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Oww works with three types of weather station:
Originally the weather station was designed and manufactured by Dallas Semiconductor. Since they stopped selling it, Automatizacion Aplicada a Gasolineras, a Mexican engineering company who manufacture several interesting 1-wire products, announced the availability of their version of the 1-wire weather station. They have since replaced this with a newer version (‘Version 3’) with an improved design, which Oww supports also. AAG have held the original Dallas price ($79 US), but currently do not list postage outside of North America. Someone has told me it is $41 to the UK – I expect there will be VAT on top of that.
There is a company selling the AAG kit in the UK. They are Revolution Education Ltd – see their online catalogue. The weather station is under “Educational Systems”.
The version 3 weather station, from
AAG:
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 1-wire weather station on test |
There was also a ‘tipping bucket’ rain gauge available from Dallas. Made of a sturdy plastic moulding, this can attach to a mast. However, this is no longer available; but AAG have conversion kits for the non-one-wire Davis rain gauge.
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For a while Dallas had a kit for a relative humidity sensor. This was discontinued, but you can build one yourself, based on information from Dallas. AAG have two different forms of their TAI8540 module. The H3-R1-A humidity board is available from Hobby Boards in kit form or assembled. Please note that solar/humidity variants from Hobby Boards may only be assigned to Oww as either a humidity sensor or a solar sensor – not both. From version 0.81.6 Oww support the DS1923 hygrochron iButton, in forced conversion mode (i.e. live data, not missions). |
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The old Dallas kit could also be built up as a solar radiation monitor. The S3-R1-A solar radiation detector is available from Hobby Boards in kit form or assembled. Please note that solar/humidity variants from Hobby Boards may only be assigned to Oww as either a humidity sensor or a solar sensor – not both. |
Oww can read from AAG TAI-8570 barometers.
Many thanks to AAG for supplying a sample TAI-8570. |
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Oww can also read barometric pressure from DS2438-based barometers. Various do-it-yourself designs have been developed. Follow these links for more information:
Many thanks to Simon Atkin for donating a built barometer module (pictured to the right). The BB4-R3 Bray Barometer is available from Hobby Boards in kit form or assembled. |
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The anemometer and rain gauge both count events (cup rotations or bucket tips) using a counter chip. Oww can read from extra “general purpose” counters as well. One example of a possible use is a lightning detector.
The DC2-R1 dual counter board is available from Hobby Boards in kit form or assembled.
The LD3-R2 lightning detector is available from Hobby Boards in kit form or assembled.
LCD interfaces based on the DS2408 parallel i/o chip may be addressed by Oww, to display weather data. Two types of interface are suuported (they use the two output nibbles differently):
Actually I don't have either of these myself. Instead I made myself a small PCB with headers for both configurations from their published schematics.
See also the iButton LinkHub, below.
Oww now supports DS2409-based “hubs”, as described by Simon Atkin at www.simat.enta.net
The computer running Oww has to communicate with the weather station devices on the 1-wire net, using a 1-wire net adaptor. Several types of adaptor are available, the most common of which are supported by Oww:
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| 1-wire Adaptors (left) DS9097U, (middle) The LINK, and (right) DS9490R |
| OS | USB Supported? | Notes |
|---|---|---|
| RISC OS | No | No support planned |
| Linux | Yes | See note about USB configuration |
| BSD | Maybe | Should work, but I've not succeeded yet |
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| The iButtonLink LinkHub |
As well as full-blown computers running Linux/BSD or RISC OS, I now have Oww running on the Linksys NSLU2 network storage unit, or Slug. This is an XScale-based unit, running Linux, intended to provide a home server to Windows machines, by using Samba. There is a group of hackers at www.nslu2-linux.org who have greatly expanded its functionality. It is equiped with two USB ports. I'm using one for a USB2 external hard disk (in principle it could work with just a USB flash drive instead) and the other for a DS9490R 1-wire adaptor. I have owwnogui logging to the disk, and uploading to Weather Underground. |
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Some advantages of using this device over a normal PC are:
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You will need to follow the instructions on the Web site to convert your slug to unslung.
Then you should log in as root, and install the oww package:
ipkg install oww
Start off with owwnogui in interactive mode,
so that you can assign the devices:
owwnogui -i
You will need to use the interactive commands a to select the adaptor port to use, as the default /dev/ttyS0( isn't present on the Slug.
Instead, you will want to choose either a USB serial port connected to a DS9097 (or similar) or a DS9490 USB 1-wire adaptor.
To add a USB serial adaptor to the slug you'll need to install some
extra kernel module packages. To find out which, under Linux look at the output of the dmesg command,
it should give you some clues. Mine ends with
"Prolific PL2303 USB to serial adaptor driver".
Under Windows you can try looking at the
Device Manager entry for the COM port.
Mine says "Prolific USB-to-Serial Comm Port".
So clearly mine uses the Prolific chip! This is a common one.
Next you need to install the required kernel modules. You'll need to:
ipkg install kernel-module-usbserial
Then you'll need to hardware-specific module:
ipkg install kernel-module-pl2303
Possible alternatives are
kernel-module-belkin-sakernel-module-ftdi-siokernel-module-mct-u232For testing you can load these by hand:
insmod usbserial
insmod pl2303
The module should then claim the port (dmesg reports ...PL-2303 converter now attached to ttyUSB0...).
Now you can run owwnogui in interactive mode (owwnogui -i)
and set the driver to the USB serial port:
devices driver /dev/ttyUSB0
Now carry on with the devices setup, below, but to make
the modules load automatically at startup you will then need
to create a script. I made /opt/etc/init.d/S79usbserial
(it needs to have a name that comes before S80oww so that it
runs first). The contents are just the insmod lines
for your setup.
Be sure to make the file executable (chmod a+xr /opt/etc/init.d/S79usbserial).
If you're using a DS9490 adaptor you just need to run owwnogui in interactive mode (owwnogui -i) and select the USB driver.
devices driver USB
Next you can search for sensors and assign them to devices. Be sure to save your devices file at the end. Still in interactive mode, enter the following:
search
assign
save devices
Chances are you'll need to reassign some sensors, as some of Oww's guesses
will likely be wrong.
Enter save devices again when the output makes sense.
You can exit with the quit command.
Then run it in daemon mode with
the init.d script (this will happen automatically at boot):
/opt/etc/init.d/S80oww
Feel free to buy a slug (or anything else) through my Amazon links!
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