IRED Distance Meter
IRED Distance Meter
(OP)
I made an IRED distance detector circuit based on MX-171 AF IC from Macronix. I have covered the Photodiode and the IRED LED with a filter. The filter is a focusing lens with IRED-pass-filter material. It works perfectly in indoor. But it really unstable when I tried to use it outdoor. I live in Indonesia, country with very bright sunlight.
Any comments or suggestion ? Thank you.
Any comments or suggestion ? Thank you.





RE: IRED Distance Meter
narrow band amplifier at the receiver side.
<nbucska@pcperipherals.com>
RE: IRED Distance Meter
> Bear in mind that daylight ranging is extremely limited, given the available power that you probably have to play with.
> Use a retroreflector material such as bicycle tail reflector or Scotchlite. Most laser rangefinders use similar reflectors to get adequate performance for longer ranges and daytime.
> If you are trying something that's significantly difficult, you may need an APD or photomultiplier as a detector.
TTFN
RE: IRED Distance Meter
You did not decribe your receiver circuit, but AC coupling is good, but also including a bias loop (a slow loopo, something like an AGC) to make sure there is always enough voltage across your diode may help as well.
Two other solutions: Come on up to Thailand where its cloudy all day, or use it at night
Good luck.
RE: IRED Distance Meter
Also modulating the transmitter beam and using a receiver tuned to the modulation frequency really made a difference.
RE: IRED Distance Meter
Also, pulsing the signal must be coupled with a matched filter input with no more bandwidth than absolutely necessary to minimize the noise bandwidth.
TTFN
RE: IRED Distance Meter