Soil Sentry Dashboard

Project Overview

The Soil Sentry was born out of a practical need: I had to leave my plants unattended for two months while on vacation. Instead of hoping they would survive, I built a small-scale irrigation system that could monitor and water them automatically. The system allows multiple plants with different water needs to be managed at once, while also tracking the water reservoir levels in real time.

Estimated Time

Setting everything up took around 30 hours in total to calibrate the sensors, develope the code, setup the server side code, design and print the reservoir mount.

Project Objective

Most at-home watering kits only measure soil moisture and then water everything the same way. That doesn’t work well if you have different plant species with different needs. Soil Sentry makes it possible to define custom plant profiles and water accordingly, reducing waste while keeping each plant healthy.

The Setup

IDE

Thonny for the microcontroller code (MicroPython), and VS Code for the server and dashboard code.

Raspberry Pi Pico W Setup

I flashed the Pico W with the MicroPython firmware, configured it with Thonny, and then used it as the controller for the system.

The circuit connected the Pico, moisture sensors, ultrasonic sensor, relay, pumps, and power supply together. Getting the wiring clean and reliable was crucial for consistent readings and operation.

Wiring Diagram

Platform for Data Transmission

Sensor data was sent in JSON format via HTTP to a local server, which also powered the dashboard interface. This setup allowed me to visualize data in real time and check on the plants remotely.

Interesting Challenge

One of the most fun parts of the project was using the ultrasonic sensor to track reservoir levels. It’s not something you’d immediately think of for measuring water, but with the right calibration, it worked surprisingly well. Watching the dashboard update with live reservoir percentages was very satisfying.

Ultra Sonic Sensor Mount

Final Look

The final dashboard shows the water reservoir level, the different plant profiles plus the hourly and week plant water level graph.

See the dashboard in action on Youtube here.

Super Secret Version 2

Since creating this my plant collection has significantly expanded and with new plants come new needs (well not NEEDS but rather nice to haves). This means refactoring how the water is dispensed, new sensors for humidity monitoring and dispensing, posibbly intergration of remote controlled full spectrum LEDs, solenoid valves, better soil sensors galore and an independent monitor display. Its going to be such a fun journey