diff options
Diffstat (limited to 'pyecsca/sca')
| -rw-r--r-- | pyecsca/sca/scope/picoscope_sdk.py | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/pyecsca/sca/scope/picoscope_sdk.py b/pyecsca/sca/scope/picoscope_sdk.py index 68562b9..035e8c0 100644 --- a/pyecsca/sca/scope/picoscope_sdk.py +++ b/pyecsca/sca/scope/picoscope_sdk.py @@ -1,5 +1,6 @@ """Provides an oscilloscope class for PicoScope branded oscilloscopes using the official `picosdk-python-wrappers <https://github.com/picotech/picosdk-python-wrappers>`_.""" +import warnings import ctypes from math import log2, floor from time import time_ns, sleep @@ -189,39 +190,47 @@ class PicoScopeSdk(Scope): # pragma: no cover tb = min(floor(log2(low_freq) - log2(frequency)), timebase_bound) actual_frequency = low_freq // 2**tb max_samples = ctypes.c_int32() + interval = 0.0 if tb <= timebase_bound: - interval_nanoseconds = ctypes.c_float() + interval_nano_float = ctypes.c_float() assert_pico_ok( self._dispatch_call( "GetTimebase2", self.handle, tb, samples, - ctypes.byref(interval_nanoseconds), + ctypes.byref(interval_nano_float), 0, ctypes.byref(max_samples), 0, ) ) + interval = interval_nano_float.value else: - interval_nanoseconds = ctypes.c_int32() + interval_nano_int = ctypes.c_int32() assert_pico_ok( self._dispatch_call( "GetTimebase", self.handle, tb, samples, - ctypes.byref(interval_nanoseconds), + ctypes.byref(interval_nano_int), 0, ctypes.byref(max_samples), 0, ) ) + interval = interval_nano_int.value if max_samples.value < samples: pretrig = max_samples.value * (pretrig // samples) posttrig = max_samples.value - pretrig samples = max_samples.value - # TODO: actual_frequency and "1e9 / interval_nanoseconds.value" should be close + interval_diff = actual_frequency / (1e9 / interval) + if interval_diff > 1.1 or interval_diff < 0.9: + warnings.warn("Reported frequency differs from computed.") + freq_diff = actual_frequency / frequency + if freq_diff > 1.1 or freq_diff < 0.9: + warnings.warn("Requested frequency (significantly) differs from provided.") self.frequency = actual_frequency self.samples = samples self.pretrig = pretrig |