Arduino 超音波之控制

請依下圖接線

請鍵入下列程式：(以 com 串列訊息室窗觀察)
#define trigP 6
#define echoP 7
const int T25 = 29 , samplePeriod = 50;
int Distance, Duration;
unsigned long t0 = 0;
void setup() {
     Serial.begin(9600);
     pinMode(trigP,OUTPUT);
     pinMode(echoP,INPUT);
}

void loop() {
     if(millis()-t0>=samplePeriod){
          usonicRead();
          t0 = millis();
          Serial.print("距離: ");Serial.print(Distance);Serial.println(" 公分.");
     }
}

void usonicRead(){
     digitalWrite(trigP,HIGH);
     delayMicroseconds(10);
     digitalWrite(trigP,LOW);
     Duration = pulseIn(echoP,HIGH)/2;
     Distance = Duration/T25;
}