Pi Pico Learns Morse Code

February 10, 2026 by 2 Comments

When [101 Things] didn’t want to copy Morse code, he decided to build a Pi Pico system to read it for him. On the face of it, this doesn’t seem particularly hard, until you look at the practical considerations. With perfectly timed dots and dashes, it would be trivial. But in real life, you get an audio signal. It has been mangled and mixed with noise and interference as it travels through the air. Then there’s the human on the other end who will rarely send at a constant speed with no errors.

Once you consider that, this becomes quite the project, indeed. The decoder captures audio via the Pi’s analog-to-digital converter. Then it resamples the input, applies an FFT, and converts the output via a complex classification pipeline that includes, among other things, Bayesian decoding. Part of the pipeline makes simple typo corrections. You can see the device do its thing in the video below.

Continue reading “Pi Pico Learns Morse Code” →

Morse Code For China

November 12, 2025 by 45 Comments

It is well known that pictographic languages that use Hanzi, like Mandarin, are difficult to work with for computer input and output devices. After all, each character is a tiny picture that represents an entire word, not just a sound. But did you ever wonder how China used telegraphy? We’ll admit, we had not thought about that until we ran into [Julesy]’s video on the subject that you can watch below.

There are about 50,000 symbols, so having a bunch of dots and dashes wasn’t really practical. Even if you designed it, who could learn it? Turns out, like most languages, you only need about 10,000 words to communicate. A telegraph company in Denmark hired an astronomer who knew some Chinese and tasked him with developing the code. In a straightforward way, he decided to encode each word from a dictionary of up to 10,000 with a unique four-digit number.

Continue reading “Morse Code For China” →

2025 One Hertz Challenge: Learn Morse Code One Second At A Time

August 2, 2025 by 3 Comments

Learning Morse Code is no longer a requirement for HAMs in many jurisdictions, but it’s still a nice skill to have. [I_void(warranties)] wanted to learn, but couldn’t find a trainer that fit his style. What to do but build it yourself? Since we’re in the midst of a challenge, he took up the gauntlet and turned his need to learn Morse into a 1 hertz Morse code game.

In concept it is quite simple: a message beeps out in Morse, with a corresponding LED flash, all in one second. The player then has one second to type think they heard. Get it done fast enough, and a character LCD will tell you if you scored.

The project is based around an Arduino Nano; thanks to easily-available libraries, a PS/2 keyboard can serve as input and a 2×16 LCD as feedback with no real effort expended. For the audible component of the Morse challenge, an 8-ohm speaker is driven right off a pin on the Arduino. We won’t claim this efficient design only took one second to put together, but it probably didn’t take too long.

Of course this trainer, unlike some we’ve seen, only helps you learn to listen to the stream of dots and dashes. None of the others ever tried to fit a One Hertz theme, or [I_void(warranties)]’s particular learning style. For some, decoupling send and receive might be just the ticket to finally learning Morse one second at a time.

2025 Hackaday One Hertz Challenge

The World Morse Code Championship

December 17, 2024 by 54 Comments

If you were in Tunisia in October, you might have caught some of the Morse Code championships this year. If you didn’t make it, you could catch the BBC’s documentary about the event, and you might be surprised at some of the details. For example, you probably think sending and receiving Morse code is only for the elderly. Yet the defending champion is 13 years old.

Teams from around the world participated. There was stiff competition from Russia, Japan, Kuwait, and Romania. However, for some reason, Belarus wins “almost every time.” Many Eastern European countries have children’s clubs that teach code. Russia and Belarus have government-sponsored teams.

Continue reading “The World Morse Code Championship” →

Learning Morse Code With A DIY Trainer

June 22, 2024 by 18 Comments

Morse code, often referred to as continuous wave (CW) in radio circles, has been gradually falling out of use for a long time now. At least in the United States, ham radio licensees don’t have to learn it anymore, and the US Coast Guard stopped using it even for emergencies in 1999. It does have few niche use cases, though, as it requires an extremely narrow bandwidth and a low amount of power to get a signal out and a human operator can usually distinguish it even if the signal is very close to the noise floor. So if you want to try and learn it, you might want to try something like this Morse trainer from [mircemk].

While learning CW can be quite tedious, as [mircemk] puts it, it’s actually fairly easy for a computer to understand and translate so not a lot of specialized equipment is needed. This build is based around the Arduino Nano which is more than up for the job. It can accept input from any audio source, allowing it to translate radio transmissions in real time, and can also be connected to a paddle or key to be used as a trainer for learning the code. It’s also able to count the words-per-minute rate of whatever it hears and display it on a small LCD at the front of the unit which also handles displaying the translations of the Morse code.

If you need a trainer that’s more compact for on-the-go CW, though, take a look at this wearable Morse code device based on the M5StickC Plus instead.

Continue reading “Learning Morse Code With A DIY Trainer” →

Inside America’s Last Morse Code Station

March 8, 2024 by 43 Comments

The Titanic famously (or infamously) used Morse code to call out in distress at the end of its final voyage. Ships at sea and the land-based stations that supported them used Morse code for decades, but with the growing use of satellites, maritime Morse code ended in 1999. With one notable exception. [Saahil Desai] writing in the Atlantic tells the story of  America’s last Morse code station, KPH just north of San Francisco.

In fact, KPH did shut down in 1997 as part of the wind down of Morse code in ocean vessels. But some radio enthusiasts, including [Tom Horsfall] and [Richard Dillman], have brought the venerable station back to life. The radio squirrels, as they call themselves, dutifully send news and weather every Saturday to anyone interested in listening. They also exchange radio traffic, primarily with the SS Jeremiah O’Brien, a World War II-era ship parked nearby. N2FQ visited the station and operated the station on video, which you can see below. Or, check out the tour in the second video, below.

Continue reading “Inside America’s Last Morse Code Station” →

A Toe-Tappin’ Set Of Morse Code Pedals

November 24, 2023 by 15 Comments

What’s the worst thing about traditional Morse keyers? If you ask us, it’s the fact that you have to learn how to do two distinct things with one hand, and switch between them quite quickly and often.

This set of Morse code foot pedals is meant for those who are unable to use traditional methods of keying. It uses a retrofitted wireless keyboard to read Z and X as dit and dah, respectively, and convert the Morse code into text.

[Tevendale_Engineering] started by getting the controller out of the keyboard and figuring out which combination of pads sends Z and X. Then they wired those up with copper tape. The pedals themselves are made from 1/2″-thick wood, foam core board, and Nerf bullets to provide springiness.

There’s no solder here; it’s all copper tape and alligator clip test leads. So if this isn’t your hack for the day, we don’t know what is.

Not so great at Morse code? Here’s a clock that will train you on the numbers, at least.