def testToneCreate(self):
"""create a Dds with a DdsTone instance"""
self.assertIsInstance(self.dev, iio.Device, 'ok')
tone = pluto_dds.DdsTone(self.dev, 'F1')
self.assertIsInstance(tone, pluto_dds.DdsTone,
'ddsTone instance created')
tone.setFreq(1)
npt.assert_almost_equal(tone.getFreq(),
1.0,
decimal=4,
err_msg='initial frequency value')
tone.setPhase(0)
npt.assert_almost_equal(tone.getPhase(),
0.0,
decimal=4,
err_msg='initial phase value')
npt.assert_almost_equal(tone.getPhase('Q'),
270.0,
decimal=4,
err_msg='initial phase value')
tone.setAmplitude(0.5)
npt.assert_almost_equal(tone.getAmplitude(),
0.5,
decimal=4,
err_msg='initial amplitude value')
def testSetPhase(self):
"""confirm the relative I/Q phases for +/- frequencies"""
dds = pluto_dds.Dds(self.dev)
tone = pluto_dds.DdsTone(self.dev, 'F1')
tone.frequency = 1
tone.phase = 180 # set phase mid way
i_phase = tone.getPhase()
q_phase = tone.getPhase('Q')
def testPhaseNormalisation(self):
"""confirm phase values restricted to 0 <= phi <= 360"""
tone = pluto_dds.DdsTone(self.dev, 'F1')
tone.phase = -10
npt.assert_almost_equal(tone.phase,
350,
decimal=2,
err_msg='phase norm -10 -> 350 degs')
def testWithinFs(self):
"""confirm freq values are within +/- half fs"""
tone = pluto_dds.DdsTone(self.dev, 'F1')
tone.amplitude = 0.5
tone.frequency = 0.5
fs = tone.getSamplingFreq()
with self.assertRaises(ValueError,
msg='when setting f outside +/-fs/2'):
tone.setFreq(fs)
def testPosNegFreq(self):
"""confirm the relative I/Q phases for +/- frequencies"""
tone = pluto_dds.DdsTone(self.dev, 'F1')
fs = tone.getSamplingFreq()
tone.frequency = fs/8
tone.phase = 180 # set phase mid way
i_phase = tone.getPhase()
q_phase = tone.getPhase('Q')
tone.frequency = -fs/4
self.assertEqual(i_phase, tone.getPhase(),
'I phase equal for +/- freq')
self.assertEqual(abs(q_phase - tone.getPhase('Q')), 180,
'Q phase opposite for +/- freq')
def testOnOff(self):
"""confirm amplitude settings are preserved from off to on"""
tone = pluto_dds.DdsTone(self.dev, 'F1')
tone.amplitude = 0.5 # some initial setting
self.assertEqual(tone.amplitude, 0.5, "setting attribute ok")
tone.i_ch.attrs['raw'].value = '0'
self.assertEqual(tone.amplitude, 0.5, "off preserves amplitude")
tone.i_ch.attrs['raw'].value = '1'
self.assertEqual(tone.amplitude, 0.5, "return to previous setting")
tone.i_ch.attrs['raw'].value = '0'
tone.amplitude = 0.1
tone.i_ch.attrs['raw'].value = '1'
npt.assert_almost_equal(tone.amplitude, 0.1, decimal=4,
err_msg="ok setting change even when off")
def testOnOff(self):
"""confirm amplitude settings are preserved from off to on"""
tone = pluto_dds.DdsTone(self.dev, 'F1')
tone.amplitude = 0.5 # some initial setting
self.assertEqual(tone.amplitude, 0.5, "setting attribute ok")
tone.state(OFF)
self.assertEqual(tone.amplitude, 0.0, "off make amplitude 0")
tone.state(ON)
self.assertEqual(tone.amplitude, 0.5, "return to previous setting")
tone.state(OFF)
tone.amplitude = 0.1
tone.state(ON)
npt.assert_almost_equal(tone.amplitude,
0.1,
decimal=4,
err_msg="ok setting change even when off")
def testProperties(self):
"""confirm read and write to properties"""
tone = pluto_dds.DdsTone(self.dev, 'F1')
fs = tone.getSamplingFreq()
tone.frequency = -fs/4
npt.assert_almost_equal(tone.frequency, -fs/4, decimal=3,
err_msg='using frequency property')
tone.phase = 20
npt.assert_almost_equal(tone.phase, 20.0, decimal=3,
err_msg='using phase property')
tone.amplitude = 0.2
npt.assert_almost_equal(tone.amplitude, 0.2, decimal=3,
err_msg='using amplitude property')
with self.assertRaises(ValueError,
msg='value set out of 0 .. 1 range'):
tone.amplitude = 10