Plant Watering Alarm (Chirp)

From the shop's description

The Chirp! Plant Watering Alarm is a new device from wemakethings that helps extend the life of your plant by reminding you to water it. This plant water alarm is essentialy a moisture sensor with built-in coin battery and sound alarm. Chirp is a plant watering alarm - as simple as that. You put it into the soil near a plant and it emits a tiny chirp (sharp sound) when the soil is dry, reminding you to water the plant. Alternatively, Chirp can work as an I2C soil moisture sensor. Features Standalone plant watering alarm C Can be used as I2C moisture sensor Built-in coin battery holder Plant Watering Alarm user manual