6cac2d275d
Implemented according to API docs in a parent comment. Adds new multi_extmod/machine_can_* tests which pass when testing between NUCLEO_G474RE, NUCLEO_H723ZG and PYBDV11. This work was mostly funded through GitHub Sponsors. Signed-off-by: Angus Gratton <angus@redyak.com.au>
61 lines
2.3 KiB
Python
61 lines
2.3 KiB
Python
# Test machine.CAN timings results
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#
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# Single device test, assumes no connections to the CAN pins
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try:
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from machine import CAN
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except ImportError:
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print("SKIP")
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raise SystemExit
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import unittest
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from target_wiring import can_args, can_kwargs
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class TestTimings(unittest.TestCase):
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def test_bitrate(self):
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for bitrate in (125_000, 250_000, 500_000, 1_000_000):
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can = CAN(*can_args, bitrate=bitrate, **can_kwargs)
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print(can)
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timings = can.get_timings()
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print(timings)
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# Actual bitrate may not be exactly equal to requested rate
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self.assertAlmostEqual(timings[0], bitrate, delta=1_000)
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can.deinit()
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def test_sample_point(self):
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# Verify that tseg1 and tseg2 are set correctly from the sample_point argument
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for sample_point in (66, 75, 95):
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can = CAN(*can_args, bitrate=500_000, sample_point=sample_point, **can_kwargs)
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_bitrate, _sjw, tseg1, tseg2, _fd, _port = can.get_timings()
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print(f"sample_point={sample_point}, tseg1={tseg1}, tseg2={tseg2}")
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self.assertAlmostEqual(sample_point / 100, tseg1 / (tseg1 + tseg2), delta=0.05)
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can.deinit()
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def test_tseg_args(self):
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# Verify that tseg1 and tseg2 are set correctly and sample_point is ignored if these are provided
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for tseg1, tseg2 in ((5, 2), (16, 8), (16, 5), (15, 5)):
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print(f"tseg1={tseg1} tseg2={tseg2}")
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can = CAN(
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*can_args, bitrate=250_000, tseg1=tseg1, tseg2=tseg2, sample_point=99, **can_kwargs
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)
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bitrate, _sjw, ret_tseg1, ret_tseg2, _fd, _port = can.get_timings()
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self.assertEqual(ret_tseg1, tseg1)
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self.assertEqual(ret_tseg2, tseg2)
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def test_invalid_timing_args(self):
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# Test various kwargs out of their allowed value ranges
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with self.assertRaises(ValueError):
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CAN(*can_args, bitrate=250_000, tseg1=55, **can_kwargs)
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with self.assertRaises(ValueError):
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CAN(*can_args, bitrate=500_000, tseg2=9, **can_kwargs)
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with self.assertRaises(ValueError):
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CAN(*can_args, bitrate=-1, **can_kwargs)
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with self.assertRaises(ValueError):
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CAN(*can_args, bitrate=500_000, sample_point=101, **can_kwargs)
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if __name__ == "__main__":
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unittest.main()
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