#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Gyroscope module
----------------
Created by hbldh <henrik.blidh@nedomkull.com> on 2016-04-26
"""
from __future__ import division
from __future__ import print_function
from __future__ import absolute_import
import re
import logging
from pymetawear import libmetawear
from pymetawear.exceptions import PyMetaWearException
from mbientlab.metawear.cbindings import GyroBmi160Odr, GyroBmi160Range
from pymetawear.modules.base import PyMetaWearLoggingModule, Modules, data_handler
log = logging.getLogger(__name__)
def require_bmi160(f):
def wrapper(*args, **kwargs):
if getattr(args[0], 'gyro_r_class', None) is None:
raise PyMetaWearException("There is not Gyroscope "
"module of your MetaWear board!")
return f(*args, **kwargs)
return wrapper
[docs]class GyroscopeModule(PyMetaWearLoggingModule):
"""MetaWear gyroscope module implementation.
:param ctypes.c_long board: The MetaWear board pointer value.
:param int module_id: The module id of this gyroscope
component, obtained from ``libmetawear``.
:param bool debug: If ``True``, module prints out debug information.
"""
def __init__(self, board, module_id):
super(GyroscopeModule, self).__init__(board)
self.module_id = module_id
self.high_frequency_stream = False
self.odr = {}
self.fsr = {}
self.current_odr = 0
self.current_fsr = 0
if self.module_id == Modules.MBL_MW_MODULE_NA:
# No gyroscope present!
self.gyro_r_class = None
self.gyro_o_class = None
else:
self.gyro_r_class = GyroBmi160Range
self.gyro_o_class = GyroBmi160Odr
if self.gyro_o_class is not None:
# Parse possible output data rates for this gyroscope.
for key, value in vars(self.gyro_o_class).items():
if re.search('_([0-9]+)Hz', key) and key is not None:
self.odr.update({key[1:-2]: value})
if self.gyro_r_class is not None:
# Parse possible ranges for this gyroscope.
for key, value in vars(self.gyro_r_class).items():
if re.search('_([0-9]+)dps', key) and key is not None:
self.fsr.update({key[1:-3]: value})
def __str__(self):
return "{0} {1}: Data rates (Hz): {2}, Data ranges (dps): {3}".format(
self.module_name, self.sensor_name,
[float(k) for k in sorted(self.odr.keys(),
key=lambda x: (float(x)))],
[k for k in sorted(self.fsr.keys())])
def __repr__(self):
return str(self)
@property
def module_name(self):
return "Gyroscope"
@property
def sensor_name(self):
if self.gyro_r_class is not None:
return self.gyro_r_class.__name__.replace(
'Gyro', '').replace('Range', '')
else:
return ''
@property
@require_bmi160
def data_signal(self):
if self.high_frequency_stream:
return libmetawear.mbl_mw_gyro_bmi160_get_high_freq_rotation_data_signal(
self.board)
else:
return libmetawear.mbl_mw_gyro_bmi160_get_rotation_data_signal(
self.board)
def _get_odr(self, value):
sorted_ord_keys = sorted(self.odr.keys(), key=lambda x: (float(x)))
diffs = [abs(value - float(k)) for k in sorted_ord_keys]
min_diffs = min(diffs)
if min_diffs > 0.5:
raise ValueError(
"Requested ODR ({0}) was not part of possible values: {1}".format(
value, [float(x) for x in sorted_ord_keys]))
k = sorted_ord_keys[diffs.index(min_diffs)]
return self.odr.get(k)
def _get_fsr(self, value):
sorted_ord_keys = sorted(self.fsr.keys(), key=lambda x: (float(x)))
diffs = [abs(value - float(k)) for k in sorted_ord_keys]
min_diffs = min(diffs)
if min_diffs > 0.1:
raise ValueError(
"Requested FSR ({0}) was not part of possible values: {1}".format(
value, [float(x) for x in sorted(self.fsr.keys())]))
k = sorted_ord_keys[diffs.index(min_diffs)]
return self.fsr.get(k)
@require_bmi160
def get_current_settings(self):
return "data_rate in Hz: {} data_range in deg/sec: {}".format(
self.current_odr, self.current_fsr)
@require_bmi160
def get_possible_settings(self):
return {
'data_rate': [float(x) for x in sorted(
self.odr.keys(), key=lambda x: (float(x)))],
'data_range': [x for x in sorted(self.fsr.keys())]
}
@require_bmi160
def set_settings(self, data_rate=None, data_range=None):
"""Set gyroscope settings.
Can be called with two or only one setting:
.. code-block:: python
mwclient.gyroscope.set_settings(data_rate=200.0, data_range=8.0)
will give the same result as
.. code-block:: python
mwclient.gyroscope.set_settings(data_rate=200.0)
mwclient.gyroscope.set_settings(data_range=1000.0)
albeit that the latter example makes two writes to the board.
Call :meth:`~get_possible_settings` to see which values
that can be set for this sensor.
:param float data_rate: The frequency of gyroscope updates in Hz.
:param float data_range: The measurement range in the unit ``dps``,
degrees per second.
"""
if data_rate is not None:
odr = self._get_odr(data_rate)
log.debug("Setting Gyroscope ODR to {0}".format(odr))
libmetawear.mbl_mw_gyro_bmi160_set_odr(self.board, odr)
self.current_odr = data_rate
if data_range is not None:
fsr = self._get_fsr(data_range)
log.debug("Setting Gyroscope FSR to {0}".format(fsr))
libmetawear.mbl_mw_gyro_bmi160_set_range(self.board, fsr)
self.current_fsr = data_range
if (data_rate is not None) or (data_range is not None):
libmetawear.mbl_mw_gyro_bmi160_write_config(self.board)
@require_bmi160
def notifications(self, callback=None):
"""Subscribe or unsubscribe to gyroscope notifications.
Convenience method for handling gyroscope usage.
Example:
.. code-block:: python
def handle_notification(data):
# Handle dictionary with [epoch, value] keys.
epoch = data["epoch"]
xyz = data["value"]
print(str(data))
mwclient.gyroscope.notifications(handle_notification)
:param callable callback: Gyroscope notification callback function.
If `None`, unsubscription to gyroscope notifications is registered.
"""
if callback is None:
self.stop()
self.toggle_sampling(False)
super(GyroscopeModule, self).notifications(None)
else:
super(GyroscopeModule, self).notifications(data_handler(callback))
self.toggle_sampling(True)
self.start()
@require_bmi160
def start(self):
"""Switches the gyroscope to active mode."""
libmetawear.mbl_mw_gyro_bmi160_start(self.board)
@require_bmi160
def stop(self):
"""Switches the gyroscope to standby mode."""
libmetawear.mbl_mw_gyro_bmi160_stop(self.board)
@require_bmi160
def toggle_sampling(self, enabled=True):
"""Enables or disables gyroscope sampling.
:param bool enabled: Desired state of the gyroscope.
"""
if enabled:
libmetawear.mbl_mw_gyro_bmi160_enable_rotation_sampling(self.board)
else:
libmetawear.mbl_mw_gyro_bmi160_disable_rotation_sampling(self.board)