Fascination with Firefly Synchronization
The captivating phenomenon of visual patterns, whether they occur naturally or are created by humans, often evokes a sense of wonder. One of the mesmerizing natural occurrences is the synchronization of hundreds or even thousands of fireflies. Initially, these fireflies flash their lights randomly, but over time, they start synchronizing their flashes, influenced by one another, creating a mesmerizing display of light patterns. Inspired by this phenomenon, the author devised a circuit, presented here for Elektor readers. This version of the circuit utilizes an ATtiny13 microcontroller and a single RGB LED, designed to be both cost-effective and easy to construct in large quantities. Unlike real fireflies, the RGB firefly in this circuit does not move around; instead, it conveys its mood through different colors. When all is in perfect synchrony, the LED emits a relaxed and cool blue light.
Robotic Fireflies: Synchronizing Light Displays
If the robotic firefly detects flashes that are not synchronized, it enters an uncomfortable state, changing colors to green, yellow, and red. Each firefly operates independently, without following any pre-programmed patterns. When multiple fireflies interact, they form a self-organizing system, gaining strength and enjoyment in numbers. The behavior of each firefly is determined by its firmware, which responds to light levels measured by an SFH3310 phototransistor. Essentially, each firefly possesses a power value dictating its flashing behavior.
Behavior of Robotic Fireflies
Over time, the power value of each firefly increases. When this value reaches a specific limit, the firefly flashes, and the power resets to zero. If a firefly detects a nearby flash, it slightly boosts its power, causing it to flash a bit earlier than before. Through repeated interactions, all fireflies may eventually synchronize their flashes, demonstrating the concept of robotic swarming. The circuit comprises essential components: a microcontroller, light sensor, and RGB LED. The ATtiny13 microcontroller reads the voltage level from the sensor via a potential divider formed by the sensor and R4. The circuit requires a 5 V power supply, drawn from a rail formed by connecting firefly boards in a row using plug/socket pairs JP1 and JP2.
Choosing Optimal Components for Robotic Fireflies
Various photoresistors were tested, with the SFH3310 phototransistor proving superior due to its faster reaction time (~5 ms compared to ~50 ms for LDRs) and absence of a memory effect. The choice of light sensor is crucial, as it must align with human eye sensitivity (approximately 400 nm – 700 nm). Interested individuals can download the software for RGB Synchronizing Fireflies freely from the Elektor website. The software can be compiled and programmed into the ATtiny chip through ISP header K1. For those lacking a suitable programmer, a pre-programmed ATtiny13(V) chip can be ordered from Elektor.
Creating Clusters of Robotic Fireflies
The construction and application of these electronic creatures are extensively documented on the author’s website, featuring images and videos illustrating their usage. The website also provides information on acquiring kits for this innovative project, blurring the lines between technology and biology. www.elektor.com/100014  www.elektor.com/100013  www.elektor.com/100358  http://tinkerlog.com/2009/06/25/64- synchronizing-fireflies/  http://tinkerlog.com/howto/synchronizing-firefly-how-to/