def json(self):
return {
'version': self.version,
'time': self.time.isoformat(),
'timestamp': str(seconds_to_timestamp(self.time.timestamp())),
'product_name': 'Joulescope JS110',
'vendor_name': 'Jetperch LLC',
'subtype_name': 'Calibration',
'product': f'{self.product_id}.{self.vendor_id}.{self.subtype_id}',
'serial_number': self.serial_number,
'voltage': {
'offset': _np_list(self.voltage_offset),
'gain': _np_list(self.voltage_gain),
},
'current': {
'offset': _np_list(self.current_offset),
'gain': _np_list(self.current_gain),
},
}
def save(self, private_key=None):
"""Save calibration to bytes.
:param private_key: The private key used to sign the calibration.
None (default) does not sign the calibration.
The Joulescope software will display warnings if the calibration
is not signed using a valid key.
:return: The calibration as bytes.
"""
if isinstance(self.time, str):
self.time = dateutil.parser.parse(self.time)
fh = io.BytesIO()
dfw = datafile.DataFileWriter(fh)
if private_key is not None:
dfw.signature_start(private_key)
dfw.append_header(
timestamp=seconds_to_timestamp(self.time.timestamp()),
version=_version_str_to_u32(self.version),
product_id=self.product_id,
vendor_id=self.vendor_id,
subtype_id=self.subtype_id,
hardware_compatibility=0,
serial_number=binascii.unhexlify(self.serial_number),
)
self.current_offset = np.concatenate(
(self.current_offset[:7], [0.0, np.nan]))
self.current_gain = np.concatenate(
(self.current_gain[:7], [0.0, np.nan]))
if len(self.current_offset) != 9 or len(self.current_gain) != 9:
raise ValueError('Invalid length for current')
if len(self.voltage_offset) != 2 or len(self.voltage_gain) != 2:
raise ValueError('Invalid length for voltage')
cal = self.json()
dfw.append(datafile.TAG_DATA_JSON,
json.dumps(cal, allow_nan=True).encode('utf-8'))
if private_key is not None:
dfw.signature_end()
dfw.finalize()
return bytes(fh.getbuffer())
def test_conversion(self):
now = time.timestamp_now()
s = time.timestamp_to_seconds(now)
t = time.seconds_to_timestamp(s)
self.assertEqual(now, t)
def test_seconds_to_timestamp(self):
self.assertEqual(0, time.seconds_to_timestamp(time.EPOCH))