1. How an Ultrasonic Range Finder works
4.1 Ultrasonic Sensor
How an Ultrasonic Range Finder works

2. 4.1 Ultrasonic Sensor Ultrasonic Range Finder NewPing Library
DC Motor Application

3. 4.1 Ultrasonic Sensor
The sensor releases out an ultrasonic frequency every few milliseconds
The sensor then waits to hear for the reflected frequency
The time it takes for the sensor to send the pulse and receive it back again is how the distance is calculated
Infrared Sensors also work in the same principle of “Time of Flight”

4. 4.1 Ultrasonic Sensor
Wall

5. 4.1 Ultrasonic Sensor
An ultrasonic sensor measures the range from the sensor that are facing perpendicular to it.
Distance = Velocity x Time
Distance
Velocity
Time

6. 4.1 HC-SRF04
Echo Output
Trigger Input

7. 4.1 HC-SRF04 The sensor sets an 8 cycle burst of 40KHz of Ultrasound
Waits for an Echo to be sent back from a distant object
Range is calculated through the time interval between sending trigger signal and receiving echo signal.
Infrasound
- 20Hz
Acoustic
20Hz - 20kHz
Ultrasound
20kHz - 2MHz +

8. 4.1 Breadboard Diagram – US Sensor
Hardware: Ultrasonic Sensor A Flat Object

9. 4.1 Ultrasonic Sensor Testing
After you wired up the schematic properly you should be getting values returned in Centimeters.

10. Adding Haptic Feedback with Motors
4.1 Ultrasonic Sensor
Adding Haptic Feedback with Motors

11. 4.1 Ultrasonic Sensor Testing
We will now add motors to give a vibrational feedback that will represent the given range from the ultrasonic sensor.

12. 4.1 Breadboard Diagram - Haptic Feedback
Hardware: DC Motor Diode Transistor Resistor