需求
“An Arduino Uno wired to an HC-SR04 distance sensor: connect 5 V and ground, TRIG to D9, and ECHO to D10.”
接著試試Move TRIG to D7Add an LED that lights when the distance is short
Four-wire ultrasonic distance sensor wiring — VCC / GND / TRIG / ECHO. The textbook Adafruit / SparkFun tutorial layout used in robotics intro classes.
“An Arduino Uno wired to an HC-SR04 distance sensor: connect 5 V and ground, TRIG to D9, and ECHO to D10.”