Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

This paper discusses the development of a distributed control system for low-pressure plant growth chambers using microcontrollers, a computer, and a process gas chromatograph. Variables that are critical to supporting long-term, manned exploration of space and may affect plant growth and development are monitored and controlled. The system incorporates six low pressure growth chambers, each controlled by a single PIC16F877 microcontroller. Data from the microcontrollers are routed through a PC running LabVIEW, which returns setpoints for total pressure and oxygen, carbon dioxide, and nitrogen concentration to the microcontrollers. The gas composition is monitored by a process gas chromatograph, which delivers data to the PC via the MODBUS protocol. Temperature control and lighting are supplied by an independent plant growth room, which contains the six low pressure chambers.