DIY Soil Moisture Sensor

🌱 For This Earth Day, I built something small that does something meaningful.

For the #EarthDaywithSeeed community campaign, I created a battery-powered smart soil moisture monitor using the Seeed Studio XIAO ESP32-C3 and a capacitive moisture sensor — all powered by a tiny 250mAh LiPo.

Here's what went into it:

The MCU wakes every 10 minutes, collects the data, and sends it to the web server — then goes back into deep sleep mode.

Without sleep mode, the project runs for around 2.5 hours. With deep sleep enabled, the device can run for 5–7 days at a 10-minute interval.

For the enclosure, I designed a custom one to fit the MCU and battery — but later decided to get a little creative and used the enclosure that came with the XIAO boards.

I used a capacitive soil moisture sensor for more reliable, corrosion-resistant readings compared to resistive sensors (I had a bad experience with those previously). It gives accurate moisture readings without degrading over time.

For the web server and dashboard UI, I used Next.js.

Plants can't tell you when they're thirsty. But now, they don't have to.

Happy Earth Day 🌍