Proximity Sensors Tahani Almanie Physical Computing Presentation Outline

+ Proximity Sensors Tahani Almanie | Physical Computing

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

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

+ Types of proximity sensors n Infrared sensor It transmits IR light by an IR LED and measures the time it takes the light to return from the object n Ultrasonic sensor It generates high frequency sound waves and receives the echo reflected by an object. n Laser sensor (LIDAR) 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.

+ Evaluation of Infrared sensor Advantages : n It uses non-visible light for detection. n They are cheap sensors (between $10 -$20). Disadvantages : n n n Very sensitive to IR lights and sunlight. Short range detection (less than 1. 5 m) Weakness to darker colors such as black.

+ Evaluation of Ultrasonic sensor Advantages : n n 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 : n n n 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

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

+ How to measure distance with the Arduino Equipment required n n n An Arduino A breadboard An LCD screen Jump wires Max. Sonar sensor Max Sonar sensor v It detects objects from 0 -inches to 254 inches (6. 45 -meters) v Objects from 0 -inches to 6 -inches range as 6 - inches

+ How to measure distance with the Arduino Diagram:

+ How to measure distance with the Arduino Code:

+ References n http: //www. intorobotics. com/types-sensors-target-detectiontracking/ n http: //www. societyofrobots. com/member_tutorials/book/export/ html/71 n http: //www. dummies. com/how-to/content/how-to-measuredistance-with-the-arduino. html n http: //www. instructables. com/id/Max-Sonar-EZ 0/ n http: //www. instructables. com/id/Getting-started-with-the. Maxbotix-sonar-sensor-q/? ALLSTEPS n http: //oceanservice. noaa. gov/facts/lidar. html