Configuration 5: Fire and flood alarm with WiFi communication and solar light

Subsystems

Microcontroller

Battery System (rechargeable)

Thermistor Circuit

Moisture/Contact Sensor

Siren

Push-button

WiFi Module

Dimmable LED

Indicator LEDs

Approximate build cost

US$17, ZAR255

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.

Ideally the unit should be positioned so that the light is also in a useful area.

If a solar panel is used, it must be put on the roof facing upwards (the wire is connected to the bottom of the panel). Glue the panel down securely to prevent wind damage or theft. Make sure that there are as few shadows on the solar panel as possible.

Alternatively, if mains power is available the unit can be powered from a cellphone charger with a micro USB cable.

Press the button on the edge of the unit to turn the light on or off.

When the sun is shining or the unit is plugged in, the battery will charge up so that the light can be used at night.

When the battery is charging a small white light will be lit. A green light will indicate that the battery is fully charged.

The light can be used even if the battery is not entirely full.

The light is about as bright as ten normal candles. It will typically run for several hours a day even in winter, and more in summer.

When the battery is depleted the light will turn off and it may be turned on again after the battery is recharged.

The siren will sound and the unit will send out a message over the WiFi network to which it is connected 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.

WiFi networks need to be configured with a network name and password. In addition, the email address to which alerts must be sent is needed. These are entered by holding the button in for ten seconds. A WiFi network called Sigthsense will then be activated. Logging into this network will allow a user to set up credentials and an email address for alerts.

It is suggested that the WiFi connection be tested by dipping the moisture probe into water.