"""
Contains the information about a PicoScope channel.
"""
from __future__ import annotations
import numpy as np
[docs]
class PicoScopeChannel(object):
def __init__(self, channel, enabled, coupling, voltage_range, voltage_offset,
bandwidth, max_adu_value):
"""Contains the information about a PicoScope channel.
This class is used by :class:`~.picoscope.PicoScope` and is not meant to be
called directly.
Parameters
----------
channel : :class:`enum.IntEnum`
The ``PSX000xChannel`` enum.
enabled : :class:`bool`
Whether the channel is enabled.
coupling : :class:`enum.IntEnum`
The ``PSX000xCoupling`` enum, e.g. AC or DC.
voltage_range : :class:`float`
The voltage range, in Volts.
voltage_offset : :class:`float`
The voltage offset, in Volts.
bandwidth : :class:`enum.IntEnum` or :data:`None`
The ``PSX000xBandwidthLimiter`` enum.
max_adu_value : :class:`int`
The maximum analog-to-digital unit.
"""
self._channel = channel
self._enabled = enabled
self._coupling = coupling
self._voltage_range = voltage_range
self._voltage_offset = voltage_offset
self._bandwidth = bandwidth
self._volts_per_adu = voltage_range/float(max_adu_value)
# the raw data in analog-to-digital units
self._adu_values = np.empty((0, 0), dtype=np.int16)
self._num_captures = 0
self._num_samples = 0
@property
def channel(self):
""":class:`enum.IntEnum`: The ``PSX000xChannel`` enum."""
return self._channel
@property
def enabled(self):
""":class:`bool`: Whether the channel is enabled."""
return self._enabled
@property
def coupling(self):
""":class:`enum.IntEnum`: The ``PSX000xCoupling`` enum, e.g. AC or DC."""
return self._coupling
@property
def voltage_range(self):
""":class:`float`: The voltage range, in Volts."""
return self._voltage_range
@property
def voltage_offset(self):
""":class:`float`: The voltage offset, in Volts."""
return self._voltage_offset
@property
def bandwidth(self):
""" :class:`enum.IntEnum` or :data:`None`: The ``PSX000xBandwidthLimiter`` enum."""
return self._bandwidth
@property
def volts_per_adu(self):
""":class:`float`: The conversion factor to convert ADU to volts"""
return self._volts_per_adu
@property
def raw(self):
""":class:`numpy.ndarray`: The raw data, in ADU"""
return self._adu_values
@property
def buffer(self):
""":class:`numpy.ndarray`: The raw data, in ADU"""
return self._adu_values
@property
def volts(self):
""":class:`numpy.ndarray`: The data, in volts"""
# From the manual, the voltage offset gets added to the input channel before digitization.
# Must convert the ADU values to volts and then subtract the offset.
return self._adu_values * self._volts_per_adu - self._voltage_offset
@property
def num_samples(self):
""":class:`int`: The size of the data array."""
return self._adu_values.size
[docs]
def allocate(self, num_captures, num_samples):
"""Allocate memory to save the data.
Parameters
----------
num_captures : :class:`int`
The number of captures
num_samples : :class:`int`
The number of samples
"""
if self._adu_values.size != num_captures*num_samples:
if num_captures == 1:
self._adu_values = np.empty(num_samples, dtype=np.int16)
else:
self._adu_values = np.empty((num_captures, num_samples), dtype=np.int16)