invilab Handles Electronic Circuit Design and Control App Development for Prop 'dejavu' in Movie 'Mystery Arena'

invilab K.K. (Headquarters: Tokorozawa, Saitama; CEO/CTO: Ryota Wakabayashi) announced that it handled the internal electronic circuit design and control application development for the prop 'dejavu', which appears in the movie 'Mystery Arena' (Production: Amazon MGM Studios, Distribution: Shochiku), released nationwide on Friday, May 22, 2026. The 'dejavu' features a control board equipped with a battery, LED, and communication capabilities, designed to allow remote adjustment of LED brightness, color, and blinking via a dedicated app. The exterior was crafted by INAC K.K.

Internal Electronic Circuit Design

The design required stable operation of lighting, communication, and power functions within a limited space of approximately 4.5cm in height and 1-2cm in width. Although coin cell batteries were initially considered, a rechargeable battery was chosen to ensure the necessary brightness for filming. The design successfully implemented the control board, battery, and charging connector within the small housing while optimizing for stable power consumption. Given the long periods actors might wear the device, energy-saving controls were incorporated to reduce power consumption during idle or standby modes.

Control App Development

The app requirement was to enable remote operation of LED brightness, color, and blinking patterns. For quick operation on set, brightness adjustment supports both preset stages and manual slider control. Color selection includes standard Red, Green, and Blue buttons alongside full RGB value adjustment. Five blinking patterns can also be set. To address the radio-heavy environment of a film set, the app features a signal strength meter, battery level monitor, and device internal temperature monitoring. A safety feature automatically shifts the LEDs to a power-saving mode if the connection is lost. Throughout the development phase, functions were refined based on real-time feedback from the set, ensuring both the app and device firmware were optimized for practical use.

Exterior Fabrication (by INAC K.K.)

INAC K.K. was responsible for the master model making, casting, and painting. The 'master' unit (gold) features a half-gold vapor deposition, while the 'slave' units (white) have a diffused milky-white finish. The bridge connector uses elastomer rubber casting to provide both flexibility and a realistic fit.