Keeping plants alive is easy if you’re diligent and never forget to check on your green friends. However, a little electronic help never hurts. To that end, [Narrow Studios] built a simple solar powered monitor to assist in plant maintenance, and it mostly does the job.
An ESP32-C3 development board serves as the brains of the operation. It’s set up with a capacitive soil moisture sensor, a great choice because they tend to last longer than other types. Power is courtesy of a small lithium-polymer battery and a solar panel, which keeps everything running off the juice from interior lighting alone.
SK6812 addressable LEDs are used to show current soil moisture status. To avoid excessively draining the batteries with the limited power available, a HCSR505 PIR motion sensor is used to only light the status LEDs if the device detects someone in the vicinity. There were some issues in the build.
The voltage regulator doesn’t supply enough current to enable the ESP32 to jump on WiFi, so soil dryness indication is via LED only. The solar setup is a little weak, too. Still, the project was a great learning experience and with a few mods, would be even more capable. We’ve featured some great plant monitors over the years, like this Hackaday Prize entry from 2023.