These smart sensors detect water leaks by measuring resistance between two contacts (two M3 bolts). If a water leak is detected:

• Local alarm goes off (loud piezo buzzer signals, blinking red LED)
• All other identical water sensors throughout the house also sound alarm (loud piezo buzzer signals, number of red LED flashes in a sequence = sensor ID of the sensor were the leak was detected). For this, WiFi and MQTT server are required
• Alarm is displayed in OpenHAB browser (or app) interface (on smart phones etc.). WiFi, MQTT server, and OpenHAB server are required.
• Email is sent to a predefined email address. WiFi, MQTT server, and OpenHAB server with the Mail action add-on are required.

After alarm goes off, pressing the button on any sensor will silence all alarms for predefined interval (30s by default). Only buzzer becomes silent, but the rest works as usual (water detection, red LED alarm, OpenHAB notifications, emails etc). After the predefined quiet time, if the water leak is still present, alarm again goes off on all sensors.

If water leak is no longer detected, alarm is canceled on all sensors.

Green LED turns on when WiFi connection is established. If no MQTT connection can be established, green LED slowly flashes.

If water sensor is shorted, piezo and red LED are chirping every 5s.

The sensor is powered via micro USB 5V power.

Total cost for the parts is ~6$.

Full details (schematics, code etc): https://pulsar124.fandom.com/wiki/Smart_water_leak_sensor

The version 2 of the top and bottom parts of the enclosure are for the case when you use M3 bolts and nuts (not screws) to connect the two parts.

Anet AM8

No

No

0.1

100%

Minimum supports might be needed when printing the top cover, for the micro USB hole.