Connect with us

Best Infrared beam emitter and sensor?

Discussion in 'Datasheets, Manuals and Component Identification' started by Liamlambchop, Sep 25, 2011.

Scroll to continue with content
  1. Liamlambchop


    Sep 19, 2011
    Hey guys,

    I am looking to buy a IR beam emitter (is this known as an IR LED?) and a photodiode sensor to go with it.
    I am going to be using them outside and they will be used for a people counting device. The setup will be thus:
    When people walk through the beam, IR radiation to the photodiode is momentarily stopped, and an arduino, which is connected to the photodiode, will recognise this as a count. The arduino will then output that data to a GSM modem, which will send the info to a webpage server.
    What IR beam emitter and photodiode do you recommend I buy? I've noticed that there are a whole lot of IR LEDs which emit IR at a whole lot of different wavelengths, and likewise for photodiodes and receiving the IR. How do I know what wavelength I should buy? I need something that'll be very durable, because it'll be used outside in rain, hail, and shine.

  2. duke37


    Jan 9, 2011
    I doubt if the wavelength is important, just get a matching pair.

    However, there will be a problem with ambient light. This can be alleviated by switching the led at high frequency and then filtering the received signal at that frequency (sychronous detection?).

  3. Liamlambchop


    Sep 19, 2011
    Thanks Duke.
    I am going to use an arduino to make the LED switch at 38KHz, and then use a 38KHz receiver to detect it.
    Should work just fine.
    Do you, or does anyone else, know where I could get some lens' for my transmitter and/or receiver, just in case I need the signal focused?
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day