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 3000rpm for 30 seconds. The film on the substrate was then heated at 850(o)C for 15hours. 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 0m, 0.5m, 1m, 1.5m, 2m, 2.5m, and 3m at angles of 0(0), 30(0), 45(0) and 60(0) (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.