Measuring the Flashing Time Interval of LED Lights in Toys

A new Zigbee-based device for measuring visual reaction time in sport activities

“…The high-speed camera used to film the flashing LED was positioned at 3m from it and at 1 m high from the floor (Figure 2) [39]. While standing at 3m on the front of the flashing LED signal [21], participant had to stop the LEDs light as fast as possible for 100 repeated time by using the remote P-board.…”

“…As shown in Figure 4 the video clips were recorded at 240 fps and the flashing time interval period from a fame to the one just before was calculated as: FP2 -FP1 = (32341-32100) -1 = 240 fps. To get further accuracy, the video was deinterlaced using VirtualDub to 480 fps (Table 3), because the uncertainty [21] due to the video recording frame rate has a rectangular distribution [44,45] with semi-range of the time interval between two successive frames of the video recording (1/480 fps = 2.1ms) and it is calculated as:…”

“…Though, recently the Hong Kong Standards and Calibration Laboratory (SCL) has developed a new totalize method for the calibration of stopwatches [19] by using a high-speed video camera to record short videos clips with 240 or 480 frames per second (fps). In the present article we aim to detail the calibration of a new timing device that we have developed using the highspeed video recording method [19][20][21]. Than, we study its reliability and reproducibility for measuring visual simple reaction time.…”