Moisff

Hey guys, i'm currently in the process of building a flame detection circuit for a fire fighting robot. I thought i could use a Sharp GP2D120 to sense the IR source coming from a group of Candles situated in a maze. Unfortunately i'm running into trouble configuring this component to pick up the flame. Does anyone have any idea's as to how to do this? I know it's a distance sensor but i was pretty sure with some jiggery pokery i could make it work. HELP PLEASE!!

crutschow

I don't think jiggery pokery will help. The Sharp GP2D120 is an active IR distance sensor, i.e. it transmits an IR signal and detects the reflection. It's not designed for detection of external IR sources (and probably actively rejects them). Suggest you Goggle "flame detection" to find such detectors.

Norlin

yes, I believe the gp2d120 looks for Ir pulsed at a specific frequency, so wouldn't trigger a detection from a flame. You'd want to look for a photodiode that detects in the Ir wavelength and somehow shield it to make it highly directional.

Moisff

Thanks, that's kinda what i was expecting. Looks like i'm going to have some extra work to do over the next few weeks

dknguyen

What's wrong with a pyroelectric sensor? For the cost of a GPD120 you can also get some I2C-output thermopiles from Melexis.

ericgibbs

hi,
Look at this link.

UV is a good option for 'flame' detection.

http://www.iceweb.com.au/Technical/flame_and_gas.htm

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

Moisff

Thanks guys, that link is great by the way. Wish i found that sooner. I've opted to go for a phototransistor connected to a comparator LM339 (have four for each corner of the robot) Hopefully that should work. Goin to use the sharp components for their original purpose now!