超声波测距实现测距预警

#define Echo D2 #define Trig D8 #define BEEP D5 long getTime() { digitalWrite(Trig,HIGH);//******************* delayMicroseconds(10); //发送一个10微秒的脉冲 digitalWrite(Trig,LOW);//************ return pulseIn(Echo,HIGH); //波传输过程echo高电平，计算高电平时间就获取波传输的时间，单位是微秒 } void initChaoShengBo() { pinMode(Echo, INPUT); pinMode(Trig, OUTPUT); } void setup() { // put your setup code here, to run once: initChaoShengBo(); pinMode(BEEP, OUTPUT); digitalWrite(BEEP,HIGH); Serial.begin(115200); } void loop() { // put your main code here, to run repeatedly: //获取距离 long dis; dis = getTime()/58; Serial.print(dis); Serial.println("cm"); if(dis < 10){ digitalWrite(BEEP,LOW); }else{ digitalWrite(BEEP,HIGH); } delay(500); }