Hydroponix: Smart Hydroponic IoT System

The Problem

Hydroponic growing demands tight control over water pH, nutrient concentration, humidity, light, and temperature — simultaneously, 24 hours a day. Manual checks are labour-intensive and miss the variance that happens between visits. The client needed an automated system that could control all parameters remotely and scale from a single growing bed to a commercial facility.

What We Built

A modular IoT system with two hardware layers that communicate over a local network:

Sensor/control modules — STM32-based nodes mounted directly on each growing bed. Each module controls the irrigation pump, monitors water pH and TDS (Total Dissolved Solids), measures humidity, and doses fertiliser based on sensor readings. One module per bed; add beds without reconfiguring the rest.

Central node — ESP32-based hub that polls all modules, aggregates data, stores history, and runs the control logic for illumination, temperature, and ventilation across the grow room. A browser-based interface gives operators real-time visibility and manual override from any device on the network.

Technical Stack

• Module MCU: STM32 — handles per-bed sensors and actuators (pump, dosing valve, humidity sensor)
• Central node: ESP32 — WiFi connectivity, data aggregation, graphing, control logic
• Sensors: pH probe, TDS meter, humidity sensor, temperature sensor, light intensity
• Actuators: irrigation pump relay, fertiliser dosing pump, ventilation fan
• Interface: browser-based dashboard — live readings, historical charts, threshold configuration
• Power: 220V mains; no battery requirement given fixed installation

What the System Controls

• Irrigation — waters on schedule and on threshold, not a fixed timer. If soil sensors read dry ahead of schedule, watering triggers early.
• Nutrient dosing — TDS and pH readings drive automatic fertiliser additions. Targets configurable per crop type and growth stage.
• Climate — temperature and humidity within set ranges; ventilation fans activate when thresholds exceed limits.
• Lighting — photoperiod scheduling per growing zone; intensity monitoring with alert on lamp failure.

Architecture: Modular by Design

The modular structure was a deliberate requirement: the client needed to expand from 4 beds to 20+ without rewiring. Each STM32 module is self-contained — it runs its own control loop for the bed it’s attached to and reports upstream to the ESP32 hub. Adding capacity means plugging in another module. The central node discovers it automatically.

Need precision agriculture or hydroponic automation software? CimpleO’s IoT engineering team builds sensor networks, control systems, and farm management platforms from firmware to dashboard. Get in touch.