1. + Proximity Sensors Tahani Almanie | Physical Computing

2. + Presentation Outline Criteria to choose the right sensor Types of proximity sensors Evaluation of three proximity sensor types How to measure distance with the Arduino

3. + Criteria to choose the right sensor Accuracy - the accuracy is very important in detecting and tracking objects. Environmental Condition – any sensor has its operational limits such as the temperature and humidity. Cost – depending on the budget allocated to a project, you can select the approprate sensor. Technology used – light, sound, laser

4. + Types of proximity sensors Infrared sensor Ultrasonic sensor Laser sensor (LIDAR) It transmits IR light by an IR LED and measures the time it takes the light to return from the object It generates high frequency sound waves and receives the echo reflected by an object. The distance is measured by calculating the speed of light (laser) and the time since light is emitted and until it is returned to the receiver.

5. + Evaluation of Infrared sensor Advantages : It uses non-visible light for detection. They are cheap sensors (between $10-$20). Disadvantages : Very sensitive to IR lights and sunlight. Short range detection (less than 1.5 m) Weakness to darker colors such as black.

6. + Evaluation of Ultrasonic sensor Advantages : Accurate detection even of small objects. Longer range detection than IR sensors (6- 8 meters) Works in critical conditions such as dirt and dust or under sunlight. Not dependent on the object colors. Disadvantages : Must view a high density surface for good results Could have false responds for some loud noises Can be affected by environment changes such as temperature and humidity

7. + Evaluation of Laser sensor Advantages : Long range detection. (up to 40 m) Very precise in measurement. Very Quick readings. High performance under direct sunlight. Disadvantages : Very expensive! (over $85)

8. + How to measure distance with the Arduino Equipment required An Arduino A breadboard An LCD screen Jump wires MaxSonar sensor  It detects objects from 0-inches to 254- inches (6.45-meters)  Objects from 0-inches to 6-inches range as 6- inches

9. + Diagram: How to measure distance with the Arduino

10. + Code:

11. + References http://www.intorobotics.com/types-sensors-target- detection-tracking/ http://www.intorobotics.com/types-sensors-target- detection-tracking/ http://www.societyofrobots.com/member_tutorials/book/ex port/html/71 http://www.societyofrobots.com/member_tutorials/book/ex port/html/71 http://www.dummies.com/how-to/content/how-to-measure- distance-with-the-arduino.html http://www.dummies.com/how-to/content/how-to-measure- distance-with-the-arduino.html http://www.instructables.com/id/Max-Sonar-EZ0/ http://www.instructables.com/id/Getting-started-with-the- Maxbotix-sonar-sensor-q/?ALLSTEPS http://www.instructables.com/id/Getting-started-with-the- Maxbotix-sonar-sensor-q/?ALLSTEPS http://oceanservice.noaa.gov/facts/lidar.html

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