## Measure the analog levels and digital signals in an input device # Author : Sunghyun-An  The GND, echo, and trigger parts of the sonar sensor were temporarily soldered to allow measurement.  The basic state of the oscilloscope.  The blue line is connected to GND and the other two lines are connected to echo and trigger.  In the case of sonar sensor, signal is sent when it is low - high, and it is receiving signal when it is high - low. The time zone between the low - high and high - low oscilloscopes is in •Ïs. When programming, you should have a formula to calculate the distance and the speed of the time and sound.  The graph is enlarged, but it is not visible in the photograph, but there is a graph with thin points. As a result of rough estimation, the time of the value between Low - High and High - Low is 640•Ïs.