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import ctypes
from math import log2, floor
from time import time_ns, sleep
from typing import Mapping, Optional, MutableMapping, Union, Tuple
import numpy as np
from picosdk.functions import assert_pico_ok
from picosdk.library import Library
from picosdk.ps4000 import ps4000
from picosdk.ps6000 import ps6000
from public import public
from .base import Scope
def adc2volt(adc: Union[np.ndarray, ctypes.c_int16],
volt_range: float, adc_minmax: int) -> Union[np.ndarray, float]: # pragma: no cover
if isinstance(adc, ctypes.c_int16):
adc = adc.value
return (adc / adc_minmax) * volt_range
def volt2adc(volt: Union[np.ndarray, float],
volt_range: float, adc_minmax: int) -> Union[
np.ndarray, ctypes.c_int16]: # pragma: no cover
if isinstance(volt, float):
return ctypes.c_int16(int((volt / volt_range) * adc_minmax))
return (volt / volt_range) * adc_minmax
@public
class PicoScopeSdk(Scope): # pragma: no cover
"""A PicoScope based scope."""
MODULE: Library
PREFIX: str
CHANNELS: Mapping
RANGES: Mapping
MAX_ADC_VALUE: int
MIN_ADC_VALUE: int
COUPLING: Mapping
TIME_UNITS: Mapping
TRIGGERS: Mapping = {
"above": 0,
"below": 1,
"rising": 2,
"falling": 3
}
def __init__(self):
super().__init__()
self.handle: ctypes.c_int16 = ctypes.c_int16()
self.frequency: Optional[int] = None
self.samples: Optional[int] = None
self.timebase: Optional[int] = None
self.buffers: MutableMapping = {}
self.ranges: MutableMapping = {}
def open(self) -> None:
assert_pico_ok(self.__dispatch_call("OpenUnit", ctypes.byref(self.handle)))
@property
def channels(self):
return list(self.CHANNELS.keys())
def get_variant(self):
info = (ctypes.c_int8 * 6)()
size = ctypes.c_int16()
assert_pico_ok(self.__dispatch_call("GetUnitInfo", self.handle, ctypes.byref(info), 6,
ctypes.byref(size), 3))
return "".join(chr(i) for i in info[:size])
def setup_frequency(self, frequency: int, samples: int) -> Tuple[int, int]:
return self.set_frequency(frequency, samples)
# channel setup (ranges, coupling, which channel is scope vs trigger)
def set_channel(self, channel: str, enabled: bool, coupling: str, range: float):
assert_pico_ok(
self.__dispatch_call("SetChannel", self.handle, self.CHANNELS[channel], enabled,
self.COUPLING[coupling], self.RANGES[range]))
self.ranges[channel] = range
def setup_channel(self, channel: str, coupling: str, range: float, enable: bool):
self.set_channel(channel, enable, coupling, range)
def _set_freq(self, frequency: int, samples: int, period_bound: float, timebase_bound: int,
low_freq: int, high_freq: int, high_subtract: int) -> Tuple[int, int]:
period = 1 / frequency
if low_freq == 0 or period > period_bound:
tb = floor(high_freq / frequency + high_subtract)
actual_frequency = high_freq // (tb - high_subtract)
else:
tb = floor(log2(low_freq) - log2(frequency))
if tb > timebase_bound:
tb = timebase_bound
actual_frequency = low_freq // 2 ** tb
max_samples = ctypes.c_int32()
assert_pico_ok(self.__dispatch_call("GetTimebase", self.handle, tb, samples, None, 0,
ctypes.byref(max_samples), 0))
if max_samples.value < samples:
samples = max_samples.value
self.frequency = actual_frequency
self.samples = samples
self.timebase = tb
return actual_frequency, samples
# frequency setup
def set_frequency(self, frequency: int, samples: int) -> Tuple[int, int]:
raise NotImplementedError
def setup_trigger(self, channel: str, threshold: float, direction: str, delay: int,
timeout: int, enable: bool):
self.set_trigger(direction, enable, threshold, channel, delay, timeout)
# triggering setup
def set_trigger(self, type: str, enabled: bool, value: float, channel: str,
delay: int, timeout: int):
assert_pico_ok(
self.__dispatch_call("SetSimpleTrigger", self.handle, enabled,
self.CHANNELS[channel],
volt2adc(value, self.ranges[channel], self.MAX_ADC_VALUE),
self.TRIGGERS[type], delay, timeout))
def setup_capture(self, channel: str, enable: bool):
self.set_buffer(channel, enable)
# buffer setup
def set_buffer(self, channel: str, enable: bool):
if self.samples is None:
raise ValueError
if enable:
if channel in self.buffers:
del self.buffers[channel]
buffer = (ctypes.c_int16 * self.samples)()
assert_pico_ok(
self.__dispatch_call("SetDataBuffer", self.handle, self.CHANNELS[channel],
ctypes.byref(buffer), self.samples))
self.buffers[channel] = buffer
else:
assert_pico_ok(
self.__dispatch_call("SetDataBuffer", self.handle, self.CHANNELS[channel],
None, self.samples))
del self.buffers[channel]
def arm(self):
if self.samples is None or self.timebase is None:
raise ValueError
assert_pico_ok(
self.__dispatch_call("RunBlock", self.handle, 0, self.samples, self.timebase, 0,
None,
0, None, None))
def capture(self, channel: str, timeout: Optional[int] = None) -> Optional[np.ndarray]:
start = time_ns()
if self.samples is None:
raise ValueError
ready = ctypes.c_int16(0)
check = ctypes.c_int16(0)
while ready.value == check.value:
sleep(0.001)
assert_pico_ok(self.__dispatch_call("IsReady", self.handle, ctypes.byref(ready)))
if timeout is not None and (time_ns() - start) / 1e6 >= timeout:
return None
actual_samples = ctypes.c_int32(self.samples)
overflow = ctypes.c_int16()
assert_pico_ok(
self.__dispatch_call("GetValues", self.handle, 0, ctypes.byref(actual_samples), 1,
0, 0,
ctypes.byref(overflow)))
arr = np.array(self.buffers[channel], dtype=np.int16)
return adc2volt(arr, self.ranges[channel], self.MAX_ADC_VALUE)
# stop
def stop(self):
assert_pico_ok(self.__dispatch_call("Stop"))
def close(self):
assert_pico_ok(self.__dispatch_call("CloseUnit", self.handle))
def __dispatch_call(self, name, *args, **kwargs):
method = getattr(self.MODULE, self.PREFIX + name)
if method is None:
raise ValueError
return method(*args, **kwargs)
@public
class PS4000Scope(PicoScopeSdk): # pragma: no cover
MODULE = ps4000
PREFIX = "ps4000"
CHANNELS = {
"A": ps4000.PS4000_CHANNEL["PS4000_CHANNEL_A"],
"B": ps4000.PS4000_CHANNEL["PS4000_CHANNEL_B"],
"C": ps4000.PS4000_CHANNEL["PS4000_CHANNEL_C"],
"D": ps4000.PS4000_CHANNEL["PS4000_CHANNEL_D"]
}
RANGES = {
0.01: ps4000.PS4000_RANGE["PS4000_10MV"],
0.02: ps4000.PS4000_RANGE["PS4000_20MV"],
0.05: ps4000.PS4000_RANGE["PS4000_50MV"],
0.10: ps4000.PS4000_RANGE["PS4000_100MV"],
0.20: ps4000.PS4000_RANGE["PS4000_200MV"],
0.50: ps4000.PS4000_RANGE["PS4000_500MV"],
1.00: ps4000.PS4000_RANGE["PS4000_1V"],
2.00: ps4000.PS4000_RANGE["PS4000_2V"],
5.00: ps4000.PS4000_RANGE["PS4000_5V"],
10.0: ps4000.PS4000_RANGE["PS4000_10V"],
20.0: ps4000.PS4000_RANGE["PS4000_20V"],
50.0: ps4000.PS4000_RANGE["PS4000_50V"],
100.0: ps4000.PS4000_RANGE["PS4000_100V"]
}
MAX_ADC_VALUE = 32764
MIN_ADC_VALUE = -32764
COUPLING = {
"AC": ps4000.PICO_COUPLING["AC"],
"DC": ps4000.PICO_COUPLING["DC"]
}
def set_frequency(self, frequency: int, samples: int):
variant = self.get_variant()
if variant in ("4223", "4224", "4423", "4424"):
return self._set_freq(frequency, samples, 50e-9, 2, 80_000_000, 20_000_000, 1)
elif variant in ("4226", "4227"):
return self._set_freq(frequency, samples, 32e-9, 3, 250_000_000, 31_250_000, 2)
elif variant == "4262":
return self._set_freq(frequency, samples, 0, 0, 0, 10_000_000, -1)
@public
class PS6000Scope(PicoScopeSdk): # pragma: no cover
MODULE = ps6000
PREFIX = "ps6000"
CHANNELS = {
"A": ps6000.PS6000_CHANNEL["PS6000_CHANNEL_A"],
"B": ps6000.PS6000_CHANNEL["PS6000_CHANNEL_B"],
"C": ps6000.PS6000_CHANNEL["PS6000_CHANNEL_C"],
"D": ps6000.PS6000_CHANNEL["PS6000_CHANNEL_D"]
}
RANGES = {
0.01: ps6000.PS6000_RANGE["PS6000A_10MV"],
0.02: ps6000.PS6000_RANGE["PS6000_20MV"],
0.05: ps6000.PS6000_RANGE["PS6000_50MV"],
0.10: ps6000.PS6000_RANGE["PS6000_100MV"],
0.20: ps6000.PS6000_RANGE["PS6000_200MV"],
0.50: ps6000.PS6000_RANGE["PS6000_500MV"],
1.00: ps6000.PS6000_RANGE["PS6000_1V"],
2.00: ps6000.PS6000_RANGE["PS6000_2V"],
5.00: ps6000.PS6000_RANGE["PS6000_5V"],
10.0: ps6000.PS6000_RANGE["PS6000_10V"],
20.0: ps6000.PS6000_RANGE["PS6000_20V"],
50.0: ps6000.PS6000_RANGE["PS6000_50V"]
}
MAX_ADC_VALUE = 32512
MIN_ADC_VALUE = -32512
COUPLING = {
"AC": ps6000.PS6000_COUPLING["PS6000_AC"],
"DC": ps6000.PS6000_COUPLING["PS6000_DC_1M"]
}
def open(self):
assert_pico_ok(ps6000.ps6000OpenUnit(ctypes.byref(self.handle), None))
def set_channel(self, channel: str, enabled: bool, coupling: str, range: float):
assert_pico_ok(ps6000.ps6000SetChannel(self.handle, self.CHANNELS[channel], enabled,
self.COUPLING[coupling], self.RANGES[range], 0,
ps6000.PS6000_BANDWIDTH_LIMITER["PS6000_BW_FULL"]))
def set_buffer(self, channel: str, enable: bool):
if self.samples is None:
raise ValueError
if enable:
if channel in self.buffers:
del self.buffers[channel]
buffer = (ctypes.c_int16 * self.samples)()
assert_pico_ok(
ps6000.ps6000SetDataBuffer(self.handle, self.CHANNELS[channel],
ctypes.byref(buffer),
self.samples, 0))
self.buffers[channel] = buffer
else:
assert_pico_ok(
ps6000.ps6000SetDataBuffer(self.handle, self.CHANNELS[channel],
None,
self.samples, 0))
del self.buffers[channel]
def set_frequency(self, frequency: int, samples: int):
return self._set_freq(frequency, samples, 3.2e-9, 4, 5_000_000_000, 156_250_000, 4)
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