To install a water detector circuit, take a perforated board of about 2 inches by 4 inches and wind two coils of 22 AWG wire around it. Mount the sensor to the water alarm circuitry box using foam tape or silicone adhesive. To enable battery monitoring, connect the analog input pin to an output pin. The series diodes provide a reference voltage to make the voltage changes visible.
Use a surface acoustic wave resonator as a low-power transmitter, operable over a wide range of voltages. The wireless transmitter requires as much power as possible to create a reliable signal, which can be generated by coding the alarm at just above 4 volts. On the receiver circuit, use one connector to monitor voltage strength and the other to feed an input on a home alarm system.
The short antenna should operate on a 433-megahertz frequency; 916.5 megahertz is also acceptable. It is important to have a battery monitor when building a battery-powered alarm circuit, but if the reference voltage comes from the battery itself, the reference drains as the battery does. This results in no voltage reference being registered. Solve this by connecting the input and output pins; this creates a low current that drops the voltage across each diode.