Rain gauge resetter

[Ed Sowell]

I have an Oregon Scientific wireless rain gauge. An irritating "feature" is battery replacement causes the history to be cleared. If that happens during the rainy season I have to write down the current total and manually add it to all future readings.
It would be nice to have a little box with a button that would run up the rain amount to the previous total.
The rain collector has a tetter totter with a thimble-size bucket at each end. When a bucket gets full the tetter totter flops over, empties the bucket, and starts diverting the collected rain to the other bucket. I believe the circuits in the collector sends an RF signal on each flop. The indoor unit must increment the current total with each signal.

If I'm right about this, one should be able to build a circuit that would emulate the collector. Specifically, a button would send an RF signal at the right frequency on each push or a series of signals if it's held down. I assume can be measured somehow or perhaps obtained from Oregon Sci.

I have a pretty good understanding of circuits and have done a bit of circuit building from schematics for hobby projects over the years, but know nothing about RF.

Any ideas?

 

[Bluejets]

Many of these have a download to pc usb facility......

As far as the rain collection bucket is concerned, it's normally just a simple reed switch and magnet which pulses once each transition.
This is collected in the main receiver along with any other weather data available on the different units and sent every so often( a few minutes) in a data stream and stored in the main unit memory.

Perhaps set up a battery jumper like they use in motor vehicles to retain memory when main battery is replaced. Would be much simpler.

 

[KMoffett]

+1 on the battery jumper technique. Can you post a photo of the battery compartment?

 

[Ed Sowell]

Here's the wanted photo:
http://www.efsowell.us/Photos/Projects/RainGauge/OregonSciRainGuage.jpg

Looks like it wouldn't be easy to attach a jumper battery.

I'm now thinking it shouldn't be too hard to us the existing RF transmitter in the collector. Just use a timer IC or something to emulate the reed switch. Lot's of room in the collector housing and easy to get at than the indoor unit.

 

[bertus]

Hello,

Do you want to break the powersupply from the batteries?
Put a piece of double sided PCB between the battery ans the contact of the battery holder.
Make a couple of wires on the PCB on bothe sides of the piece of PCB.
The wires can be connected to a contact that can break the supply.

Bertus

 

[KMoffett]

Not hard at all. Two pairs of new AA batteries. One two-cell AA battery holder with wires attached. Attach a straight pin on the end of each wire. In the photo either the top or bottom contacts are bridged to place the batteries in series. The other ends are to the circuit. That's the end for the pins. Have your two new pairs of batteries ready to install.
1.Insert the pins under the contacts, noting the correct polarity. Positive to positive and negative to negative.
2.Insert a pair of new batteries in the holder.
3.Pry the old batteries out of the device. Careful not the allow the pins to lose contact.
4.Insert the other pair of new batteries into the device.
5.Remove the pins.
You should not lose any data. I've done this with a scanner to change batteries (No memory battery or super Cap).

 

[Ed Sowell]

.Pry the old batteries out of the device. Careful not the allow the pins to lose contact.

This is the part that looks tricky to me. Where exactly do you poke the pins? Between the metal and the plastic? Looks like a tight fit.

Might give it a try.

 

[AnalogKid]

Another option is a bigger battery. A fat 3.6 V LI cell could last a year. How many battery changes do you do in a year?

ak

 

[KMoffett]

Ed, that's why I suggest thin straight (sewing) pins. Probably between the plastic and the metal. Try a few locations to see where they fit the tightest. Another way is make dummy AA batteries to bring wires out to do what AK suggested. Another way is to attach those wires to the attached circuit. This gives you AC power unless there is a power outage like then there is a thunder storm (with lots of rain). That is the only time the batteries are used.

 

[Ed Sowell]

Did get the pins in. The contacts are actually formed of spring wire. Hope they don't loosen as the springs relax when the batteries are removed.

http://efsowell.us/Photos/Projects/RainGauge/WithJumperPins.jpg

 

[Ed Sowell]

Another option is a bigger battery. A fat 3.6 V LI cell could last a year. How many battery changes do you do in a year?

ak

Actually, they last for at least a year. If I'm on top of the matter I routinely change them in the collector and in the indoor display unit a week or two before the LA area rain-year begins. However, sometimes it's not the battery running down but failing due to corrosion. That happened about 3 weeks ago.

But I don't quite understand what you are you are suggesting. Perhaps running all the time on an external battery pack?

 

[Ed Sowell]

Actually, the indoor display also gets a signal from an outdoor RF temperature sensor. That's how the last battery issue came to my attention.... no more temperature display. And it was corrosion that caused it rather that battery just running down.

 

[AnalogKid]

I don't quite understand what you are you are suggesting. Perhaps running all the time on an external battery pack?

Yes. My read of post #1 was data loss due to battery change. Solution, fewer battery changes. I assume AC power is not available at the remote site ... ?

ak

 

[KMoffett]

From Post #1:"An irritating "feature" is battery replacement causes the history to be cleared." Are we talking about the battery in the indoor data logger or in the remote tilt bucket?
Ken

 

[Ed Sowell]

Yes. My read of post #1 was data loss due to battery change. Solution, fewer battery changes. I assume AC power is not available at the remote site ... ?
ak

No, it's not. The battery in the indoor unit is probably a bigger problem because if it fails the temperature readings don't display. Even there, however, using AC power would require a cord running across a kitchen counter top. Got enough of that already

Also, I don't agree that the problem goes away with fewer battery changes. The reason is you can never tell when it's going to stop working due to a battery problem. For example, the most recent episode it was corrosion at one of the battery contacts.

I think the battery jump would be helpful, but not ideal. Although more complex, the ideal solution in my view is what I proposed initially, an auxiliary device to run up the stored rain total at will at the press of a button.

I do appreciate you input though, and that of others here.

 

[Bluejets]

The unit i have here is rechargeable AA and a small solar panel adjacent to the sensors.
Even so, the data there is not stored for more than a couple of minutes where it then gets sent out to the main unit for long haul storage.

 

[KMoffett]

"using AC power would require a cord running across a kitchen counter top. Got enough of that already"
If the indoor unit is battery powered, why not just move it to a more convenient location near an AC outlet to allow an AC/Battery alternate power source?

 

[Ed Sowell]

The unit i have here is rechargeable AA and a small solar panel adjacent to the sensors.
Even so, the data there is not stored for more than a couple of minutes where it then gets sent out to the main unit for long haul storage.

So you have a rain gauge something like mine? Brand, Model? Just curious.

You're right about the storage not being at the outdoor unit. I seem to have not been clear about the this, but the battery in question is the one for the indoor unit. As I recall if the outdoor unit battery fails it can be replaced without resetting the indoor unit. But, the thing is if I forget to replace the battery in the outdoor unit before the rainy season comes it may well go out later and I won't know until it starts to rain. Therefore the total will be off by the amount for that storm or squall.

 

[Ed Sowell]

If the indoor unit is battery powered, why not just move it to a more convenient location near an AC outlet to allow an AC/Battery alternate power source?

Not a bad idea. It's on the "window box" shelf behind the kitchen sink. The reason it's there is because an earlier model was wired and it was an easy wire pull there. It's probably a bad place because it may be the reason for battery contact corrosion.

I'll see if I can find another place with good RF... pour a little water in the collector and see if it runs up the total. BTW, I've sometimes thought about that as a way to run up the total after a reset. Way too simple for me, though. My friends sometimes accuse me of always finding the most difficult way of fixing things.

It's interesting to me that I came her for electronic advice and everyone wants to find a non-electronic fix.

 

[KMoffett]

Not me!