Keyestudio KS0436 Kit Manual page 288

}
void ask_pin_F()
{
digitalWrite(pinTrip, LOW);
voltage 2μs
delayMicroseconds(2);
digitalWrite(pinTrip, HIGH);
voltage 10μs，here at least 10μs
delayMicroseconds(10);
digitalWrite(pinTrip, LOW);
voltage
float Fdistance = pulseIn(pinEcho, HIGH);
difference
Fdistance= Fdistance/5.8/10;
Fspeed = Fdistance;
（unit：cm）
Fspeedd(front speed)
Serial.print("Fspeed = ");
Serial.print(Fspeed );
Serial.println(" cm");
}
// measure the front distance
// make ultrasonic emit LOW
// make ultrasonic emit HIGH
// make ultrasonic emit LOW
// turn time into distance
// read distance into
// read the time
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