Hydreon Optical Rain Sensor

[Pete]

Interesting news....

Steve from Cumulus has released a "test" version of Cumulus with an RS-232 interface to the RG-11.

You can read about it here. I am going to set up second RG-11 with this interface.

http://sandaysoft.com/forum/viewtopi...=7738&start=10

[Michael McSharry]

I have interfaced my two Hydreon units which are located about 15 ft appart and compare the data from a AWS site that is about 3 or 4 miles away. One is with 1-wire using xapmcs1wire and the other is with DS10A/RF using xapmcsRF. I have found the RF and 1-wire results to be very similiar, as expected. The variation from the AWS is just microclimate effects. For those that may experience heavy rainfall the RF may not be able to keep up wth a 0.01 inch/count setting. With settings 0.001 then RF will be too slow and 1-wire or other pulse counting interface will be needed.

[Pete]

From reading about multiple tests using the digital rain guage and Michaels stuff above it appears that the device is a functional replacement for a tipping bucket.

I shifted my connected to a dual counter setup from an mcsXapTemp0X to the mcsXap1-wire application last night. A hodgepodge connection with the 12VDC/5VDC coming from the Temp08 and just the DQ/Ground connected to the 9097.

The Cumulus test beta uses the relay for an RS-232 DTR/DTS setup with the application. Basically just two settings in the Cumulus INI file; one for the serial port and the other for the measurement.

[Pete]

Just an add to the previous note about Cumulus. Steve (author of Cumulus) has added two variables now to Cumulus for two Hydreon Optical Rain Sensors as it appears that everyone has two these days. One variable is just an "its raining" sensor and the other one is for measurements.

The instructions for making an RS-232 interface are here:

http://www.weather-above.com/usbnontiprain.html

The instructions and most current beta are here:

http://sandaysoft.com/forum/viewtopic.php?f=2&t=7341

[Pete]

There appears to be some issue with the RS-232 connection mentioned in previous post. That said there are reported double "tips" maybe occurring.

Here I have redone and added some to my testing using the following:

1 - Davis Vantage Vue - rain reporting to running instance of Cumulus
2 - RG-11 #1 connected to a Hobby Boards dual counter to a Maxim serial 9097 and being read by one instance of mcsxAP 1-wire
3 - RG-11 #2 connected via the RS-232 method above and going to running instance of Cumulus
4 - Connecting old Dallas tipping bucket to same 1-wire network as #2

The above noted I will be comparing this also to local reporting weather stations. No rain in the midwest though to test yet. Today building a PVC standoff for the Dallas Tipping bucket such that I can mount it next to the RG-11's.

[Pete]

Rain today test July 8, 2012

I had a bit of rain today July 8, 2012. Here are my results

Cumulus via Davis Vantage Vue Tipping bucket - 0.13 in
Cumulus via RG-11 - 0.34 in
Dallas Tipping bucket - 0.11 in
RG-11 via 1-wire Dual counter - 0.13 in

[Pete]

We had a bit of rain here yesterday - enough to get some good numbers:

had a bit of rain today July 19, 2012. We are in a drought period here in the midwest. These counts are from midnight.

Here are my results

Cumulus via Davis Vantage Vue Tipping bucket - .28 in
Cumulus via RG-11 - 1.54 in
Dallas Tipping bucket - 0.59 in
RG-11 via 1-wire Dual counter - 0.788 in

I'm beginning to lean toward using the RG-11 as a rain on/off sensor more than a means to measure rain which would work OK.

In the next week or so installing Davis Vantage Vue #2 and a second console. Maybe today putting a graduated cylinder near the two RG-11's.

I wish though that I could get measurements of two Davis Vantage Vue's with one console simultaneously.

[Michael McSharry]

I have observed that the Hydreon works reasonably well for light rainfall, but it does not handle heavy rain very well. Heavy rain is not that common at our location so not much of an issue.

[Pete]

The current Davis Vantage Vue isn't giving me similiar rain numbers so this morning decided to install a second one and a second console next to my test post. I am curious how different the numbers will be if they are different between adjacent rain measuring devices.

[BrunDog]

What's weird is your 2 RG-11's are reading differently. I realize different interfaces, but they should ultimately indicate the same, no?

-BD

[Pete]

Yes the two RG-11's are about 20 inches apart at the same height.

I am at the end of testing the two RG-11's. In August we got enough rain such that I could get some valid numbers.

The two tipping buckets; IE: The Dallas 1-wire and Davis Tipping bucket were always in sync with any rain. The RG-11's numbers were not close to the tipping buckets and the two were reporting different numbers. That said I am also seeing the same conclusions with other folks that have been testing the device.

Many folks have switched to utilizing them for measuring when its raining and the time frame of rain. Other's are using these to measure the number of drops hitting the surface of the RG-11. The device would make a good digital rain sensor for a sprinkler system providing an instant off when its raining.