Ultrasonic Rangefindercalibration | smoothing

About Ultrasonic Sensors

- Works like radar or sonar, but with ultrasound waves

- Evaluates the distance of an object/target by generating ultrasound waves and interpreting the echoes

QuickTime™ and a decompressor

are needed to see this picture.

Ultrasound is sound pressure with a greater

frequency (greather than ~20kHz) than the threshold

of human hearing

Ultrasound is sound pressure with a greater

frequency (greather than ~20kHz) than the threshold

of human hearing

Applications

• Monitoring fetuses

• Burglar alarmsQuickTime™ and a

decompressorare needed to see this picture.

QuickTime™ and a decompressor

are needed to see this picture.

MaxBotix LV-MaxSonar® - EZ1

GND+5

ANALOG SIGNAL

Specs:• 2.5-5.5V

power supply

• Reads up to every 50ms

Specs:• 2.5-5.5V

power supply

• Reads up to every 50ms

Detection Patterns

Beam Characteristics:

(A) 0.25-inch diameter dowel

(B) 1-inch diameter dowel

(C) 3.25-inch diameter rod

(D) 11-inch wide board moved left to right

Beam Characteristics:

(A) 0.25-inch diameter dowel

(B) 1-inch diameter dowel

(C) 3.25-inch diameter rod

(D) 11-inch wide board moved left to right

Distance from the Sensor

// This program prints the distance of a target object// from an ultrasonic sensor

int ultra = 0; // select the input pin for the sensorint val = 0; // variable to store the value coming from the sensor

void setup() { Serial.begin(9600);}

void loop() { val = analogRead(ultra); // read the value from the sensor long inch;

inch = val/2; // converts value to inches

Serial.print(inch); Serial.print("inch"); Serial.println();}

Smoothing/Calibration

Smoothing is a process by which an analog input is read repeatedly, dumped into an array, and a running average is calculated and printed to the computer

http://a.parsons.edu/~leek603/UltrarangeCalibration.pde

Sensor Read Playing Noise

http://a.parsons.edu/~leek603/UltraSpeaker.pde

Where to buy

• Sparkfun (expensive: $24.95-$29.95)

• Digikey (annoying but cheap: $8.95-$16.32)