Old Rabbit Ears Optimized For Weather Satellite Downlink

July 10, 2017 by Dan Maloney 10 Comments

Communicating with a satellite seems like something that should take a lot of equipment. A fancy antenna and racks full of receivers, filters, and amplifiers would seem to be the entry-level suite of gear. But listening to a weather satellite with an old pair of rabbit ears and an SDR dongle? That’s a thing too.

There was a time when a pair of rabbit ears accompanied every new TV. Those days are gone, but [Thomas Cholakov (N1SPY)] managed to find one of the old TV dipoles in his garage, complete with 300-ohm twinlead and spade connectors. He put it to work listening to a NOAA weather satellite on 137 MHz by configuring it in a horizontal V-dipole arrangement. The antenna legs are spread about 120° apart and adjusted to about 20.5 inches (52 cm) length each. The length makes the antenna resonant at the right frequency, the vee shape makes the radiation pattern nearly circular, and the horizontal polarization excludes signals from the nearby FM broadcast band and directs the pattern skyward. [Thomas] doesn’t mention how he matched the antenna’s impedance to the SDR, but there appears to be some sort of balun in the video below. The satellite signal is decoded and displayed in real time with surprisingly good results.

Itching to listen to satellites but don’t have any rabbit ears? No problem — just go find a cooking pot and get to it.

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Tweet The Power Of Lightning!

July 8, 2017 by James Hobson 15 Comments

How quickly would you say yes to being granted the power to control lightning? Ok, since that has hitherto been impossible, what about the lesser power of detecting and tweeting any nearby lightning strikes?

Tingling at the possibility of connecting with lightning’s awesome power in one shape or another, [Hexalyse] combined AMS’s lightning sensor chip with a Raspberry Pi and a whipped up a spot of Python code to tweet the approach of a potential storm. Trusting the chip to correctly calculate strike data, [Hexalyse]’s detector only tweets at five minute intervals — because nobody likes a spambot — but waits for at least five strikes in a given time frame before announcing that a storm’s-a-brewing. Each tweet announces lightning strike energy, distance from the chip, and number of strikes since the last update. If there haven’t been any nearby lightning strikes for an hour, the twitter feed announces the storm has passed.

It just so happened that as [Hexalyse] finished up their project, a thunderstorm bore down on their town of Toulouse, France putting their project to the test — to positive success. Check out the detector’s tweets (in French).

We recently featured another type of lightning detector that auto-deploys a lightning rod once a storm arrives!

Detect Lightning Strikes With Audio Equipment

June 10, 2017 by Bryan Cockfield 21 Comments

One of the driving principles of a lot of the projects we see is simplicity. Whether that’s a specific design goal or a result of having limited parts to work with, it often results in projects that are innovative solutions to problems. As far as simplicity goes, however, the latest project from [153armstrong] takes the cake. The build is able to detect lightning using a single piece of equipment that is almost guaranteed to be within a few feet of anyone reading this article.

The part in question is a simple, unmodified headphone jack. Since lightning is so powerful and produces radio waves in many detectable ranges, it doesn’t take much to detecting a strike within a few kilometers. Besides the headphone jack, a computer with an audio recording program is also required to gather data. (Audio is often used as a stand-in for storing other types of data; in this case, RF information.) [153armstrong] uses a gas torch igniter as a stand-in for a lightning strike, but the RF generated is similar enough to test this proof-of-concept. The video of their tests is after the break.

Audacity is a great tool for processing audio, or for that matter any other data that you happen to be gathering using a sound card. It’s open source and fairly powerful. As far as lightning goes, however, it’s possible to dive far down the rabbit hole. Detecting lightning is one thing, but locating it requires a larger number of weather stations.

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Lights Out In Québec: The 1989 Geomagnetic Storm

April 10, 2017 by Dan Maloney 56 Comments

I found myself staring up at the sky on the night of March 13, 1989, with my girlfriend and her parents in the backyard of their house. The sky was on fire, almost literally. Red and pink sheets of plasma streamed out in a circle from directly overhead, with blue-white streaks like xenon flashes occasionally strobing across the sky. We could actually hear a sizzling, crackling sound around us. The four of us stood there, awestruck by the aurora borealis we were lucky enough to witness.

At the same time, lights were winking out a couple of hundred miles north in Québec province. The same solar storm that was mesmerizing me was causing fits for Hydro-Québec, the provincial power authority, tripping circuit breakers and wreaking havoc. This certainly wasn’t the first time the Sun threw a fit and broke systems on Earth, but it was pretty dramatic, and there are some lessons to be learned from it and other solar outbursts.

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Stephen Hawking Forecasts The Weather

March 8, 2017 by Bryan Cockfield 15 Comments

Stephen Hawking, although unable to speak himself, is immediately recognizable by his voice which is provided through a computer and a voice emulator. What may come as a surprise to some is that this voice emulator, the Emic2, has been used by many people, and is still around today and available for whatever text-to-speech projects you are working on. As a great example of this, [TegwynTwmffat] has built a weather forecasting station using an Emic2 voice module to provide audible weather alerts.

Besides the unique voice, the weather center is a high quality build on its own. An Arduino Mega 2560 equipped with a GPRS module is able to pull weather information once an hour. After the voice module was constructed (which seems like a project in itself) its relatively straightforward to pass the information from the Arduino over to the module and have it start announcing the weather. It can even be programmed to sing the weather to you!

All of the code that [TegwynTwmffat] used to build this is available on the project site if you’re curious about building your own Emic2 voice system. It’s also worth noting that GPRS is available to pretty much anyone and is a relatively simple system to start using to do things like pull weather information from, but you could also use it to roll out your own private cell phone network with the right equipment and licensing.

See The Weather At A Glance With This WiFi Wall Mounted Display

March 4, 2017 by James Hobson 6 Comments

Whether you’re lodged in an apartment with a poor view of the sky like [Becky Stern] or are looking for an at-a-glance report of the current weather, you might consider this minimalist weather display instead of checking your computer or your phone every time you’re headed out the door.

The first order of business was to set up her Feather Huzzah ESP8266 module. [Becky] started with a blink test to ensure it was working properly. Once that was out of the way, she moved on to installing a few libraries. Temperature data fetched by an IFTTT feed is displayed on a seven-segment display, while additional feeds separately retrieve information for each basic weather type: sunny, overcast, rain, snow.

All it took to create the sleek display effect was a few pieces of cardboard inside a shadow box frame, a sheet of paper as a diffuser, and twelve Neopixel RGB LEDs hidden inside. Trimming and securing everything in place as well as notching out the back of the frame for the power cable finished the assembly. Check out the build video after the break.

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Old Motor Donates Rotor For Coaxial Wind Vane And Anemometer

January 12, 2017 by Dan Maloney 9 Comments

Problem: build a combined anemometer and wind vane where the pivots for both sensors are coaxial. Solution: turn an old universal motor into a step-wise potentiometer for the wind vane, and then pull a few tricks to get the whole thing assembled.

We have to admit that when we first saw [Ajoy Raman]’s Instructables post, we figured that he used a universal motor to generate a voltage from the anemometer. But [Ajoy]’s solution to the coaxial shafts problem is far more interesting than that. A discarded universal motor donated its rotor and bearings. The windings were stripped off the assembly leaving nothing but the commutator. 1kΩ SMD resistors were soldered across adjacent commutator sections to form a series resistance of 22kΩ with taps every 1k, allowing 0 to 2.2V to be read to the ADC of a microcontroller depending on the angle of the vane.

As clever as that is, [Ajoy] still had to pull off the coaxial part, which he did by drilling out the old motor shaft from one end to the other using just a drill press. The anemometer shaft passes through the hole in the shaft and turns a small DC motor to sense wind speed.

There might have been other ways to accomplish this, but given the constraints and the low cost of this solution, our hats are off to [Ajoy]. We’re a little concerned with that motor used for the anemometer, though. It could result in drag when used as a generator. Maybe a better solution would be a Hall-effect sensor to count rotations of a hard drive rotor.

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