The HC-SR04 measures distances using ultrasound and outputs them in centimeters (cm).

Technical Information

• Dimensions: 45mm x 20mm x 17mm
• Supply voltage of 5V with a current consumption of less than 2mA
• up to 50 measurements per second possible

Programming (Arduino)

int trig = 1;  // Trig-Pin des Sensors ist an Pin 1 angeschlossen.
int echo = 2;  // Echo-Pin des Sensors ist an Pin 2 angeschlossen.

// Definieren der Variablen
unsigned int time = 0;
unsigned int distance = 0;

void setup() {
Serial.begin(9600); // Startet den Seriellen Monitor
pinMode(trig, OUTPUT);  
pinMode(echo, INPUT);
}

void loop() {
digitalWrite(trig, HIGH);
delayMicroseconds(10);
digitalWrite(trig, LOW);
distance = time / 58;
Serial.println(distance);
}

Programming (Blockly)

In Blockly the sensor can be read out via the following block:

Select the port where you have connected the sensor from the drop-down menu. Trigger and echo pin will be adjusted automatically.