I am working on a project which requires the use of sensors and i don't know which one to use so i would like to know the difference between the two.

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  • 1
    They seem pretty similar. One uses surface-mount components and the other through-hole components. But my guess would be that they do pretty much the same thing. I'd prefer the first one, as it have some bypass capacitors on it, which could make it's signal a bit more stable.
    – Gerben
    Apr 8 '19 at 18:43
  • 2
    It would be helpful if you would provide spec sheets or at least part numbers and sources for the 2 boards. Otherwise we have to do some guesswork from the images provided.
    – Duncan C
    Apr 8 '19 at 21:55

Apart from the obvious construction and component differences the two sensors seem totally equivalent from their look. They seems to both be FC-51 modules: those are “line followers” meaning one diode (the clear one) emits infrared light and the other (the dark one) measure the amount of IR light reflected by the surface in front of them. The potentiometer is there to determine the triggering level so that when powered you can have a LOW signal on the OUT pin when the threshold is reached.

  • How do you know, that the output signal is digital? Wouldn't it be also possible, that the output voltage may be analog and the potentiometer controls the gain? I don't know, how I should be able to tell from the pictures.
    – chrisl
    Apr 9 '19 at 20:21
  • Because those sensors are quite common and called FC-51 codetipste.blogspot.com/2017/04/ir-sensor-arduino.html?m=1. Apr 9 '19 at 22:36
  • Not to mention I stated "they seem totally equivalent by their look": without further information that is my best guess... Apr 9 '19 at 22:38
  • Ah, ok. Good, that you included the part number (FC-51), so that we have a reference. +1
    – chrisl
    Apr 10 '19 at 6:48
  • How can i find the positive and negative terminal of transmitter and receiver of sensor in first pic?@RobertoLoGiacco Apr 12 '19 at 7:05

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