以下是我修正后的代碼

#include <DFRobot_DHT11.h>

DFRobot_DHT11 DHT; //DHT－11 庫(kù)文件

#define Trig 11

#define Echo 12

#define Buzzer 2

#define DHTPIN 4

#define DHTTYPE DHT11

float sound_spd = 343; //聲速初始值

float distance, humid, temp; //距離，濕度，溫度

int LEDs; //LED點(diǎn)亮個(gè)數(shù)

void setup() {

Serial.begin(115200);

pinMode(Trig, OUTPUT);

pinMode(Echo, INPUT);

pinMode(Buzzer, OUTPUT);

}

void loop() {

//**************************************************************************************************測(cè)距

// Write a pulse to the HC-SR04 Trigger Pin//做一個(gè)10uS的TTL，激發(fā)測(cè)距模塊。

digitalWrite(Trig, LOW);

delayMicroseconds(2);

digitalWrite(Trig, HIGH);

delayMicroseconds(10);

digitalWrite(Trig, LOW);

distance = (pulseIn(Echo, HIGH) / 2) * sound_spd / 10000; //測(cè)距公式

// Send results to Serial Monitor//在串口監(jiān)視器顯示距離

Serial.print("Distance = ");

if (distance >= 400 || distance <= 2) {

Serial.println("Out of Range");

} else {

Serial.print(distance);

Serial.println(" cm");

}

//***********************************************************************************************報(bào)警模式

if (distance <= 20) {

tone(Buzzer, 1000);

LEDs = round(distance / 2);

for (int D = 10; D >= 10 - LEDs; D--) {

digitalWrite(D, HIGH);

}

delay(distance * 30);

noTone(Buzzer);

for (int i = 10; i >= 6; i--) {

digitalWrite(i, LOW);

}

}

//***********************************************************************************************修正模式

else {

noTone(Buzzer);

for (int i = 10; i >= 6; i--) {

digitalWrite(i, HIGH);

}

DHT.read(DHTPIN);

humid = DHT.humidity;

temp = DHT.temperature;

sound_spd = 331.4 + (0.606 * temp) + (0.0124 * humid); //聲速修正公式

// Send results to Serial Monitor//在串口監(jiān)視器顯示溫度，濕度，以及修正以后的聲速

Serial.print(" Correction: ");

Serial.print("\t");

Serial.print(" Temperature = ");

Serial.print(DHT.temperature);

Serial.print("C");

Serial.print("\t");

Serial.print(" Humidity = ");

Serial.println(DHT.humidity);

Serial.print("%");

Serial.print("\t");

Serial.print(" Sound Speed = ");

Serial.print(sound_spd);

Serial.println("m/s");

Serial.println(" ");

delay(1000);

}

delay(50);

}