【Arduino】超声波模块(HC-SR04)

还好，这个模块有现成的库可以用：

https://github.com/bosgood/arduino-playground/tree/master/lib/HCSR04Ultrasonic

以下只给出测试代码：

当距离小于20CM时蜂鸣器发出警报

#include "Ultrasonic.h"#define TRIGGER_PIN  12#define ECHO_PIN     13#define BUF_PIN      7Ultrasonic ultrasonic(TRIGGER_PIN, ECHO_PIN);void setup(){Serial.begin(9600);pinMode(BUF_PIN, OUTPUT);}void loop(){float cmMsec, inMsec;long microsec = ultrasonic.timing();cmMsec = ultrasonic.convert(microsec, Ultrasonic::CM);inMsec = ultrasonic.convert(microsec, Ultrasonic::IN);if(cmMsec < 20) {for(int i = 0; i < 80; i++) {digitalWrite(BUF_PIN, HIGH);delay(1);digitalWrite(BUF_PIN, LOW);delay(1);}}  Serial.print("MS: ");Serial.print(microsec);Serial.print(", CM: ");Serial.print(cmMsec);Serial.print(", IN: ");Serial.println(inMsec);delay(1000);}