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bcd
- 31st December 2005, 23:42
Hi All,
I have been looking at the Dallas 1-Wire weather station wind speed and direction sensor as a fun project for the house. Link - <a href="http://www.aagelectronica.com/aag/index.html?target=p_1.html&lang=en-us">Link to the hardware at AAG Electronica</a>

However I don't want to have a PC sitting around to log it all the time.
Has anyone interfaced the Wind speed and direction sensor to a PIC based project?

I am most concerned about the wind speed sensor since it produces one pulse per revolution and I think I'll need a counter that is interrupted every second to allow conversion to a Km per Hour reading ?

I have talked one-wire before, so I am comfortable with the protocol and the commands, just not whether it is possible.

With Thanks, and Happy New Year,

Bill

Mith
- 1st January 2006, 00:05
I have spent much of my free time in the last year building a weather server for my AAG weather station, humidity sensor and TAI-8570 baro pressure sensor. I decided to do this after reading an article in Nuts and Volts where a basic stamp was used to read the temperature, wind speed and direction of a one wire weather station. It didn't do much else but it was interesting. Back to your original question: The wind speed is a counter so you can read a start count then start a timer and read an end count on the timer interrupt. Thats how I chose to do this anyway. The wind direction of the new style weather station is an A/D convertor that reads various fixed resistors based on which reed switches are closed so this is an easy one to deal with. The Nuts and Volts example code shows this done very well.

You can see my weather station here: http://mith.sytes.net

Nuts & Volts 2002 issue: http://www.nutsvolts.com/toc_Pages/TOC_Related_Info/Feb02_Weather.htm

It's done with an 18F252, siteplayer module, 256k epm, DS1629 rtc, 4x16 lcd, 3x4 matrix keypad, TAI weather station, 1910 Humidity sensor & Rain Gauge bucket.

Pete

bcd
- 1st January 2006, 00:37
Thanks Pete,

I am downloading the N&V article for a bit of a look at how its done.

I am glad the v3 AAG kit is now using the A/D to measure the wind direction - I didn't fancy trying to decode the original method that used the series of one-wire switches with reed switches.

Bill.

Mith
- 1st January 2006, 11:20
I did purchase a version 3 one wire weather station from AAG this past year, that's what is connected to my weather server. I still have the original Dallas weather station with the 'ID Tags' for each of the wind directions. I don't think it would have been that difficult to deal with now that I have spent so much time immersed in one wire land. Dallas expected everyone to use their search rom function to 'read' what ID's are available in a given family then determine wind direction based on what came back. That routine is very difficult and takes a lot of processing power to implement. I think the way I would do it would be to go through a series of match rom requests and determine what was available at any given time. It would be far faster than doing a search rom for a specific family.

Somewhere I have a copy of the original Nuts & Volts article that explains the wind speed counter. Remember that the v3 board from AAG has two magnets on the wind speed anemometer vs 1 on the Dallas so you get two ticks per revolution. If you need the article I will try to dig it up.

Let me know if you need anything.

Mith
- 1st January 2006, 11:44
I found the article. Parallax has an archive of nuts and volts columns that pertain to basic stamps.

http://www.parallax.com/dl/docs/cols/nv/vol3/col/nv82.pdf

Pete