22 lines
864 B
Plaintext
22 lines
864 B
Plaintext
ADC accuracy test
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This test checks that ADC readings match an expected value. It is
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done using two approaches:
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- DAC source: a board DAC pin is set to a known value, which is then
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read on an ADC one. If they match, the test passes.
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- Reference voltage: an ADC channel is read and compared to an expected
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value.
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For the DAC source, it is expected that DAC and ADC are connected. This
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can be indicated for twister runs by setting the fixture "dac_adc_loop".
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The test then sets DAC to half its resolution and reads the ADC to see
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if they match. Note that DAC and ADC are expected to generate/read
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voltage on the same range.
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In the reference voltage case, the ADC is expected to be connected to a
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known voltage reference, whose value is informed, in millivolts, at
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property "reference_mv" from "zephyr,user" node. The test reads the ADC
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to see if they match.
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