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Frustration over IR transmitter and receiver how do I..?

Discussion in 'Radio and Wireless' started by CABBAGE, Jan 24, 2019.



    Nov 17, 2018
    I have been trying in vein to assemble a simple breadboard example of an IR transmitter and a receiver (no arduino) just to see it work. First question: can anyone provide a link to a circuit diagram that works? Second question: what state does the transmitter (with 555) need to be in? Astable or monostable and does it produce 38Khz to be received by a tsXX38 reciever? I very new to this and I'm trying to make one work just for proof of concept, then I can adapt from there. Just getting the two to work together has proved to be elusive. All I'm looking for is a transmitter to be received by a receiver and light up an LED (or perhaps output 5V power) if someone can provide some clues or a diagram it would be greatly appeciated, Thanks in advance C
  2. Harald Kapp

    Harald Kapp Moderator Moderator

    Nov 17, 2011
    I don't have one, but there should be plenty to be found by a search engine
    It depends on what you want to achieve. If you want to transmit a signal that can be distinguished from ambient light you'd use an AC waveform, therefore the astable mode is in order.
    It can, provided you supply the right component values. There are plenty of 555 calculators online.
    Type? I can't find a tsXX38 receiver. A basic receiver should receive IR light of any modulation frequency. The limits are stated in the datasheet. Should this be a module, other limits may apply as per datsheet of the module. Do you have a datasheet or a link to one?

    You can use a red LED instead of the IR LED to check whether the transmitter operates at all. Or use the camera of your smartphone. Most will show an active IR source as a bright dot.
  3. BobK


    Jan 5, 2010
    TSOP receivers are very finicky about the signal they receive. It must be at the specified frequency ± a few percent. It must also be modulated. If you produce a steady 38KHz, it will initially recognize it, then ignore it. You must produce bursts of a specific range of length followed by gaps of a specific range of lengths. The datasheet will give these figures.

    So you cannot just use the raw output of the TSOP as an on off signal. The simplest way to accomplish that is to send repeating bursts with the specified gap. The receiver then sees a signal that is a square wave with a specific duty cycle (ration of on time to period). So the simplest way to implement the receiver would be to trigger a monostable that is slightly longer than the period of the signal (not the carrier). So if you put out a 100uS pulse followed by a 100uS gap, you would set the monostable at say 300uS. Then it would turn on when the first pulse was detected and off 200uS after the last pulse is detected.

    Exactly what receiver are you using? Can you link to a datasheet?

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