Conectar el ultrasonic range sensor HC-SR04 a arduino

Conexión:

GND - tierra
ECHO - digital pin 2 de arduino
TRIG - digital pin 3 de arduino
Vcc   -  5v de arduino

Código:


/*
 * Define the pins you want to use as trigger and echo.
 */

#define ECHOPIN 2        // Pin to receive echo pulse
#define TRIGPIN 3        // Pin to send trigger pulse

/*
 * setup function
 * Initialize the serial line (D0 & D1) at 115200.
 * Then set the pin defined to receive echo in INPUT
 * and the pin to trigger to OUTPUT.
 */

void setup()
{
//  Serial.begin(115200);
  Serial.begin(9600);
  pinMode(ECHOPIN, INPUT);
  pinMode(TRIGPIN, OUTPUT);
}

/*
 * loop function.
 *
 */
void loop()
{
  // Start Ranging
  digitalWrite(TRIGPIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIGPIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIGPIN, LOW);
  // Compute distance
  float distance = pulseIn(ECHOPIN, HIGH);
  distance= distance/58;
  Serial.println(distance);
  delay(200);
}

fuente: http://www.xappsoftware.com/wordpress/2012/03/15/how-to-interface-the-hc-sr04-ultrasonic-ranging-module-to-arduino/



Ejemplo de Paking assistant:
http://electronicavm.wordpress.com/2011/07/07/sensor-de-aparcamiento-con-arduino/