超声波传感器

Question

现在我正在使用两个超声波传感器，但我发现它们在室外变得不稳定，给出随机读数，.....although，它们在房间内正常工作，.....how，我能解决这个问题吗？这就是代码，似乎关闭传感器总是在读取，我检查了线路，它是好的，所以我不知道问题在哪里??

    #define trig 2
    #define echo 3
    #define led 7
    #define relay 4
    #define trig2 10
    #define echo2 9
    #define led2 8

  long duration,distance,OnSensor,OffSensor;
void setup() {
  // put your setup code here, to run once:
  pinMode(echo,INPUT);
  pinMode(echo2,INPUT);
  Serial.begin(9600);
  pinMode(led,OUTPUT);
  pinMode(led2,OUTPUT);
  pinMode(relay,OUTPUT);
  pinMode(trig,OUTPUT);
  pinMode(trig2,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(led,LOW);
  digitalWrite(led2,LOW);
  digitalWrite(relay,LOW);
  SonarSensor(trig2, echo2);
  OffSensor = distance;
  delay(50);
  SonarSensor(trig, echo);
  OnSensor=distance;

  if(OnSensor<80&&OffSensor>=80){//sensor 1 activated
    digitalWrite(led,HIGH);
    digitalWrite(relay,HIGH);
    delay(150);
    digitalWrite(led,LOW);
    digitalWrite(relay,LOW);
    delay(1000);
    digitalWrite(led,HIGH);
    digitalWrite(relay,HIGH);
    delay(150);
    digitalWrite(led,LOW);
    digitalWrite(relay,LOW);

  }
  else if(OnSensor>80&&OffSensor>80){//No sensor activated
    digitalWrite(led,LOW);
    digitalWrite(relay,LOW);
  }
  else if(OnSensor>80&&OffSensor<80){//sensor2 activated
        digitalWrite(led2,HIGH);
        digitalWrite(relay,LOW);
        delay(5000);
  }
  else if(OnSensor<80&&OffSensor<80){//Both sensors activated
       digitalWrite(led2,HIGH);
       digitalWrite(led,HIGH);
       digitalWrite(relay,LOW);
       delay(3000);
  }
}
void SonarSensor(int trigPin,int echoPin)
{
digitalWrite(trigPin, LOW);
delayMicroseconds(2);
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
duration = pulseIn(echoPin, HIGH);
distance = duration*0.034/2;
}

Answer 1

我认为这里有两个问题

1. 您使用2传感器
2. 列表项

在户外使用

根据我的经验，超音波可以在物体周围弹跳很多次。根据您的设置，第二个传感器可能会读取回波表单第一个传感器。按照以下步骤1。尝试每次使用1个传感器来查看它是否有错误2。如果单个传感器工作正常，则应在传感器读取3之后添加更多延迟。绘制数据以查看是否需要数字滤波器来改进第3步的读取，如果您按阈值关闭传感器，您可以看到我的示例代码。此代码的工作方式与按钮脱弹相同，因此需要连续触发10次，以防止虚警(此代码用于单个传感器)。

#define  ULTRASONIC_TRIG_PIN  8
#define  ULTRASONIC_ECHO_PIN 7

#define RELAY_PIN 4
/**/
#define ULTRASONIC_INTERVAL_MS 100//50
#define ULTRASONIC_TRIG_COUNT_THRESH 10
#define ULTRASONIC_DISTACE_THRESH_CM 50
/**/
#define RELAY_TRIG__INTERVAL_MS 5000
#define RELAY_TRIG_LOGIC HIGH



void setup()


{

  pinMode (RELAY_PIN, OUTPUT);
  pinMode (ULTRASONIC_TRIG_PIN, OUTPUT);
  pinMode (ULTRASONIC_ECHO_PIN, INPUT);
  Serial.begin(115200);
}
void loop()
{
  static unsigned long ultrasonic_timer = millis();
  static unsigned long relay_trig_timer = millis();
  static float us_distance_cm = 0;
  static int us_trig_count = 0;
  static byte relay_state = !RELAY_TRIG_LOGIC; // initial value as off;
  if (millis() - ultrasonic_timer >= ULTRASONIC_INTERVAL_MS) {
    ultrasonic_timer += ULTRASONIC_INTERVAL_MS;
    us_distance_cm = getDistanceCM();

    if (us_distance_cm <= ULTRASONIC_DISTACE_THRESH_CM) {
      if (us_trig_count >= ULTRASONIC_TRIG_COUNT_THRESH) {
        digitalWrite(RELAY_PIN, RELAY_TRIG_LOGIC);
        relay_state = RELAY_TRIG_LOGIC;
        relay_trig_timer = millis();
      }
      else {
        us_trig_count++;
      }

    }
    else {
      us_trig_count = 0;

    }
    Serial.print("distance = ");
    Serial.print(us_distance_cm);
    Serial.print("cm, relay = ");
    Serial.print(relay_state);
    Serial.print(", count = ");
    Serial.println(us_trig_count);
  }
  if (relay_state == RELAY_TRIG_LOGIC) {
    if (millis() - relay_trig_timer > RELAY_TRIG__INTERVAL_MS) {
      relay_state = !RELAY_TRIG_LOGIC;
      digitalWrite(RELAY_PIN, !RELAY_TRIG_LOGIC);
    }
  }


}

float getDistanceCM() {
  digitalWrite(ULTRASONIC_TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(ULTRASONIC_TRIG_PIN, LOW);
  unsigned long duration = pulseIn(ULTRASONIC_ECHO_PIN, HIGH, 50000);
  float distance = float(duration * 343) / 20000.0;
  delay(5);
  return distance;
}