Raspberry Pi Watering System Keeps Plants Alive During an Extended Absence

Keeping plants alive is difficult, even under ideal conditions. Unlike a pet, your plants don’t whine when they want water. It’s up to you to remember to water them on the proper schedule. Too little water and they die. Too much water and they die. If you’re going on vacation or a long business trip, that becomes even more difficult. Redditor Peppeatta found themselves in that situation, and used a Raspberry Pi to build an automated watering system to keep their prized chili peppers alive during their absence.

There are many products on the market that you can purchase to automatically water your plants, and they’re actually surprisingly affordable. But a custom system like this one will give you the ability to add functionality and expand the capability as you see fit. This particular system can be set to water the plants on any arbitrary schedule, monitors moisture in the soil, and can send status reports via email to keep Peppeatta up to date on how everything is going. They also plan to integrate a Telegram bot in the future, which would let them send watering commands, see real time statistics, and receive notifications.

This system was built using a Raspberry Pi and an Arduino Uno. The Arduino is able to monitor one plant’s soil with a moisture sensor. The Raspberry Pi controls the water pump via a relay module. The water pump just sits in a large container of water and turns on when the when the relay is activated through the Raspberry Pi’s GPIO pins. Cron job schedules are used to check the soil moisture every 20 minutes and to delivery 40 seconds of water every two days. With the plants near a window in sunlight, this watering system should be enough to keep them alive and healthy for quite a while.