD_MULTI = 0x40
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QUERY_RATES = {
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25: 0x8, 50: 0x9, 100: 0xa, 200: 0xb, 400: 0xc,
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800: 0xd, 1600: 0xe, 3200: 0xf,
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}
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ADXL345_DEV_ID = 0xe5
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SET_FIFO_CTL = 0x90
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FREEFALL_ACCEL = 9.80665 * 1000.
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SCALE = 0.0039 * FREEFALL_ACCEL # 3.9mg/LSB * Earth gravity in mm/s**2
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Accel_Measurement = collections.namedtuple(
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'Accel_Measurement', ('time', 'accel_x', 'accel_y', 'accel_z'))
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# Helper class to obtain measurements
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class AccelQueryHelper:
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def __init__(self, printer, cconn):
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self.printer = printer
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self.cconn = cconn
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print_time = printer.lookup_object('toolhead').get_last_move_time()
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self.request_start_time = self.request_end_time = print_time
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self.samples = self.raw_samples = []
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def finish_measurements(self):
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toolhead = self.printer.lookup_object('toolhead')
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self.request_end_time = toolhead.get_last_move_time()
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toolhead.wait_moves()
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self.cconn.finalize()
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def _get_raw_samples(self):
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raw_samples = self.cconn.get_messages()
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if raw_samples:
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self.raw_samples = raw_samples
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return self.raw_samples
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def has_valid_samples(self):
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raw_samples = self._get_raw_samples()
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for msg in raw_samples:
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data = msg['params']['data']
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first_sample_time = data[0][0]
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last_sample_time = data[-1][0]
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if (first_sample_time > self.request_end_time
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or last_sample_time < self.request_start_time):
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continue
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# The time intervals [first_sample_time, last_sample_time]
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# and [request_start_time, request_end_time] have non-zero
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# intersection. It is still theoretically possible that none
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# of the samples from raw_samples fall into the time interval
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# [request_start_time, request_end_time] if it is too narrow
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# or on very heavy data losses. In practice, that interval
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# is at least 1 second, so this possibility is negligible.
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return True
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return False
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def get_samples(self):
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raw_samples = self._get_raw_samples()
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if not raw_samples:
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return self.samples
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total = sum([len(m['params']['data']) for m in raw_samples])
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count = 0
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self.samples = samples = [None] * total
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for msg in raw_samples:
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for samp_time, x, y, z in msg['params']['data']:
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if samp_time < self.request_start_time:
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continue
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if samp_time > self.request_end_time:
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break
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samples[count] = Accel_Measurement(samp_time, x, y, z)
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count += 1
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del samples[count:]
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return self.samples
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def write_to_file(self, filename):
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def write_impl():
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try:
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# Try to re-nice writing process
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os.nice(20)
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except:
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pass
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f = open(filename, "w")
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f.write("#time,accel_x,accel_y,accel_z\n")
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samples = self.samples or self.get_samples()
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for t, accel_x, accel_y, accel_z in samples:
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f.write("%.6f,%.6f,%.6f,%.6f\n" % (
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t, accel_x, accel_y, accel_z))
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f.close()
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write_proc = multiprocessing.Process(target=write_impl)
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write_proc.daemon = True
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write_proc.start()
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# Helper class for G-Code commands
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class AccelCommandHelper:
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def __init__(self, config, chip):
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self.printer = config.get_printer()
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self.chip = chip
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self.bg_client = None
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name_parts = config.get_name().split()
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self.base_name = name_parts[0]
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self.name = name_parts[-1]
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self.register_commands(self.name)
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if len(name_parts) == 1:
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if self.name == "adxl345" or not config.has_section("adxl345"):
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self.register_commands(None)
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def register_commands(self, name):
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# Register commands
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gcode = self.printer.lookup_object('gcode')
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gcode.register_mux_command("ACCELEROMETER_MEASURE", "CHIP", name,
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self.cmd_ACCELEROMETER_MEASURE,
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desc=self.cmd_ACCELEROMETER_MEASURE_help)
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gcode.register_mux_command("ACCELEROMETER_QUERY", "CHIP", name,
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self.cmd_ACCELEROMETER_QUERY,
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desc=self.cmd_ACCELEROMETER_QUERY_help)
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gcode.register_mux_command("ACCELEROMETER_DEBUG_READ", "CHIP", name,
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self.cmd_ACCELEROMETER_DEBUG_READ,
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desc=self.cmd_ACCELEROMETER_DEBUG_READ_help)
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gcode.register_mux_command("ACCELEROMETER_DEBUG_WRITE", "CHIP", name,
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self.cmd_ACCELEROMETER_DEBUG_WRITE,
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desc=self.cmd_ACCELEROMETER_DEBUG_WRITE_help)
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cmd_ACCELEROMETER_MEASURE_help = "Start/stop accelerometer"
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def cmd_ACCELEROMETER_MEASURE(self, gcmd):
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if self.bg_client is None:
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# Start measurements
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self.bg_client = self.chip.start_internal_client()
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gcmd.respond_info("accelerometer measurements started")
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return
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# End measurements
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name = gcmd.get("NAME", time.strftime("%Y%m%d_%H%M%S"))
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if not name.replace('-', '').replace('_', '').isalnum():
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raise gcmd.error("Invalid NAME parameter")
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bg_client = self.bg_client
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self.bg_client = None
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bg_client.finish_measurements()
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# Write data to file
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if self.base_name == self.name:
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filename = "/tmp/%s-%s.csv" % (self.base_name, name)
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else:
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filename = "/tmp/%s-%s-%s.csv" % (self.base_name, self.name, name)
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bg_client.write_to_file(filename)
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gcmd.respond_info("Writing raw accelerometer data to %s file"
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% (filename,))
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cmd_ACCELEROMETER_QUERY_help = "Query accelerometer for the current values"
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def cmd_ACCELEROMETER_QUERY(self, gcmd):
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aclient = self.chip.start_internal_client()
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self.printer.lookup_object('toolhead').dwell(1.)
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aclient.finish_measurements()
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values = aclient.get_samples()
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if not values:
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raise gcmd.error("No accelerometer measurements found")
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_, accel_x, accel_y, accel_z = values[-1]
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gcmd.respond_info("accelerometer values (x, y, z): %.6f, %.6f, %.6f"
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% (accel_x, accel_y, accel_z))
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cmd_ACCELEROMETER_DEBUG_READ_help = "Query register (for debugging)"
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def cmd_ACCELEROMETER_DEBUG_READ(self, gcmd):
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reg = gcmd.get("REG", minval=0, maxval=126, parser=lambda x: int(x, 0))
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val = self.chip.read_reg(reg)
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gcmd.respond_info("Accelerometer REG[0x%x] = 0x%x" % (reg, val))
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cmd_ACCELEROMETER_DEBUG_WRITE_help = "Set register (for debugging)"
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def cmd_ACCELEROMETER_DEBUG_WRITE(self, gcmd):
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reg = gcmd.get("REG", minval=0, maxval=126, parser=lambda x: int(x, 0))
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val = gcmd.get("VAL", minval=0, maxval=255, parser=lambda x: int(x, 0))
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self.chip.set_reg(reg, val)
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# Helper class for chip clock synchronization via linear regression
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class ClockSyncRegression:
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def __init__(self, mcu, chip_clock_smooth, decay = 1. / 20.):
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self.mcu = mcu
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self.chip_clock_smooth = chip_clock_smooth
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self.decay = decay
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self.last_chip_clock = self.last_exp_mcu_clock = 0.
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self.mcu_clock_avg = self.mcu_clock_variance = 0.
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self.chip_clock_avg = self.chip_clock_covariance = 0.
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def reset(self, mcu_clock, chip_clock):
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self.mcu_clock_avg = self.last_mcu_clock = mcu_clock
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self.chip_clock_avg = chip_clock
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self.mcu_clock_variance = self.chip_clock_covariance = 0.
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self.last_chip_clock = self.last_exp_mcu_clock = 0.
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def update(self, mcu_clock, chip_clock):
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# Update linear regression
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decay = self.decay
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diff_mcu_clock = mcu_clock - self.mcu_clock_avg
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self.mcu_clock_avg += decay * diff_mcu_clock
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self.mcu_clock_variance = (1. - decay) * (
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self.mcu_clock_variance + diff_mcu_clock**2 * decay)
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diff_chip_clock = chip_clock - self.chip_clock_avg
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self.chip_clock_avg += decay * diff_chip_clock
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self.chip_clock_covariance = (1. - decay) * (
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self.chip_clock_covariance + diff_mcu_clock*diff_chip_clock*decay)
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def set_last_chip_clock(self, chip_clock):
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base_mcu, base_chip, inv_cfreq = self.get_clock_translation()
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self.last_chip_clock = chip_clock
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self.last_exp_mcu_clock = base_mcu + (chip_clock-base_chip) * inv_cfreq
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def get_clock_translation(self):
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inv_chip_freq = self.mcu_clock_variance / self.chip_clock_covariance
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if not self.last_chip_clock:
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return self.mcu_clock_avg, self.chip_clock_avg, inv_chip_freq
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# Find mcu clock associated with future chip_clock
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s_chip_clock = self.last_chip_clock + self.chip_clock_smooth
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scdiff = s_chip_clock - self.chip_clock_avg
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s_mcu_clock = self.mcu_clock_avg + scdiff * inv_chip_freq
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# Calculate frequency to converge at future point
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mdiff = s_mcu_clock - self.last_exp_mcu_clock
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s_inv_chip_freq = mdiff / self.chip_clock_smooth
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return self.last_exp_mcu_clock, self.last_chip_clock, s_inv_chip_freq
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def get_time_translation(self):
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base_mcu, base_chip, inv_cfreq = self.get_clock_translation()
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clock_to_print_time = self.mcu.clock_to_print_time
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base_time = clock_to_print_time(base_mcu)
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inv_freq = clock_to_print_time(base_mcu + inv_cfreq) - base_time
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return base_time, base_chip, inv_freq
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MIN_MSG_TIME = 0.100
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BYTES_PER_SAMPLE = 5
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SAMPLES_PER_BLOCK = 10
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# Printer class that controls ADXL345 chip
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class ADXL345:
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def __init__(self, config):
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self.printer = config.get_printer()
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AccelCommandHelper(config, self)
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self.query_rate = 0
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am = {'x': (0, SCALE), 'y': (1, SCALE), 'z': (2, SCALE),
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'-x': (0, -SCALE), '-y': (1, -SCALE), '-z': (2, -SCALE)}
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axes_map = config.getlist('axes_map', ('x','y','z'), count=3)
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if any([a not in am for a in axes_map]):
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raise config.error("Invalid adxl345 axes_map parameter")
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self.axes_map = [am[a.strip()] for a in axes_map]
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self.data_rate = config.getint('rate', 3200)
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if self.data_rate not in QUERY_RATES:
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raise config.error("Invalid rate parameter: %d" % (self.data_rate,))
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# Measurement storage (accessed from background thread)
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self.lock = threading.Lock()
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self.raw_samples = []
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# Setup mcu sensor_adxl345 bulk query code
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self.spi = bus.MCU_SPI_from_config(config, 3, default_speed=5000000)
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self.mcu = mcu = self.spi.get_mcu()
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self.oid = oid = mcu.create_oid()
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self.query_adxl345_cmd = self.query_adxl345_end_cmd = None
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self.query_adxl345_status_cmd = None
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mcu.add_config_cmd("config_adxl345 oid=%d spi_oid=%d"
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% (oid, self.spi.get_oid()))
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mcu.add_config_cmd("query_adxl345 oid=%d clock=0 rest_ticks=0"
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% (oid,), on_restart=True)
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mcu.register_config_callback(self._build_config)
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mcu.register_response(self._handle_adxl345_data, "adxl345_data", oid)
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# Clock tracking
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self.last_sequence = self.max_query_duration = 0
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self.last_limit_count = self.last_error_count = 0
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self.clock_sync = ClockSyncRegression(self.mcu, 640)
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# API server endpoints
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self.api_dump = motion_report.APIDumpHelper(
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self.printer, self._api_update, self._api_startstop, 0.100)
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self.name = config.get_name().split()[-1]
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wh = self.printer.lookup_object('webhooks')
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wh.register_mux_endpoint("adxl345/dump_adxl345", "sensor", self.name,
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self._handle_dump_adxl345)
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def _build_config(self):
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cmdqueue = self.spi.get_command_queue()
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self.query_adxl345_cmd = self.mcu.lookup_command(
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"query_adxl345 oid=%c clock=%u rest_ticks=%u", cq=cmdqueue)
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self.query_adxl345_end_cmd = self.mcu.lookup_query_command(
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"query_adxl345 oid=%c clock=%u rest_ticks=%u",
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"adxl345_status oid=%c clock=%u query_ticks=%u next_sequence=%hu"
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" buffered=%c fifo=%c limit_count=%hu", oid=self.oid, cq=cmdqueue)
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self.query_adxl345_status_cmd = self.mcu.lookup_query_command(
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"query_adxl345_status oid=%c",
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"adxl345_status oid=%c clock=%u query_ticks=%u next_sequence=%hu"
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" buffered=%c fifo=%c limit_count=%hu", oid=self.oid, cq=cmdqueue)
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def read_reg(self, reg):
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params = self.spi.spi_transfer([reg | REG_MOD_READ, 0x00])
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response = bytearray(params['response'])
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return response[1]
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def set_reg(self, reg, val, minclock=0):
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self.spi.spi_send([reg, val & 0xFF], minclock=minclock)
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stored_val = self.read_reg(reg)
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if stored_val != val:
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raise self.printer.command_error(
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"Failed to set ADXL345 register [0x%x] to 0x%x: got 0x%x. "
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"This is generally indicative of connection problems "
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"(e.g. faulty wiring) or a faulty adxl345 chip." % (
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reg, val, stored_val))
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# Measurement collection
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def is_measuring(self):
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return self.query_rate > 0
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def _handle_adxl345_data(self, params):
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with self.lock:
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self.raw_samples.append(params)
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def _extract_samples(self, raw_samples):
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# Load variables to optimize inner loop below
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(x_pos, x_scale), (y_pos, y_scale), (z_pos, z_scale) = self.axes_map
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last_sequence = self.last_sequence
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time_base, chip_base, inv_freq = self.clock_sync.get_time_translation()
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# Process every message in raw_samples
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count = seq = 0
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samples = [None] * (len(raw_samples) * SAMPLES_PER_BLOCK)
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for params in raw_samples:
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seq_diff = (last_sequence - params['sequence']) & 0xffff
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seq_diff -= (seq_diff & 0x8000) << 1
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seq = last_sequence - seq_diff
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d = bytearray(params['data'])
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msg_cdiff = seq * SAMPLES_PER_BLOCK - chip_base
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for i in range(len(d) // BYTES_PER_SAMPLE):
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d_xyz = d[i*BYTES_PER_SAMPLE:(i+1)*BYTES_PER_SAMPLE]
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xlow, ylow, zlow, xzhigh, yzhigh = d_xyz
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if yzhigh & 0x80:
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self.last_error_count += 1
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continue
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rx = (xlow | ((xzhigh & 0x1f) << 8)) - ((xzhigh & 0x10) << 9)
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ry = (ylow | ((yzhigh & 0x1f) << 8)) - ((yzhigh & 0x10) << 9)
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rz = ((zlow | ((xzhigh & 0xe0) << 3) | ((yzhigh & 0xe0) << 6))
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- ((yzhigh & 0x40) << 7))
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raw_xyz = (rx, ry, rz)
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x = round(raw_xyz[x_pos] * x_scale, 6)
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y = round(raw_xyz[y_pos] * y_scale, 6)
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z = round(raw_xyz[z_pos] * z_scale, 6)
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ptime = round(time_base + (msg_cdiff + i) * inv_freq, 6)
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samples[count] = (ptime, x, y, z)
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count += 1
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self.clock_sync.set_last_chip_clock(seq * SAMPLES_PER_BLOCK + i)
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del samples[count:]
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return samples
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def _update_clock(self, minclock=0):
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# Query current state
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for retry in range(5):
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params = self.query_adxl345_status_cmd.send([self.oid],
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minclock=minclock)
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fifo = params['fifo'] & 0x7f
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if fifo <= 32:
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break
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else:
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raise self.printer.command_error("Unable to query adxl345 fifo")
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mcu_clock = self.mcu.clock32_to_clock64(params['clock'])
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sequence = (self.last_sequence & ~0xffff) | params['next_sequence']
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if sequence < self.last_sequence:
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sequence += 0x10000
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self.last_sequence = sequence
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buffered = params['buffered']
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limit_count = (self.last_limit_count & ~0xffff) | params['limit_count']
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if limit_count < self.last_limit_count:
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limit_count += 0x10000
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self.last_limit_count = limit_count
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duration = params['query_ticks']
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if duration > self.max_query_duration:
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# Skip measurement as a high query time could skew clock tracking
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self.max_query_duration = max(2 * self.max_query_duration,
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self.mcu.seconds_to_clock(.000005))
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return
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self.max_query_duration = 2 * duration
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msg_count = (sequence * SAMPLES_PER_BLOCK
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+ buffered // BYTES_PER_SAMPLE + fifo)
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# The "chip clock" is the message counter plus .5 for average
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# inaccuracy of query responses and plus .5 for assumed offset
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# of adxl345 hw processing time.
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chip_clock = msg_count + 1
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self.clock_sync.update(mcu_clock + duration // 2, chip_clock)
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def _start_measurements(self):
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if self.is_measuring():
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return
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# In case of miswiring, testing ADXL345 device ID prevents treating
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# noise or wrong signal as a correctly initialized device
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dev_id = self.read_reg(REG_DEVID)
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if dev_id != ADXL345_DEV_ID:
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raise self.printer.command_error(
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"Invalid adxl345 id (got %x vs %x).\n"
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"This is generally indicative of connection problems\n"
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"(e.g. faulty wiring) or a faulty adxl345 chip."
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% (dev_id, ADXL345_DEV_ID))
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# Setup chip in requested query rate
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self.set_reg(REG_POWER_CTL, 0x00)
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self.set_reg(REG_DATA_FORMAT, 0x0B)
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self.set_reg(REG_FIFO_CTL, 0x00)
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self.set_reg(REG_BW_RATE, QUERY_RATES[self.data_rate])
|
|
self.set_reg(REG_FIFO_CTL, SET_FIFO_CTL)
|
|
# Setup samples
|
|
with self.lock:
|
|
self.raw_samples = []
|
|
# Start bulk reading
|
|
systime = self.printer.get_reactor().monotonic()
|
|
print_time = self.mcu.estimated_print_time(systime) + MIN_MSG_TIME
|
|
reqclock = self.mcu.print_time_to_clock(print_time)
|
|
rest_ticks = self.mcu.seconds_to_clock(4. / self.data_rate)
|
|
self.query_rate = self.data_rate
|
|
self.query_adxl345_cmd.send([self.oid, reqclock, rest_ticks],
|
|
reqclock=reqclock)
|
|
logging.info("ADXL345 starting '%s' measurements", self.name)
|
|
# Initialize clock tracking
|
|
self.last_sequence = 0
|
|
self.last_limit_count = self.last_error_count = 0
|
|
self.clock_sync.reset(reqclock, 0)
|
|
self.max_query_duration = 1 << 31
|
|
self._update_clock(minclock=reqclock)
|
|
self.max_query_duration = 1 << 31
|
|
def _finish_measurements(self):
|
|
if not self.is_measuring():
|
|
return
|
|
# Halt bulk reading
|
|
params = self.query_adxl345_end_cmd.send([self.oid, 0, 0])
|
|
self.query_rate = 0
|
|
with self.lock:
|
|
self.raw_samples = []
|
|
logging.info("ADXL345 finished '%s' measurements", self.name)
|
|
# API interface
|
|
def _api_update(self, eventtime):
|
|
self._update_clock()
|
|
with self.lock:
|
|
raw_samples = self.raw_samples
|
|
self.raw_samples = []
|
|
if not raw_samples:
|
|
return {}
|
|
samples = self._extract_samples(raw_samples)
|
|
if not samples:
|
|
return {}
|
|
return {'data': samples, 'errors': self.last_error_count,
|
|
'overflows': self.last_limit_count}
|
|
def _api_startstop(self, is_start):
|
|
if is_start:
|
|
self._start_measurements()
|
|
else:
|
|
self._finish_measurements()
|
|
def _handle_dump_adxl345(self, web_request):
|
|
self.api_dump.add_client(web_request)
|
|
hdr = ('time', 'x_acceleration', 'y_acceleration', 'z_acceleration')
|
|
web_request.send({'header': hdr})
|
|
def start_internal_client(self):
|
|
cconn = self.api_dump.add_internal_client()
|
|
return AccelQueryHelper(self.printer, cconn)
|
|
|
|
def load_config(config):
|
|
return ADXL345(config)
|
|
|
|
def load_config_prefix(config):
|
|
return ADXL345(config)
|