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