A microcontroller-based system for flexible oxygen control in laboratory experiments

Environmental control systems are important tools for experimental researchers studying animal-environment interactions. Commercial systems for measurement and regulation of environmental oxygen conditions are relatively expensive and can not always be adapted to varying experimental applications. Here, I present a low-cost and highly flexible oxygen control system using Arduino microcontrollers in combination with a commercial optical oxygen sensor. Hardware and software examples are provided for three different applications: single-setpoint, sequential, and long-term dissolved oxygen (DO) control. All tested control systems created the desired DO conditions with high accuracy and repeatability across trials. The resources provided shown here can be adapted and modified to be used in a variety of experimental contexts.