Author: Jenny List

3308 Articles

A Label Printer Gets A New Brain

September 1, 2025 by 9 Comments

The internals of a printer, whatever technology it may use, are invariably proprietary, with an abstracted more standard language being used to communicate with a host computer. Thus it’s surprisingly rare to see hacks on printers as printers, rather than printer hacks using the parts for some other purpose. This makes [Oelison]’s brain-swap of a Casio thermal label printer a welcome surprise, as it puts an ESP32 in the machine instead of whatever Casio gave it.

The value in the hack lies in the insight it gives into how a thermal printer works as much as it does in the ESP32 and the Casio, as it goes into some detail on the various signals involved. The strobe line for instance to enable the heater is a nuance we were unaware of. The resulting printer will lose its keyboard and display, but  make up for it in connectivity.

Despite what we said earlier this isn’t the first label printer hack we’ve seen. A previous one was Linux-based though.

Lightning Talks On Time, With This Device

August 31, 2025 by 3 Comments

Ask a Hackaday scribe who’s helped run the lightning talks at one of our events, and they’ll tell you that keeping the speakers on time is a challenge. Conversely if the staffer is trying to indicate to the speaker how much time they have left, it must be difficult from the podium to keep track while delivering your talk. Fortunately there’s [makeTVee] waiting in the wings with a solution, a cube whose faces each have a custom 5×7 LED matrix on them. The countdown is clear and unambiguous, and should provide no distractions.

The brains behind it all is a XIAO nRF52840 Sense board using the Zephyr RTOS, the LEDs are WS2812s on their own PCBs, and the party piece is only revealed at the end of the countdown. A tilt mechanism triggered by a servo releases a ball bearing down a track, where it hits a telephone bell and provides a very audible reminder to the speaker. The result saw action during the lightning talks at the Hackaday Europe event earlier in the year, but it’s taken a while for the write-up to make it online.

Continue reading “Lightning Talks On Time, With This Device” →

CAD, From Scratch: MakerCAD

August 29, 2025 by 29 Comments

It’s likely that many of you use some form of CAD package, but how many of you have decided you didn’t like the software on offer? [Marcus Wu] did, and instead of griping, he wrote his own CAD software. It’s called MakerCAD, it’s published under an MIT licence, and you can try it yourself.

It’s written in Go, and it’s superficially similar to OpenSCAD in that the interface is through code. The similarity is skin deep though, as it provides the user with constraint solving as described in the video below the break.

As it stands it’s by no means feature complete, but it is now at a point at which it can be evaluated. Simple models can be created and exported as STEP files, so it can be used as a real-world CAD tool.

Whether it will flourish is down to the path it takes and how its community guides it. But we’re pleased to see any new open source projects in this space, which remains overly dominated by proprietary packages. If you try it, write up your experiences, we’d love to see how this develops.

Continue reading “CAD, From Scratch: MakerCAD” →

Pi Port Protection PCB

August 25, 2025 by 16 Comments

We’re used to interfaces such as I2C and one-wire as easy ways to hook up sensors and other peripherals to microcontrollers. While they’re fine within the confines of a small project, they do have a few limitations. [Vinnie] ran straight into those limitations while using a Raspberry Pi with agricultural sensors. The interfaces needed to work over long cable runs, and to be protected from ESD due to lightning strikes. The solution? A custom Pi interface board packing differential drivers and protection circuits aplenty.

The I2C connection is isolated using an ISO1541 bus isolator from TI, feeding a PCA9615DP differential I2C bus driver from NXP. 1-wire is handled by a Dallas DS2482S 1-wire bus master and an ESD protection diode network. Even the 5-volt power supply is delivered through an isolated module.

Whether or not you need this Raspberry Pi board, this is still an interesting project for anyone working with these interfaces. If you’re interested, we’ve looked at differential I2C in the past.

A PLL For Perfect Pitch

August 24, 2025 by 5 Comments

When Hackaday runs a contest, we see all manner of clever projects. But inevitably there are some we don’t see, because their builders didn’t manage to get them finished in time. [Park Frazer]’s phase-locked loop is one of them. The circuit is an all-discrete PLL that derives a 440 Hz output from a 1 Hz input, and it arrived just too late for our 1 Hz contest.

If you aren’t familiar with a phase-locked loop, in this context you can think of them as a programmable frequency multiplier. A voltage-controlled oscillator is locked to an input frequency by comparing the two with a phase detector. Multiplication can be achieved by putting a frequency divider between the oscillator and the phase detector. It’s at the same time a complex and easy to understand circuit. In this case, when broken down into a set of multivibrators, it makes sense. The charge pump phase detector is a little different from the XOR gate we were expecting, but as he explains, it’s better.

If PLLs are a mystery, have a look at this video from a [Jeri Ellsworth] and [Bil Herd].

The 32 Bit 6502 You Never Had

August 24, 2025 by 43 Comments

In the beginning was the MOS6502, an 8-bit microprocessor that found its way into many famous machines. Some of you will know that a CMOS 6502 was created by the Western Design Center, and in turn, WDC produced the 65C816, a 16-bit version that was used in the Apple IIgs as well as the Super Nintendo. It was news to us that they had a 32-bit version in their sights, but after producing a datasheet, they never brought it to market. Last October, [Mike Kohn] produced a Verilog version of this W65C832 processor, so it can be experienced via an FPGA.

The description dives into the differences between the 32, 16, and 8-bit variants of the 6502, and we can see some of the same hurdles that must have faced designers of other chips in that era as they moved their architectures with the times while maintaining backwards compatibility. From our (admittedly basic) understanding it appears to retain that 6502 simplicity in the way that Intel architectures did not, so it’s tempting to imagine what future might have happened had this chip made it to market. We’re guessing that you would still be reading through an Intel or ARM, but perhaps we might have seen a different path taken by 1990s game consoles.

If you’d like to dive deeper into 6502 history, the chip recently turned 50.

Thanks [Liam Proven] for the tip.

Candle Oscillator Really Heats Things Up

August 23, 2025 by 11 Comments

As the timebase for a clock, almost anything with a periodic oscillation can be used. Traditionally, that meant a pendulum, but in our time, we’ve seen plenty of others. Perhaps none as unusual as [Tim]’s candle flicker clock, though.

Candles are known for their flickering, a property of the wick and the fuel supply that candle manufacturers have gone to great lengths to mitigate. If you bring several of them together, they will have a significant flicker, with a surprisingly consistent 9.9 Hz frequency. This is the timebase for the clock, with the capacitance of the flame being sensed by a wire connected to a CH32 microcontroller, and processed to produce the required timing.

We like this project, and consider it a shame that it’s not an entry in our One Hertz Challenge.  Oddly, though, it’s not the first candle-based oscillator we’ve seen; they can even be turned into active electronic devices.