Hacklet 69 – Morse Code Projects

With over 160 years of history under its belt, Morse code is by far the oldest digital signaling system known to man. Originally developed for telegraph systems, [Samuel Morse’s] code has been sent over wires, via radio, and even with flashes of light. Hackers, makers and engineers have been working with Morse code throughout history. For many years, simple code keys and practice oscillators were the “hello world” of hobby electronics. In fact, a company which started out selling a Morse key has gone on to become one of the largest electronic component distributors in the world. The company still bears the name of that project: Digi-Key. This week’s Hacklet is all about some of the best Morse code projects on Hackaday.io!

key1We start with [voxnulla] and Morse key HID + ugly hack. [voxnulla] found an old key at his favorite thrift store. It was dusty, greasy, and for some reason had been painted hospital green. Once the paint and grime were removed, and the original wooden plate restored, the key actually looked pretty good. [Voxnulla] then decided to turn it into a USB Human Interface Device (HID), emulating the keyboard of his computer. An Arduino converts Morse code characters tapped at the key into keystrokes over USB. As [voxnulla] knows, when butterflies aren’t available, real programmers drive vim with a Morse key!

code2Next up is [Voja Antonic] with Daddy, I don’t have the key. If you didn’t read [Voja’s] article about Hacking the Digital and Social System, check it out! Many apartments have an intercom system where you have to “buzz” someone in, activating a solenoid lock in the door. [Voja] inserted a Microchip PIC12 series microcontroller between the speaker and the unlock button. All a user has to do is tap out the right Morse code password on the call button in the lobby. If the code is accepted, the PIC unlocks the door, and you’re in!


morseterminal[kodera2t] took things into the digital age with Stand-alone Tiny Morse code encoder/decoder. This project grew out of his general purpose Portable tiny IoT device project. [kodera2t] rolled his own Arduino-compatible board for this project. The tiny ATmega1284 powered computer allows him to encode and decode Morse code. A smartphone-sized keyboard and a lilliputian OLED display serve as the user interface, while rotary encoder allows for variable code speed. You can even “tap” Morse out on one of the tactile buttons!


morselightFinally, we have [Yannick (Gigawipf)] with Portable (morsing) 100W led flashlight. 100 watt LEDs have gotten quite cheap these days, and they’re perfect when you absolutely, positively have to blind everyone around you. These LEDs can also be switched on and off quickly, which makes them perfect for Morse code. In years past, mechanical shutters had to be used to perform the same feat. [Yannick] used a 5000mAh 5S Zippy Li-Po to supply electrons to this hungry beast, while a 600 Watt constant current boost converter keeps that power under control. An Arduino running Morse code converter software controls the boost convert and LED.  [Yannick] uses his computer to send a message over the Arduino’s serial link, and the light does the rest, flashing out the message for all to see.

If you want more Morse goodness, check out our brand new Morse code project list! My Morse is a bit rusty, so if I wasn’t able to copy your transmission and missed your project, don’t hesitate to drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

$40 Antenna Analyzer with Arduino and AD9850

If you are a hacker, you might consider ham radio operators as innovative. Most people, however, just see them as cheap. So it is no surprise that hams like [jmharvey] will build an antenna analyzer from a DDS module and an Arduino instead of dropping a few hundred dollars on a commercial unit. As he points out, you probably only need an analyzer for a day or two while you set up an antenna. Unless you are a big time antenna builder, the unit will then sit idle on the shelf (or will wind up on loan to hams even cheaper than you are).

The design is rooted in another proven design, but changed to take advantage of parts he happened to have on hand. Although the build is on a universal circuit board, [jmharvey] used Eagle to lay out the circuit as though it were a PCB. Since placement can be important with an RF circuit, this isn’t a bad idea. It’s always easier to move stuff around on the screen than on the perf board.

Since this is a no frills, unit, you are expected to grab the output from the Arduino and manually put it in a spreadsheet to plot the results. There is another version of the Arduino code that drives an OLED screen, although you still need a PC to kick the process off. One interesting feature of the Arduino code is how it deals with the nonlinear nature of the diodes used in the circuit. After plotting the values with known loads, [jmharvey] broke the diode operation into three regions and used different equations for each region. Even so, he warns that readings higher than 1:1 VSWR are only accurate to 10% or 20% – still good enough for ham shack use.

If you want an antenna analyzer for $40 (or less, if you have a good stock of parts) this looks like a worthwhile project. If, however, you want to repurpose it to Rickroll your neighbor’s AM radio, you might want to go with the commercial unit.

Click past the break to see the analyzer in action.

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Visualizing RF Standing Waves

Standing waves are one of those topics that lots of people have a working knowledge of, but few seem to really grasp. A Ham radio operator will tell you all about the standing wave ratio (SWR) of his antenna, and he may even have a meter in the shack to measure it. He’ll know that a 1.1 to 1 SWR is a good thing, but 2 to 1 is not so good. Ask him to explain exactly what a standing wave is, though, and chances are good that hands will be waved. But [Allen], a Ham also known as [W2AEW], has just released an excellent video explaining standing waves by measuring signals along an open transmission line.

[Source: Wikipedia]
[Source: Wikipedia]
To really understand standing waves, you’ve got to remember two things. First, waves of any kind will tend to be at least partially reflected when they experience a change in the impedance of the transmission medium. The classic example is an open circuit or short at the end of an RF transmission line, which will perfectly reflect an incoming RF signal back to its source. Second, waves that travel in the same medium overlap each other and their peaks and troughs can be summed. If two waves peak together, they reinforce each other; if a peak and a trough line up, they cancel each other out.

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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 hackaday.io, the project can be found here.

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Pico Space Balloon Circumnavigates the Globe, Twice

We’ve reported on “space” balloons before. Heck, some of us have even launched a few. Usually they go way up in the air, take some cool pictures, and land within driving (and retrieving) distance the same afternoon. You get often amazing photos and bragging rights that you took them for the low, low price of a really big helium balloon and a fill.

But what if you shrunk everything down? Over the last few years, [Andy, VK3YT] has been launching ever smaller and lighter balloons with very low power ham radio payloads. So no camera and no photos, but the payback is that he’s launching payloads that weigh around thirteen grams complete with GPS, radio, solar cell, and batteries. They can stay up for weeks and go really far. We’d love to see some construction details beyond the minimalistic “Solar powered party balloon, 25mW TX”. But that about sums it up.

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The Alexanderson Transmitter: Very-low Frequency Radio Rides Again!

Is your ham radio rig made of iron and steel? Is it mechanically driven? Classified as a World Heritage Site? We didn’t think so. But if you’d like to tune in one that is, or if you’re just a ham radio geek in need of a bizarre challenge, don’t miss Alexanderson Day 2015 tomorrow, Sunday, June 28th

The Alexanderson Transmitter design dates back to around 1910, before any of the newfangled tube technology had been invented. Weighing in at around 50 tons, the monster powering the Varberg Radio Station is essentially a high-speed alternator — a generator that puts out 17.2 kHz instead of the 50-60 Hz  that the electric companies give us today.

Most of the challenge in receiving the Alexanderson transmitter broadcasts are due to this very low broadcast frequency; your antenna is not long enough. If you’re in Europe, it’s a lot easier because the station, SAQ, is located in Sweden. But given that the original purpose of these behemoths was transcontinental Morse code transmission, it only seems sporting to try to pick it up in the USA. East Coasters are well situated to give it a shot.

And of course, there’s an app for that. The original SAQrx VLF Receiver and the extended version both use your computer’s sound card and FFTs to extract the probably weak signal from the noise.

We scouted around the net for an antenna design and didn’t come up with anything more concrete than “few hundred turns of wire in a coil” plugged into the mic input.  If anyone has an optimized antenna design for this frequency, post up in the comments?

Thanks [Martin] for the tip!

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!

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