272 lines
12 KiB
Python
272 lines
12 KiB
Python
# Support for reading acceleration data from an adxl345 chip
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#
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# Copyright (C) 2020 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, multiprocessing, os
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from . import bus
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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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SCALE = 0.004 * 9.80665 * 1000. # 4mg/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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# Sample results
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class ADXL345Results:
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def __init__(self):
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self.raw_samples = None
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self.samples = []
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self.drops = self.overflows = 0
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self.time_per_sample = self.start_range = self.end_range = 0.
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def get_stats(self):
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return ("drops=%d,overflows=%d"
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",time_per_sample=%.9f,start_range=%.6f,end_range=%.6f"
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% (self.drops, self.overflows,
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self.time_per_sample, self.start_range, self.end_range))
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def setup_data(self, axes_map, raw_samples, end_sequence, overflows,
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start1_time, start2_time, end1_time, end2_time):
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if not raw_samples or not end_sequence:
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return
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self.axes_map = axes_map
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self.raw_samples = raw_samples
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self.overflows = overflows
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self.start2_time = start2_time
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self.start_range = start2_time - start1_time
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self.end_range = end2_time - end1_time
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self.total_count = (end_sequence - 1) * 8 + len(raw_samples[-1][1]) // 6
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total_time = end2_time - start2_time
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self.time_per_sample = time_per_sample = total_time / self.total_count
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self.seq_to_time = time_per_sample * 8.
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actual_count = sum([len(data)//6 for _, data in raw_samples])
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self.drops = self.total_count - actual_count
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def decode_samples(self):
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if not self.raw_samples:
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return self.samples
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(x_pos, x_scale), (y_pos, y_scale), (z_pos, z_scale) = self.axes_map
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actual_count = 0
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self.samples = samples = [None] * self.total_count
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for seq, data in self.raw_samples:
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d = bytearray(data)
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count = len(data)
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sdata = [(d[i] | (d[i+1] << 8)) - ((d[i+1] & 0x80) << 9)
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for i in range(0, count-1, 2)]
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seq_time = self.start2_time + seq * self.seq_to_time
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for i in range(count//6):
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samp_time = seq_time + i * self.time_per_sample
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x = sdata[i*3 + x_pos] * x_scale
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y = sdata[i*3 + y_pos] * y_scale
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z = sdata[i*3 + z_pos] * z_scale
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samples[actual_count] = Accel_Measurement(samp_time, x, y, z)
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actual_count += 1
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del samples[actual_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("##%s\n#time,accel_x,accel_y,accel_z\n" % (
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self.get_stats(),))
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samples = self.samples or self.decode_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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# Printer class that controls measurments
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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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self.query_rate = 0
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self.last_tx_time = 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.get('axes_map', 'x,y,z').split(',')
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if len(axes_map) != 3 or any([a.strip() 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.raw_samples = []
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self.last_sequence = 0
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self.samples_start1 = self.samples_start2 = 0.
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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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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_start, "adxl345_start", oid)
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mcu.register_response(self._handle_adxl345_data, "adxl345_data", oid)
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# Register commands
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name = "default"
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if len(config.get_name().split()) > 1:
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name = config.get_name().split()[1]
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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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if name == "default":
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gcode.register_mux_command("ACCELEROMETER_MEASURE", "CHIP", None,
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self.cmd_ACCELEROMETER_MEASURE)
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gcode.register_mux_command("ACCELEROMETER_QUERY", "CHIP", None,
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self.cmd_ACCELEROMETER_QUERY)
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def _build_config(self):
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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",
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cq=self.spi.get_command_queue())
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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_end oid=%c end1_time=%u end2_time=%u"
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" limit_count=%hu sequence=%hu",
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oid=self.oid, cq=self.spi.get_command_queue())
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def _clock_to_print_time(self, clock):
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return self.mcu.clock_to_print_time(self.mcu.clock32_to_clock64(clock))
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def _handle_adxl345_start(self, params):
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self.samples_start1 = self._clock_to_print_time(params['start1_time'])
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self.samples_start2 = self._clock_to_print_time(params['start2_time'])
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def _handle_adxl345_data(self, params):
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last_sequence = self.last_sequence
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sequence = (last_sequence & ~0xffff) | params['sequence']
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if sequence < last_sequence:
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sequence += 0x10000
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self.last_sequence = sequence
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raw_samples = self.raw_samples
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if len(raw_samples) >= 300000:
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# Avoid filling up memory with too many samples
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return
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raw_samples.append((sequence, params['data']))
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def _convert_sequence(self, sequence):
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sequence = (self.last_sequence & ~0xffff) | sequence
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if sequence < self.last_sequence:
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sequence += 0x10000
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return sequence
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def start_measurements(self, rate=None):
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rate = rate or self.data_rate
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# Verify chip connectivity
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params = self.spi.spi_transfer([REG_DEVID | REG_MOD_READ, 0x00])
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response = bytearray(params['response'])
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if response[1] != 0xe5:
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raise self.printer.command_error("Invalid adxl345 id (got %x vs %x)"
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% (response[1], 0xe5))
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# Setup chip in requested query rate
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clock = 0
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if self.last_tx_time:
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clock = self.mcu.print_time_to_clock(self.last_tx_time)
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self.spi.spi_send([REG_POWER_CTL, 0x00], minclock=clock)
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self.spi.spi_send([REG_FIFO_CTL, 0x00])
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self.spi.spi_send([REG_DATA_FORMAT, 0x0B])
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self.spi.spi_send([REG_BW_RATE, QUERY_RATES[rate]])
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self.spi.spi_send([REG_FIFO_CTL, 0x80])
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# Setup samples
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print_time = self.printer.lookup_object('toolhead').get_last_move_time()
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self.raw_samples = []
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self.last_sequence = 0
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self.samples_start1 = self.samples_start2 = print_time
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# Start bulk reading
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reqclock = self.mcu.print_time_to_clock(print_time)
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rest_ticks = self.mcu.seconds_to_clock(4. / rate)
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self.last_tx_time = print_time
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self.query_rate = rate
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self.query_adxl345_cmd.send([self.oid, reqclock, rest_ticks],
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reqclock=reqclock)
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def finish_measurements(self):
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query_rate = self.query_rate
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if not query_rate:
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return ADXL345Results()
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# Halt bulk reading
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print_time = self.printer.lookup_object('toolhead').get_last_move_time()
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clock = self.mcu.print_time_to_clock(print_time)
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params = self.query_adxl345_end_cmd.send([self.oid, 0, 0],
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minclock=clock)
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self.last_tx_time = print_time
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self.query_rate = 0
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raw_samples = self.raw_samples
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self.raw_samples = []
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# Generate results
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end1_time = self._clock_to_print_time(params['end1_time'])
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end2_time = self._clock_to_print_time(params['end2_time'])
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end_sequence = self._convert_sequence(params['sequence'])
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overflows = params['limit_count']
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res = ADXL345Results()
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res.setup_data(self.axes_map, raw_samples, end_sequence, overflows,
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self.samples_start1, self.samples_start2,
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end1_time, end2_time)
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logging.info("ADXL345 finished %d measurements: %s",
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res.total_count, res.get_stats())
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return res
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def end_query(self, name):
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if not self.query_rate:
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return
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res = self.finish_measurements()
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# Write data to file
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filename = "/tmp/adxl345-%s.csv" % (name,)
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res.write_to_file(filename)
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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.query_rate:
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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 adxl345 NAME parameter")
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self.end_query(name)
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gcmd.respond_info("adxl345 measurements stopped")
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else:
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rate = gcmd.get_int("RATE", self.data_rate)
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if rate not in QUERY_RATES:
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raise gcmd.error("Not a valid adxl345 query rate: %d" % (rate,))
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self.start_measurements(rate)
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gcmd.respond_info("adxl345 measurements started")
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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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if self.query_rate:
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raise gcmd.error("adxl345 measurements in progress")
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self.start_measurements()
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reactor = self.printer.get_reactor()
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eventtime = starttime = reactor.monotonic()
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while not self.raw_samples:
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eventtime = reactor.pause(eventtime + .1)
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if eventtime > starttime + 3.:
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# Try to shutdown the measurements
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self.finish_measurements()
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raise gcmd.error("Timeout reading adxl345 data")
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result = self.finish_measurements()
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values = result.decode_samples()
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_, accel_x, accel_y, accel_z = values[-1]
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gcmd.respond_info("adxl345 values (x, y, z): %.6f, %.6f, %.6f" % (
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accel_x, accel_y, accel_z))
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def load_config(config):
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return ADXL345(config)
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def load_config_prefix(config):
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return ADXL345(config)
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