c++ - Arduino HC-SR04 传感器，平均数据

Question

我正在尝试使用根据与超声波传感器的距离计算出的平均值来控制 LED。我有数据被平均，但它从加电开始是连续的。我想在每十次读数后重新计算平均值。谁能告诉我需要更改哪些内容才能重新计算每 10 个值的平均值而不是计算运行平均值？

const int TrigPin = 8;
const int EchoPin = 9;
const int LedPin = 13;
const int numReadings = 5;
long Duration = 0;

int readings[numReadings];
int index = 0;
int total = 0;
int average = 0;

void setup() {
  Serial.begin(9600);  
  pinMode(LedPin, OUTPUT);
  pinMode(TrigPin, OUTPUT);
  pinMode(EchoPin, INPUT);
  for (int thisReading = 0; thisReading < numReadings; thisReading++)
    readings[thisReading] = 0;  
}

void loop() {
  digitalWrite(TrigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(TrigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(TrigPin, LOW);

  Duration = pulseIn(EchoPin, HIGH);
  long Distance_mm = Distance(Duration);

  //Serial.print("Distance = ");
  //Serial.print(Distance_mm);
  //Serial.println(" mm");

  total= total - readings[index];
  readings[index] = analogRead(EchoPin);
  total = total + readings[index];
  index = index + 1;

  if (index >= numReadings)
    index = 0;

  average = total / numReadings;
  Serial.print("Dist_avg = ");
  Serial.print(average);
  Serial.println("mm");
  delay(100);

  if (average > 400)
  {
    digitalWrite(LedPin, HIGH);   // turn the LED on (HIGH is the voltage level)
  }
  else
  {
    digitalWrite(LedPin, LOW);    // turn the LED off by making the voltage LOW
  }

}

long Distance(long time)
{
  long DistanceCalc;
  DistanceCalc = ((time /2.9) / 2);
  return DistanceCalc;
}

Answer 1

您只需要更改您的代码，以便它在 index == 10 时计算平均值。如果您将 numReadings 更改为 10，您可以尝试这样的代码:

void loop(){
  ...

 //total= total - readings[index];
 //you don't need the array here anymore
 //readings[index] = analogRead(EchoPin);
 //total = total + readings[index];
 total = total + analogRead(EchoPin);
 index = index + 1;

 if (index >= numReadings)
 {
   index = 0;

   average = total / numReadings;

   Serial.print("Dist_avg = ");
   Serial.print(average);
   Serial.println("mm");
   delay(100);

   if (average > 400)
     digitalWrite(LedPin, HIGH);   // turn the LED on (HIGH is the voltage level)
   else
     digitalWrite(LedPin, LOW);    // turn the LED off by making the voltage LOW

   total = 0;
 }