PiPonics is a full-stack web server for hydro/aero/aquaponics monitoring and control, consisting of a Raspberry Pi 4B connected to an STM32L432KC Nucleo Board via UART. The *ponics system is defined in a single configuration file config.json.
The goal of this system was to develop a framework for remote monitoring and control that can be configured via a single configuration file. Unfortunately the usage of an MCU board results in some repeated configuration steps between the Pi and STM32 (i.e. mapping sensor IDs). Therefore an overview of the tools and services used for this project are provided below in case they can be reused in other applications.
The web server is implemented as a series of Docker containers, orchestrated with docker-compose. They are described here:
- db-init: Parses
config.jsonand generates a database initialization SQL script for storing sensor readings and metadata. Automatically gets loaded into db's init directory at startup. - config-init: Parses and adds some extra fields to
config.json, such as UUIDs to all entities. - db: A PostgreSQL server for storing sensor readings.
- backend: Bulk of processing done here. Hosts a Flask API server for sensor data/actuator commands and communicates with the STM32 via pyserial.
- frontend: Angular web application running on Node.js. Uses Bootstrap's Grid System and the popular Chart.js library for displaying sensor readings. NOTE: PiPonics was deisgned for usage within a local network and currently uses a development server for hosting the frontend application. Serve publicly at your own risk.
The STM32L432KC Nucleo Board is used as an I/O board for interfacing with sensors and actuators. It is implemented as a FreeRTOS application with two tasks:
- ReceiveUART: Waits for UART command frame from Pi (typically request for sensor reading or actuator drive) and sends response.
- DetectOverflow: Detects if the grow bed has flooded via a float switch. If triggered, grow bed water pump is automatically shut off and a piezo buzzer starts beeping to alert user.
This project was the inspiration for ponics32, an all-in-one *ponics management server based on the ESP32 microcontroller.