Fig. 2 (a) illustrates the setting flow of lighting patterns. One or more LEDs are selected as a target group by spotting with the backside light of a smartphone. Once the target is specified, a lighting pattern is selected. The lighting pattern of LEDs is divided into two types: independent blinking and combination blinking. In independent blinking, each LED blinks independently as the name suggests, while combination blinking indicates that a group of LEDs blink in a coordinated manner. Combination blinking can further be classified into three types: blinking alternately odd-numbered LEDs and
even-numbered LEDs, blinking in a spotted order, and turning on in a spotted order (and turning off after all LEDs turn on).