Read the YL-99 impact-switch module with a defined pull-up and verify its polarity and board pinout before wiring.
Read the KY-031 as a mechanical impact switch and debounce its short, bouncing pulses in software.
Measure low-pulse occupancy from a DSM501A to follow dust trends, without presenting the result as a regulatory PM2.5 measurement.
Estimate conductivity-derived TDS trends with temperature compensation and calibration; TDS alone cannot determine whether water is safe to drink.