Getting started with the Maxbotix sonar sensor - quick start guide

Step 5 Run some code..

Run some code!
The MaxSonar EZ1 outputs analog voltage with a scaling factor of (Vcc/512) per inch. A supply of 5V yields ~9.8mV per inch. On the other hand, the Arduino’s analog-to-digital converter (ADC) has a range of 1024, which means each bit is ~4. 9mV. For that reason, to convert the number returned by the ADC to inches, we have to divide by 2.

// using the maxsonar quick start http://www.adafruit.com
// http://www.adafruit.com/index.php?main_page=product_info&cPath=35&products_id=172

int sonarPin = 0; //pin connected to analog out on maxsonar sensor
int piezoPin = 9; // specifies the pin connected to piezo from Arduino
int inchesAway; // inches away from the maxsonar sensor

void setup() {
pinMode(piezoPin, OUTPUT);
//Serial.begin(9600); // starts serial communication, used for debugging or seeing the values
}

void loop() {
inchesAway = analogRead(sonarPin) /2; // reads the maxsonar sensor and divides the value by 2
// approximate distance in inches
//Serial.print(inchesAway); // prints the sensor information from the maxsonar to the serial monitor
//Serial.println(" inches from sensor");

if (inchesAway < 24) { // if something is 24 inches away then make a 1khz sound
digitalWrite(piezoPin, HIGH);
delayMicroseconds(500);
digitalWrite(piezoPin, LOW);
delayMicroseconds(500);
}
}