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Chapter 7: Navigating with Infrared HeadlightsChapter 7: Navigating with Infrared Headlights

Presentation based on:

"Robotics with the Boe-Bot"By Andy LindsayParallax, Inc

Presentation developed by:Presentation developed by:

Martin A. HebelMartin A. HebelSouthern Illinois University CarbondaleSouthern Illinois University CarbondaleCollege of Applied Sciences and ArtsCollege of Applied Sciences and ArtsElectronic Systems TechnologiesElectronic Systems Technologies7/6/04

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InfraredInfrared

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Infrared HeadlightsInfrared Headlights

Close object will reflect the light back to the sensor.

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Parts and AssemblyParts and Assembly

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CircuitCircuit

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To use the sensor:• FREQOUT to the LED at 38,500KHz• Record the detector's output.

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Why 38,500?Why 38,500?

Infrared is abundant around us (emitted as part of heat from many objects – including us).

But, objects do not emit it on and off at 38,500Hz.

The detector will ignore any source of IR except at that frequency.

RF systems and FM and AM radio work the same way – ignoring source and frequencies they don't care about.

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Object Detection and AvoidanceObject Detection and Avoidance

"RoamingWithIR.bs2"

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To change the sensitivity, change the size of the LED resistor.