Rain Alarm
Sound a buzzer the moment rain lands on the sensor pad.
Overview
The bare board exposes interdigitated copper traces. Rain drops bridge them, the analog reading collapses and the board triggers the alarm.
Build Steps
Wire the pad
VCC, GND and the analog output to A0; leave the bare board flat and exposed where rain will reach it.
Learn the dry value
Read A0 dry and wet to pick a threshold between the two readings.
Trigger the alarm
When the reading crosses the threshold for a few consecutive samples, switch on the buzzer and LED.
Mount it outdoors
Angle the pad so water runs off, keep the electronics box dry and use a longer ribbon cable if needed.
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