Configuration 1: Basic fire and flood alarm

Subsystems

Microcontroller

Battery System (non rechargeable)

Thermistor Circuit

Moisture/Contact Sensor

Siren

Push-button

Approximate build cost

US$8.50, ZAR128

Operation

The moisture spike is pushed into the ground or placed in a position where it will get wet when flooding occurs.

The unit itself must be mounted near the area where fire is to be used but not directly above normal cooking areas.

The siren will sound when a flood or a fire situation is detected.

In the case of a fire a red light will also be illuminated.

To stop the siren, press the button on the edge of the unit.

The moisture probe may need to be dried off to prevent the siren from going off again if it is wet.

Because the system consumes very little power a non-rechargeable battery will suffice for many years of maintenance-free operation. Depending which battery option is chosen and how often the alarm is triggered a lifespan of ten years may be realised.