The GBE device is a tabletop growth chamber similar to experimental gardens on the International Space Station. It can accommodate many kinds of leafy green vegetables and herbs, along with some root vegetables and fruiting crops.
Plants grow in pots, usually six at a time, within a tray inside the growth chamber. The tray holds water, while an LED panel and fan provide light and air flow. When the GBE System is plugged in and switched on, the control circuit atop the LED panel operates the LEDs and fan automatically.
The control circuit is programmable. You can set the night/day timing (photoperiod), the balance and intensity of red, green, blue, and white LEDs ("light recipe"), and the fan speed. This programmability makes it possible to run experiments under a wide range of conditions.
By connecting sensors to the control circuit, it is also possible to measure environmental conditions, including temperature and humidity, inside the growth chamber. Sensor data and other measurements, including power usage and fan RPMs, are stored as log files within the control circuit. With built-in wifi, the control circuit can send data continuously to the GBE Cloud Server.
The control circuit is built around a Raspberry Pi Pico W microcontroller, a tiny single-board computer that runs simple programs. The Pico can be programmed in Python or C/C++ using development software that runs on Mac, PC, and Linux.
We programmed the Raspberry Pi Pico W with MicroPython, a lightweight version of the Python programming language optimized for the low-powered CPUs and limited memory of microcontrollers. There are excellent online resources available to help you learn to code in MicroPython.
