Ultrasonic anemometer for an absurdly accurate weather station

With his meteorological interests, [Carl] builds weather stations. Temperature and humidity sensors are a dime a dozen, but with his DIY ingenuity, [Carl] has built some very interesting and complicated devices. The latest of which is an ultrasonic wind sensor that uses the time of flight of ultrasonic pulses to detect how fast the wind is blowing.

[Carl]’s sensor uses four ultrasonic transducers aligned to North, South, East, and West to detect the wind speed. By measuring the time it takes an ultrasonic pulse to travel between the sensors indoors, Subtracting the in-situ measurement gives him the time of flight for each axis, and thus the wind speed.

It’s an impressive display of engineering that comes with an amazingly detailed design report. After three months of operation, [Carl] has found his ultrasonic anemometer is better than the traditional mechanical ‘egg-cup’ anemometer at measuring low wind speeds. The only real problem with the build is the fact the design makes a great bird perch, but some fine steel wire quickly corrected that problem.

Converting a weather station kit for wireless data harvesting

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Everyone loves getting something you can play with as a Christmas gift. [Thomas] was the lucky recipient of an Elektor USB weather station kit. But the fun didn’t end once he had assembled everything. He went on to hack the device for wireless data collection.

Shown above is the weather station board connected to the transmitter. The red board with a tiny antenna to the right is a Rovio RN-VX module. It is capable of transmitting serial data to its twin on the receiving end of the setup. The weather station is pretty easy to connect to the transmitter since it feeds serial data to an FTDI USB chip. [Thomas] simply connected power and ground, then added a jumper from the board’s TX pin to the Rovio’s RX pin. The receiving end uses a serial-to-USB converter — getting a signal for its RX pin from the TX pin on the Rovio receiver board.

We know from other projects that these radio modules can connect to a WiFi AP. Perhaps a future revision of [Thomas’] hack will allow the weather station to communicate with his server over the network, doing away with the need for a standalone receiver.

Weather station graphs history on webpage

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Kudos go out to [Jose] for his work getting so many different components to talk to each other in this Arduino weather station that using a Raspberry Pi to display the data online.

The components shown above make up the sensor package. There’s an Arduino with a custom shield that interfaces the barometric pressure sensor, real-time clock chip, a digital temperature sensor, and a humidity sensor. On top of that shield is an XBee shield that lets this push data back to the base station. [Jose] also rolled in an LCD character display and a few buttons so that the user may view weather data without heading to the web.

A Raspberry Pi board makes up the other half of the XBee pair. It harvests the incoming data from the radio module using a USB to Serial converter cable. You can see the data log on the webpage linked above. Just choose the “LIVE” menu option and click on “Daily” to get a better overview of humidity and pressure changes.

Hackaday Links: December 13th, 2012

Cardboard box computer

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[Alistair] chapman had a Laptop with a broken screen sitting in his parts bin. He knew he had an LCD panel on hand that would probably work with it, but it wouldn’t fit in the case. His solution was to transplant all the computer parts into a cardboard box from a motherboard.

This violin is garbage

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The kids in this orchestra live in a villiage built on top of a landfill. But they make the most out of what they have. This orchestra is composed of instruments built from garbage and they seem to work pretty well. [Thanks Bruce]

More LED mystery puzzles

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[Henryk] is at it again. He puts together some very impressive circuits that play tricks on your engineering mind. His latest is three LEDs in series. Look closely and you’ll see they’re not performing as expected. Watching the solution to one of his previous puzzles will help you figure out how he’s doing it. His work is simply amazing.

Netbook framed as a dedicated weather station

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Not wanting to get rid of old but still working hardware, [Retro Toaster] built a dedicated weather station by mounting the screen, keyboard, and track pad in a picture frame.

Current and voltage testing your USB projects

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This dev board is a pass-through for USB devices. It makes voltage and current testing your device quite simple.

An Extemely Unique Weather Display

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Most home weather displays use an LED screen or other moderately interesting methods of showing you what’s going on outside. The [Tempescope], however, takes an entirely different route, actually recreating a tiny weather environment on your bookshelf!

This active weather device is controlled via an Arduino as well as a pump, ultrasound diffuser, and other assorted components connected to a computer. It was originally meant to display, or more accurately recreate (precreate?) tomorrow’s weather. What is even more interesting is that using [World Weather] software, it’s able to simulate the weather on any place on earth.

Early in this article [Ken] lists the art of [bonsai] as one of his inspirations. He’s open to suggestions as to how to expand this device, which can be seen after the break. We (I at least) would think it was awesome if there was actually a bonsai tree in the environment in keeping with its influences. Certainly our readers can give him some feedback as well! Continue reading “An Extemely Unique Weather Display”

Building a steam punk style time and weather display

This is [Pierre Cauchois’] digital weather display. Since weather displays are ubiquitous in this day of smart phones in every pocket he went out of his way to give it a unique look. He started with a wooden voltmeter case, swapping the ancient display for a modern LCD screen.

He used Gadgeteer components for the retrofit. The images for the LCD are stored on an SD card and displayed on demand. Since the digital bezel will be the same no matter what the time or environmental conditions [Pierre] used the power of the .NET framework that drives the system. He made up an image using magenta for all of the dial openings. This way a sprite can be used just for the changing numbers, weather icon, and graphing area.

Looking at all that went into coding the project we think the Gadgeteer components are perfect for those that are well-versed in upper-level languages and don’t really want to deal with low-level microcontroller issues.

[Thanks George]

Extending the range of wireless weather stations with walkie talkies

[Roel] wanted to put a wireless weather station in his greenhouse. Even though the weather station was supposed to transmit over fairly long distances, the geometry of his back yard and a few stone walls killed the radio signal even after putting a good antenna on the receiving side of his wireless weather station setup. Wanting to get his weather station working, [Roel] did the sensible thing and built a packet radio setup out of a pair of walkie talkies, greatly increasing the range of his weather station.

This build comes after [Roel] spent a great deal of time reverse engineering the wireless protocol of his Thierry Mugler weather station. With a little bit of code, [Roel] is able to get the current temperature and humidity reading into his Linux box. This system relies on the transmitter inside the weather station, so the system falls apart over any sufficiently large distance.

To increase the range of his weather station, [Roel] took his existing hardware and added a pair of inexpensive FRS walkie talkies. The build uses the hardware from his previous build to get the radio data from the weather station. This data is sent over to an ATmega88 where it’s converted to packet radio and sent over the walkie-talkie. On the receiving side, the output of a second walkie-talkie is piped into the Linux soundmodem app (link, but it’s down as of this writing) where it’s decoded. Sending the received data to gnuplot makes a very nice graph of the temperature and humidity.

[Roel] put the code for both the tx and rx sides of the build up on his build page. Very nice work that uses very inexpensive hardware.