//www.elegoo.com //2016.12.08 #include "SR04.h" #define TRIG_PIN 12 #define ECHO_PIN 11 SR04 sr04 = SR04(ECHO_PIN,TRIG_PIN); long a; void setup() { Serial.begin(9600); delay(1000); } void loop() { a=sr04.Distance(); Serial.print(a); Serial.println("cm"); delay(1000); }