Posts with «amateur radio» label

Tiny Radio Tracks Your Balloons

The name of the game in rocketry or ballooning is weight. The amount of mass that can be removed from one of these high-altitude devices directly impacts how high and how far it can go. Even NASA, which estimates about $10,000 per pound for low-earth orbit, has huge incentives to make lightweight components. And, while the Santa Barbara Hackerspace won’t be getting quite that much altitude, their APRS-enabled balloon/rocket tracker certainly helps cut down on weight.

Tracksoar is a 2″ x .75″ x .5″ board which weighs in at 45 grams with a pair of AA batteries and boasts an ATmega 328P microcontroller with plenty of processing power for its array of on-board sensors. Not to mention everything else you would need like digital I/O, a GPS module, and, of course, the APRS radio which allows it to send data over amateur radio frequencies. The key to all of this is that the APRS module is integrated with the board itself, which saves weight over the conventional method of having a separate APRS module in addition to the microcontroller and sensors.

As far as we can see, this is one of the smallest APRS modules we’ve ever seen. It could certainly be useful for anyone trying to save weight in any high-altitude project. There are a few other APRS projects out there as well but remember: an amateur radio license will almost certainly be required to use any of these.

Filed under: radio hacks

HamShield Puts Your Arduino On The Radio

Anybody can grab a USB TV tuner card and start monitoring the airwaves, but to get into the real meat of radio you’ll need your amateur radio license. Once you have that, the bandwidth really opens up… if you can afford the equipment. However, [spaceneedle] and friends have dramatically lowered the costs while increasing the possibilities of owning a radio by creating this ham radio shield for the Arduino.

The HamShield, is a versatile shield for any standard Arduino that allows it to function like an off-the-shelf radio would, but with a virtually unlimited number of functions. Anything that could be imagined can be programmed into the Arduino for use over the air, including voice and packet applications. The project’s sandbox already includes things like setting up mesh networks, communicating over APRS, setting up repeaters or beacons, monitoring weather stations, and a whole host of other ham radio applications.

HamShield operates on a wide range of frequencies and only uses a 250 mW amplifier. The power draw is small enough that the HamShield team operated it from a small solar panel, making it ideal for people in remote areas. The project is currently gathering funding and has surpassed their goal on Kickstarter, branding itself appropriately as the swiss army of amateur radio. The transceiver seems to be very robust, meaning that the only thing standing in the way of using this tool is simply writing the Arduino code for whatever project you want to do, whether that’s as a police scanner or even just a frequency counter. And if you want to follow along on, the project can be found here.

Filed under: Arduino Hacks, radio hacks

APRS Tracking System Flies Your Balloons

Looking for a way to track your high-altitude balloons but don’t want to mess with sending data over a cellular network? [Zack Clobes] and the others at Project Traveler may have just the thing for you: a position-reporting board that uses the Automatic Packet Reporting System (APRS) network to report location data and easily fits on an Arduino in the form of a shield.

The project is based on an Atmel 328P and all it needs to report position data is a small antenna and a battery. For those unfamiliar with APRS, it uses amateur radio frequencies to send data packets instead of something like the GSM network. APRS is very robust, and devices that use it can send GPS information as well as text messages, emails, weather reports, radio telemetry data, and radio direction finding information in case GPS is not available.

If this location reporting ability isn’t enough for you, the project can function as a shield as well, which means that more data lines are available for other things like monitoring sensors and driving servos. All in a small, lightweight package that doesn’t rely on a cell network. All of the schematics and other information are available on the project site if you want to give this a shot, but if you DO need the cell network, this may be more your style. Be sure to check out the video after the break, too!

Filed under: radio hacks

Converting Morse Code to Text with Arduino

Morse code used to be widely used around the globe. Before voice transmissions were possible over radio, Morse code was all the rage. Nowadays, it’s been replaced with more sophisticated technologies that allow us to transmit voice, or data much faster and more efficiently. You don’t even need to know Morse code to get an amateur radio license any more. That doesn’t mean that Morse code is dead, though. There are still plenty of hobbyists out there practicing for the fun of it.

[Dan] decided to take a shortcut and use some modern technology to make it easier to translate Morse code back into readable text. His project log is a good example of the natural progression we all make when we are learning something new. He started out with an Arduino and a simple microphone. He wrote a basic sketch to read the input from the microphone and output the perceived volume over a Serial monitor as a series of asterisks. The more asterisks, the louder the signal. He calibrated the system so that a quiet room would read zero.

He found that while this worked, the Arduino was so fast that it detected very short pulses that the human ear could not detect. This would throw off his readings and needed to be smoothed out. If you are familiar with button debouncing then you get the idea. He ended up just averaging a few samples at a time, which worked out nicely.

The next iteration of the software added the ability to detect each legitimate beep from the Morse code signal. He cleared away anything too short. The result was a series of long and short chains of asterisks, representing long or short beeps. The third iteration translated these chains into dots and dashes. This version could also detect longer pauses between words to make things more readable.

Finally, [Dan] added a sort of lookup table to translate the dots and dashes back into ASCII characters. Now he can rest easy while the Arduino does all of the hard work. If you’re wondering why anyone would want to learn Morse code these days, it’s still a very simple way for humans to communicate long distances without the aid of a computer.

Filed under: Arduino Hacks