Morse Code Clock For Training Hams

It might seem antiquated, but Morse code still has a number of advantages compared to other modes of communication, especially over radio waves. It’s low bandwidth compared to voice or even text, and can be discerned against background noise even at extremely low signal strengths. Not every regulatory agency requires amateur operators to learn Morse any more, but for those that do it can be a challenge, so [Cristiano Monteiro] built this clock to help get some practice.

The project is based around his favorite microcontroller, the PIC16F1827, and uses a DS1307 to keep track of time. A single RGB LED at the top of the project enclosure flashes the codes for hours in blue and minutes in red at the beginning of every minute, and in between flashes green for each second.

Another design goal of this build was to have it operate with as little power as possible, so with a TP4056 control board, single lithium 18650 battery, and some code optimization, [Cristiano] believes he can get around 60 days of operation between charges.

For a project to help an aspiring radio operator learn Morse, a simple build like this can go a long way. For anyone else looking to build something similar we’d note that the DS1307 has a tendency to drift fairly quickly, and something like a DS3231 or even this similar Morse code clock which uses NTP would go a long way to keeping more accurate time.

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Nixie Display Module Is Addressable Via SPI

There are plenty of SPI interface screens on the market, but few of them have the charm of the good old Nixie tube. [Tony] decided to whip up a simple three-Nixie module that could be addressed via SPI. 

The stacked construction keeps things compact.

The module relies on a PIC16F15344 microcontroller to run the show, using its built-in SPI interface. It’s built with four stacked-up PCBs for ease of assembly and testing. It uses an internal buck converter to create the 170 volts required for the Nixie tubes from a 6 to 12 volt input. The high-voltage lines are routed towards the inside of the stack to minimize any nasty shocks when handling, though caution would still be advisable.

Driving the display is as simple as sending 16-bit words over the SPI interface, with the device operating in SPI client mode 1. If you’re looking for a simple way to have projects write output to a nice Nixie display, this module could be just what you’re looking for. Alternatively, if you can’t lay your hands on the tubes, there are other pretty solutions out there, too. Video after the break.

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Electronic Dice Is Introduction To Microcontroller Programming

By now most of us are familiar with the Arduino platform. It’s an inexpensive and fairly easy way into the world of microcontrollers. For plenty of projects, there’s no need to go beyond that unless you have a desire to learn more of the inner workings of microcontrollers in general. [Cristiano] was interested in expanding some of his knowledge, so he decided to build this electronic dice using a PIC microcontroller instead of the Arduino platform he was more familiar with.

As a result, this project is set up as a how-to for others looking to dive further into the world of microcontrollers that don’t have the same hand-holding setup as the Arduino. To take care of the need for a random number for the dice, the PIC’s random number generator is used but with the added randomness of a seed from an internal timer. The timer is started when a mercury tilt switch signals the device that it has been rolled over, and after some computation a single digit number is displayed on a seven-segment display.

While it might seem simple on the surface, the project comes with an in-depth guide on programming the PIC family of microcontrollers, and has a polish not normally seen on beginner projects, including the use of the mercury tilt switch which gives it a retro vibe. For some other tips on how to build projects like this, take a look at this guide on how to build power supplies for your projects as well.

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Sound Generation Board Makes The Tunes

[Mcjack123] has been getting into chiptunes lately and realized that his original interest started in 2018 when he used an Arduino to turn a TI-84 calculator into a sound machine. His latest iteration is a custom-designed soundboard and he takes us through the design and construction of it in a recent post.

The work models classic sound generators like the 2A03 or the Commodore 64 SID. You have a bunch of simple waveform generators along with filters and modulators to make various effects. These boards eventually gave way to FM synthesis devices like the Yamaha OPL2 and OPL3 chips. All of these cards accepted commands and generated audio on their own. More modern boards are more likely to simply convert digital data from the computer into audio.

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An image showing a water cooler PCB on the desk, with probes and jumper wires connected to it.

Taking Water Cooler UX Into Your Own Hands With Ghidra

Readers not aware of what Ghidra is might imagine some kind of aftermarket water cooler firmware or mainboard – a usual hacker practice with reflow ovens. What [Robbe Derks] did is no less impressive and inspiring:  A water cooler firmware mod that adds hands-free water dispensing, without requiring any hardware mods or writing an alternative firmware from scratch.

Having disassembled the cooler, [Robbe] found a PIC18F6527 on the mainboard, and surprisingly, it didn’t have firmware readback protection. Even lack of a PICkit didn’t stop him – he just used an Arduino to dump the firmware, with the dumper code shared for us to reuse, and the resulting dumps available in the same repository.

From there, he involved Ghidra to disassemble the code, while documenting the process in a way we can all learn from, and showing off the nifty tricks Ghidra has up its sleeves. Careful planning had to be done to decide which functions to hook and when, where to locate all the extra logic so that there’s no undesirable interference between it and the main firmware, and an extra step taken to decompile the freshly-patched binary to verify that it looks workable before actually flashing the cooler with it.

The end result is a water cooler that works exactly as it ought to have worked, perhaps, if the people defining its user interaction principles were allowed to make it complex enough. We could argue whether this should have been a stock function at all, but either way, it is nice to know that we the hackers still have some of the power to make our appliances friendly — even when they don’t come with an OS. Certainly, every single one of us can think of an appliance long overdue for a usability boost like this. What are your examples?

We’ve covered quite a few Ghidra-involving hacks, but it never feels like we’ve had enough. What about patching an air quality meter to use Fahrenheit? Or another highly educational write-up on cracking GBA games? Perhaps, liberating a Linux-powered 4G router to reconfigure it beyond vendor-defined boundaries? If you have your own goal in mind and are looking to start your firmware reverse-engineering journey, we can say with certainty that you can’t go wrong with our HackadayU course on Ghidra.

Three-Dimensional Design Yields Compact Seven-Segment Hex Displays

Computers, from the simplest to the most complex, aren’t very useful if they can’t provide feedback to a user. Whether that interface takes the form of a monitor, a speaker, or a simple LED, there’s almost always some kind of output. One of the most ubiquitous is the ever-present seven-segment display. They’re small, they’re easy to use, and, perhaps most important, they’re cheap.

While the displays themselves are relatively compact, they often require some sort of driver circuitry — something that translates a digit into voltage at the correct pins. These drivers can take up valuable space, especially on a breadboard, and can sometimes make using seven-segment displays cumbersome. Thankfully, [John Lonergan] has a great solution: driver boards that sit completely beneath the displays. His dual seven-segment hex display project was born out of necessity — he needed it for the breadboard CPU SPAM-1, which was getting a bit too bulky. Each module is two seven-segment displays atop a small PCB. Beneath the displays lives an 8-bit PIC microcontroller, which acts as a driver for both of the displays.

It’s so easy to restrict ourselves to thinking in two dimensions when working on electronic design — even designing multilayer PCBs often feels like working on several, distinct two-dimensional areas rather than one three-dimensional one. The concept of stacking components to save space, while fairly straightforward to implement, is a great example of the kind of problem-solving we love to see here at Hackaday. Of course, if you like the idea of 3D circuit design, you have to check out some of these incredible circuit sculptures we’ve featured in the past.

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Hacking A PIC To Redefine A Microphone’s Transmit Frequency

Software defined radio and widespread software-controlled PLL synthesis for RF has been a game changer. Things like the RTL-SDR can be any kind of radio you like on almost any frequency you like. But not every SDR or PLL system opens the configuration doors to you, the end user. That was the problem [vgnotepad] faced when trying to connect a Sennheiser wireless microphone to some receivers. They didn’t use the same frequencies, even though the transmitter was programmable. The solution to that is obvious — hack the transmitter!

The post is only part one of several parts and if you read to the end, you’ll learn a lot about what’s inside the device and how to crack it. Luckily, the device uses a PIC processor, so getting to the software wasn’t a big issue.

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