How to Use the FC-37 Rain Sensor With an Arduino





Introduction: How to Use the FC-37 Rain Sensor With an Arduino

Hi! In my first instructable I will show you how to use the FC-37 rain sensor with an arduino. I am using an arduino nano but other versions will work just fine!

Step 1: Things You Need:

1x -- FC-37 and its controller board.


1x -- Arduino


1x -- Green Led


1x -- Red Led


some jumper wires

Step 2: The Wiring

So to connect the FC-37 and the LEDS to the arduino follow these steps.

5v ------------ VCC (controller board)

GND ------------ GND (controller board)

A0 ------------ A0 (controller board)

You do not need to use D0 on the controller board.

Now on the other side of the controller board there are two pins. You have to connect them to the FC-37. You can connect them in any direction, It doesn't matter. There is also a potentiometer on the controller which adjust sensitivity although you don't have to mess with it to get it working.


and for the LEDS

D2 ------------------ positive of the RainLED (in my case a red one)

D3 ------------------ positive of the DryLED (in my case a green one)

GND ------------------ negative of both LEDS


Step 3: The Code

This is the .ino that you need to get it working.

Step 4: Preview

Alright if you did everything well it should work something like this! Just be careful not to fry the arduino if you replicate this!



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    6 Discussions


    6 months ago

    My comment was: "I think you dryLED is Green and your RainLED is Red!".

    1 reply

    Yes! Thanks for pointing it out to me. Turns out I have a typo in the instructable!

    It should be fixed now! Thanks again!


    6 months ago

    What's going on here? I posted a comment a few minutes ago and now it has disappeared.


    6 months ago

    I think your dryLED is Green and your RainLED is Red.

    That's a neat sensor :) Thanks for sharing!

    1 reply