Cheap(ish) rain sensor?

NJ Roadmap · Feb 21, 2007

I'm looking for one for a little garden project I'm doing but don't want to spend more than about £20 excl. postage. Has anyone used any of these?

NJ Roadmap · Feb 21, 2007

I am looking for an ready-made one rather than a home-made tipping bucket solution with a reed switch as has been discussed in the past.

Roff · Feb 21, 2007

Do you want to simply sense rain, or do you want to measure it?

NJ Roadmap · Feb 21, 2007

Just sense it.

Nigel Goodwin · Feb 21, 2007

The usual solution is just a PCB with interleaving 'fingers', the water makes a conductive path across them - veroboard can be used as well, just link alternate tracks.

NJ Roadmap · Feb 21, 2007

I had a look at the link about the PCB-based sensor posted during a previous discussion, it seems simple enough but I was wondering what kind of reliability issues would be associated with this due to water stagnation?

For reference, the link is: https://www.aaroncake.net/circuits/raindet.htm

Roff · Feb 21, 2007

NJ Roadmap said:
I had a look at the link about the PCB-based sensor posted during a previous discussion, it seems simple enough but I was wondering what kind of reliability issues would be associated with this due to water stagnation?

For reference, the link is: https://www.aaroncake.net/circuits/raindet.htm

Stagnation? Put it where the water will evaporate.

Nigel Goodwin · Feb 21, 2007

Ron H said:
Stagnation? Put it where the water will evaporate.

And gold plate the PCB, to avoid corrosion!.

Rolf · Feb 21, 2007

NJ Roadmap said:
I had a look at the link about the PCB-based sensor posted during a previous discussion, it seems simple enough but I was wondering what kind of reliability issues would be associated with this due to water stagnation?

For reference, the link is: https://www.aaroncake.net/circuits/raindet.htm

I think that if you tinned the PCB traces and tilted the board slightly so that the rain would drain off fairly rapidly, it would last for a long time. You might have to put some spikes on it to keep the birds off.

sriram karhik · Feb 22, 2007

hi friend

hi,
i am a new user to this .i am doing my engg. in india and i am in a situation to some project on electrical or electronics.if you have any ideas regarding these(headings,circuitsetc...,) please inform me as soon as possible

ThermalRunaway · Feb 22, 2007

I've often wondered how the rain sensors on cars work. Some models can sense if it's raining, and adjust the repetativeness of the windscreen wipers to suit. Some better models go even further and seem to be able to tell when the windscreen will have sufficient rain on it to warrant a windscreen swipe! I am impressed by how quickly they respond to changes in the heavyness of the rainfall.

I like little gimmicks like that.

Brian

NJ Roadmap · Feb 22, 2007

sriram karhik said:
hi,
i am a new user to this .i am doing my engg. in india and i am in a situation to some project on electrical or electronics.if you have any ideas regarding these(headings,circuitsetc...,) please inform me as soon as possible

Stop poisoning my thread and this forum. Are you a bot?!

Roff · Feb 22, 2007

NJ Roadmap said:
Stop poisoning my thread and this forum. Are you a bot?!

I'm guessing he's a noob to forums, ran across this thread on a search engine, and didn't know the protocol for starting a new thread.

3v0 · Feb 23, 2007

Some ideas.

I would tilt it as mentioned to get the water to run off.

Use a MPU to measure the resistance. That way you could monitor the dry resistance as it changed (cruded up) over time. Use the same info to inform of the need to clean the sensor plate. Determine that a bird has gifted it etc.

Use a small fan or heat the plate to increase response time.

druidmerlin · Mar 1, 2007

A modification to tilting bucket and reed switch --

Use a badminton raquet or similar lightweight frame with a cotton cloth stretched across --- works well in mist application in Leylandii propogation in greenhouses.

Old Brit Maidenhead UK

spuffock · Mar 2, 2007

Put a capacitor in series with it. A PIC will give you a nice AC to drive it.Otherwise it will corrode,gold or no gold.

gramo · Mar 2, 2007

spuffock said:
Put a capacitor in series with it. A PIC will give you a nice AC to drive it.Otherwise it will corrode,gold or no gold.

What value capacitor would you use, and what do you mean by AC?

Hero999 · Mar 2, 2007

AC as in square-wave.

The value of capacitance will depend on the frequency.

gramo · Mar 2, 2007

Hero999 said:
AC as in square-wave.

The value of capacitance will depend on the frequency.

Sorry to delve further into this, just interested of making something similar, but haven’t thought down this road yet.

Why does this stop the corrosion of the tracks, and what frequency/capacitance values would you recommend?

Hero999 · Mar 2, 2007

It probably won't stop corrosion completely but it might slow it down, at least by 50%.

With AC both tracks will corrode equally, unlike DC which will cause the anode only to corrode.

I don't know what frequency to use but higher is probab;y better and the capacitance doesn't matter providing its impedance is low compated to the water.

Cheap(ish) rain sensor?

New Member

New Member

Well-Known Member

New Member

Super Moderator

New Member

Well-Known Member

Super Moderator

Member

New Member

New Member

New Member

Well-Known Member

Coop Build Coordinator

New Member

Member

New Member

Banned

New Member

Banned

Similar threads

Privacy & Transparency

Privacy & Transparency