Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: JDeschambault on March 14, 2007, 07:32:30 PM

Title: Fixing my IR
Post by: JDeschambault on March 14, 2007, 07:32:30 PM
Here it goes... I am on my 2nd robot. and on this one i want to use IR. I have reseached it with this web site and several others. I bought the parts build it and plugged it in to test my ciruits and see what kind of readings i would be getting. the thing is i am only getting readings 2 inches in front of it. Further I am not sure the program i wrote is giving me the readings it should or if i need to write a different program. (the Program i wrote is set up to read a photoresister.) i used the IR sensor SCHEMATICS - INFRARED EMITTER DETECTOR. and in place of the 120 ohms, used 150 and in place of the 11k used 10k. (closest i could find at the time) any help to solve this would be great...  :o
Title: Re: Fixing my IR
Post by: Kohanbash on March 14, 2007, 07:50:08 PM
Is the your IR sensor analog or digital. Is the photoresistor program designed to act on a value or is it thresholded to either be on or off? If you have a meter test the output of the IR sensor without being attached to the micro.
Title: Re: Fixing my IR
Post by: JDeschambault on March 14, 2007, 08:05:53 PM
the Program is a 5DEC value, the IR i am not sure but if i was guessing Ang. cause it is not simply on or off. (See http://www.societyofrobots.com/schematics_infraredemitdet.shtml to see the ciruit i built)   :-\

i have a Meter but not sure How to test it, and if it should have power running through it...? ???
Title: Re: Fixing my IR
Post by: Kohanbash on March 14, 2007, 08:20:36 PM
What type of IR sensor is it?
To test have the circuit powered and measure the voltage between Vout and GND
Title: Re: Fixing my IR
Post by: JDeschambault on March 14, 2007, 08:42:05 PM
obstacle detection, and i will test it once i get home tonight.
Title: Re: Fixing my IR
Post by: Admin on March 16, 2007, 05:43:08 PM
actually, for that sensor two inches sounds about right.

you have a few options . . . one would be to use more emitter LEDs, and/or brighter emitter LEDs. another other option would be to do signal modulation to remove background noise. and lastely, you could use op-amps to boost your signal.

if you want really good range, the best method is to use Sharp IR rangefinders (http://www.societyofrobots.com/sensors_sharpirrange.shtml)