The suggestions for hardware to control your GutterGrow are based upon:
Low cost (say less than £20)
Wide availability of hardware parts and connectors (UK and international)
Strong hardware and software support networks and tools
Utility construction - simple DIY assembly and connection of readily available parts
Control of system from many types of client device over wifi
Feedback and alerts to many types of client device over wifi and/or bluetooth
Safe low power and/or solar powered system (12v or 5v DC supply for system)
Based on the above it is suggested that the microcontrollers from Espressif and the Raspberry Pi Foundation can provide suitable hardware meeting all requirements.
The proposals below are based on the ESP32 series from Espressif, the Raspberry Pi Pico series from the Pi Foundation along with readily available low cost sensors and actuators.
However the software proposed in Project Five is based on micropython running on a compatible microcontroller and therefore it should be relatively easy to port to other microcontrollers or SBCs (Single Board Computers) capable of running micropython.
The first important task is the control of the irrigation and nutrient flow through the GutterGrow system. This task is simplified by the cascading of the gutters so that irrigation and nutrient flow can be introduced as 'flow needed' at the highest level of a GutterGrow system and then detected as 'flow complete' at the lowest level.
The hardware system can be implemented with the following parts:
12v or 5v DC power source (battery or DC adaptor)
5v or3.3v relay for switching 12v DC
12v DC valve (if controlling mains or other pressurised water supply) or
12v DC pump (if pumping required from water tank or other unpressurised store)
Non conductive substrate for mounting parts
Waterproof enclosure if outdoor operation required
Irrigation tubing and drippers compatible with chosen pump or valve