Transition selection
gateway
between user a object
Full color
light sensor
SPOT AND SET SYSTEM
A. System Architecture and Implementation As shown in Fig. 1, the proposed system consists of four parts: LED units, LED controllers, a gateway module, and a user interface (UI). The modules except for the UI exist on the object side to be decorated. A user sends control commands to a gateway module via WiFi to deliver the commands to a dedicated LED controller to change the lighting pattern. Based on the proposed two-step interaction method, the primary requirement is that each LED be capable of recognizing that it is spotted. So, an ambient light sensor is coupled with an LED. Once the light sensor detects that the LED is selected based on a certain brightness threshold, the corresponding LED is judged as “selected” and starts blinking in white as feedback to the user. If this process fails, the user can retry the spotting
process so that the light sensor can detect the backside light of the smartphone. After successful selection, the user sets a lighting pattern through his/her Android-based smartphone’s UI. The LED controller and gateway module are realized by
Arduino UNO, in which an Ethernet shield is stacked on the gateway module. A photoresistor and a full-color LED are utilized in the LED unit.
the
usability was implied through a user study.