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Topic: Using a capacitive soil moisture sensor to detect rain (Read 148 times) previous topic - next topic

Watcher

Hi!

I ve been using a the usual restive rain sensor  for a few months to detect rain but it soon failed due to corrosion of its exposed copper traces.

I then bought a capacitive soil moisture sensor from ebay like this one.
Its very easy to interface to arduino and modify the code to detect rain however the problem is that it has some exposed electronics on the sensor itself which is a problem if they are exposed to rain and the elements of nature.

Can anyone suggest  some method to insulate and protect the electronics of the board from rain but also leaving the rest of the sensor exposed ?

Possible approcahes :

(a) Heat shrinkable over the electronics. Unlikely to survive UV radiation from the sun however
(b) Hot glue over the electronics to provide water insulation. Comments?
(c) Silicon based fixing adhesive

Any input would be appreciated.




Rob_Muller

#1
Jul 20, 2019, 02:42 pm Last Edit: Jul 20, 2019, 02:47 pm by Rob_Muller
Put the electronics in an IP44 box (like this https://www.aliexpress.com/item/32840552018.html?), making a slit to expose the sensor. then waterproof that slit using hotglue, silicon paste or something like it.
Regards,

Rob

wvmarle

Fully enclosed casings will always get moisture in (especially if you try to mess around with hot glue), and that moisture has no way out. That's a common problem.

For permanently powered projects the inverted bucket design (waterproof container with some big openings in the bottom) works wonders. You may need some mesh to close off the openings to keep insects out.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

Watcher

Put the electronics in an IP44 box (like this https://www.aliexpress.com/item/32840552018.html?), making a slit to expose the sensor. then waterproof that slit using hotglue, silicon paste or something like it.
Yes I also thought of that as well...I might try it !

Watcher

Fully enclosed casings will always get moisture in (especially if you try to mess around with hot glue), and that moisture has no way out. That's a common problem.

For permanently powered projects the inverted bucket design (waterproof container with some big openings in the bottom) works wonders. You may need some mesh to close off the openings to keep insects out.
I agree with the trapped moisture issue.
However the problem here is slightly different as part of the PCB consists of the sensor itself that needs to be left exposed in rain and the rest needs to be protected:




wvmarle

So how does that preclude an inverted bucket container? Just let it stick out.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

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