This project provides an open-hardware, Wi-Fi-enabled single-board computer (PCBA) designed to automate mid-size hydroponic systems. It offers extensive I/O for managing pumps, valves, and sensors (pH, EC, temperature, humidity, strain gauges), targeting hobbyists and researchers who need precise environmental control for plant cultivation or water treatment. The system allows for remote monitoring and control via HTTP requests.

How It Works

The core of the system is an ESP32 microcontroller running custom firmware. This firmware exposes an HTTP API for controlling actuators (12V outputs for pumps, valves) and reading sensor data. It features direct interfaces for pH and EC probes, utilizing specialized analog front-ends with driven shields for high impedance measurements and AC coupling to prevent polarization. Dosing pumps are controlled via PWM-derived analog voltage, with optional intermittent operation for precise low-rate dosing.

Quick Start & Requirements

• Firmware Installation: Requires Espressif IDF framework. Build and flash firmware using idf.py flash.
• Hardware: Requires assembly of a custom PCB and components (estimated ~$90).
• Networking: ESP32 acts as a Wi-Fi client; SSID/password must be compiled into firmware.
• Control: HTTP requests from any network-capable device.
• Documentation: Board README

Highlighted Details

• Extensive I/O: 8x 1A, 6x 0.5A (with current monitoring), 2x 0.25A (analog voltage control) 12V outputs; 2x pH, 2x EC, 2x resistive, 2x temp/humidity, 2x strain gauge inputs.
• Analog Front-ends: High-impedance electrometer op-amps for pH, AC-coupled EC measurement, and driven shields to mitigate leakage.
• Dosing Pump Control: Programmable DC voltage output with configurable intermittent operation for precise low-flow dosing.
• Current Monitoring: Integrated current sensing on pump outputs for load monitoring and potential volume estimation.

Maintenance & Community

• Primarily a personal project with limited public community engagement noted.
• Future development ideas include integration with existing control software and on-device standalone logic.
• GitHub issues are the primary channel for discussion.

Licensing & Compatibility

• Firmware: GPLv3 or later.
• Hardware: Open hardware; allows building and selling, provided loaded software is free (OSI-approved) and not used to enable non-free software. No false claims of ownership.

Limitations & Caveats

• Hardware is not commercially available assembled; requires DIY assembly.
• Firmware requires compilation and flashing via ESP-IDF. Wi-Fi credentials must be compiled in.
• No built-in security features; intended for use behind a firewall.
• No warranty provided; use in life-critical applications is strongly discouraged.