The Circadian Rave System: An Affordable, Open-Source, and Easy-to-Build System for Any Light-Based Experiments.

Precise control of lighting has broad applications in all biological sciences, but none more so than in circadian research. Life on Earth has evolved circadian clocks that are endogenous regulators of physiology and behavior that entrain to the 24-h solar day. To study the clock, researchers rely on experimental manipulation of either light or temperature to entrain circadian rhythms. Most laboratories currently use either commercially available or in-house-built lighting equipment to either mimic or disrupt natural day and night cycling. These systems offer limited programmability and precision, lack standardization, and, in some instances, affordability. To address these issues, we have developed the Circadian Rave System, a bespoke software and hardware package that allows the precise control of multiple independent light boxes. We have made the software open source, along with detailed hardware build guides, with the aim that future research can be standardized through the use of this system. To demonstrate the functionality of this system and its utility in circadian experiments, we measured longevity and activity of Drosophila in various light paradigms to show circadian synchronization and disruption through light manipulation. In conclusion, we have developed a standardized, scalable, and affordable lighting system that can be built in-house by any researcher with minimal prior knowledge in electronics or programming.