Getting Started With the Maxbotix Sonar Sensor - Quick Start Guide

The MaxSonar EZ1 provides very short to long-range detection and ranging, in an incredibly small package. It can detect objects from 0-inches to 254-inches (6.45-meters) and provides sonar range information from 6-inches out to 254-inches with 1-inch resolution. (Objects from 0 inches to 6-inches range as 6-inches.) The interface output formats included are pulse width output (PWM), analog voltage output (Vcc/512 volts per inch), and serial digital output (9600 baud). A good sensor for when a Sharp IR distance sensor won't cut it.

If youre a pro cut straight to the data sheet- if not, here's a quick start guide on using the Maxbotix sonar sensor&

Things youll need:

An Arduino
A half size breadboard
A piezo buzzer
Wires
MaxSonar sensor

All of these are available in the Adafruit store.

Solder 3 wires to the Maxbotix sonar sensor. Ground, power and analog. Thats all well need for this simple test, and for the most part if youre just using this sensor with an Arduino its all youll likely use.

Using the diagram, wire it up!

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);
}
}