Application of lithium tantalate (LiTaO₃) films as light sensor to monitor the light status in the Arduino Uno based energy-saving automatic light prototype and passive infrared sensor

ABSTRACT

Growth of LiTaO₃ film on a type-p silicon substrate (100) was conducted using the Chemical Solution Deposition (CSD) and spin coating methods at a speed of 3000 rpm for 30 seconds. The film on the substrate was then heated at 850^oC for 15 hours. The resulting film was then characterized for its sensitivity value. The film was utilized as a light sensor to read changes in light intensity to monitor lighting status in an Arduino Uno-based energy-saving automatic light prototype. Previously, the output of the film in the form of an electrical voltage was strengthened using a voltage amplifying circuit (OP-Amp). The energy-saving automatic light prototype was manufactured in two conditions, an automatic condition (with assistance from an infrared passive sensor and real time clock) and a manual condition (with assistance from a GSM to control the lighting and LiTaO₃ film as a light sensor to monitor the lighting status). In the automatic condition, the assessment of the infrared passive sensor's sensitivity was conducted at distances of 0 m, 0.5 m, 1 m, 1.5 m, 2 m, 2.5 m, and 3 m at angles of 0⁰, 30⁰, 45⁰ and 60⁰ (the source of motion was human movements). The real time clock was used to regulate the infrared passive sensor activation time (7 a.m to 5 p.m Western Indonesia Time). In the manual condition, when entering manual time (outside the 7 a.m to 5 p.m Western Indonesia Time range), to be exact, the GSM would send a message containing the duration of the lighting usage and the cost of the lighting usage. Activation of the lighting was conducted by replying to the message with the code #1 to turn on the lighting and #0 to turn it off.

KEYWORDS:

• Lithium tantalate (LiTaO₃) film
• infrared passive sensor
• real time clock
• Arduino Uno
• GSM

Funding

This work was funded by International Research Collaboration and Scientific Publication under contract No. 011/SP2H/LT/DRPM/IV/2017. Ministry of Research, Technology, and Higher Education, Republic of Indonesia and USAID SHERA program through Centre for Development of Sustainable Region (CDSR).