Author: Jenny List

3073 Articles

Hackaday Podcast Episode 313: Capacitor Plague, Wireless Power, And Tiny Everything

March 21, 2025 by 3 Comments

We’re firmly in Europe this week on the Hackaday podcast, as Elliot Williams and Jenny List are freshly returned from Berlin and Hackaday Europe. A few days of mingling with the Hackaday community, going through mild panic over badges and SAOs, and enjoying the unique atmosphere of that city.

After discussing the weekend’s festivities we dive right into the hacks, touching on the coolest of thermal cameras, wildly inefficient but very entertaining wireless power transfer, and a restrospective on the capacitor plague from the early 2000s. Was it industrial espionage gone wrong, or something else? We also take a moment to consider spring PCB cnnectors, as used by both one of the Hackaday Europe SAOs, and a rather neat PCB resistance decade box, before looking at a tryly astounding PCB blinky that sets a new miniaturisation standard.

In our quick roundup the standouts are a 1970s British kit synthesiser and an emulated 6502 system written in shell script, and in the can’t-miss section we look at a new contender fro the smallest microcontroller, and the posibility that a century of waste coal ash may conceal a fortune in rare earth elements.

Follow the link below, to listen along!

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Three SPI Busses Are One Too Many On This Cheap Yellow Display

March 20, 2025 by 23 Comments

The Cheap Yellow Display may not be the fastest of ESP32 boards with its older model chip and 4 MB of memory, but its low price and useful array of on-board peripherals has made it something of a hit in our community. Getting the most out of the hardware still presents some pitfalls though, as [Mark Stevens] found out when using one for an environmental data logger. The problem was that display, touch sensor, and SD card had different SPI busses, of which the software would only recognise two. His solution involves a simple hardware mod, which may benefit many others doing similar work.

It’s simple enough, put the LCD and SD card on the same bus, retaining their individual chip select lines. There’s a track to be cut and a bit of wiring to be done, but nothing that should tax most readers too much. We’re pleased to see more work being done with this board, as it remains a promising platform, and any further advancements for it are a good thing. If you’re interested in giving it a go, then we’ve got some inspiration for you.

Pick Up A Pebble Again

March 19, 2025 by 38 Comments

A decade ago, smartwatches were an unexplored avenue full of exotic promise. There were bleeding-edge and eye-wateringly expensive platforms from the likes of Samsung or Apple, but for the more experimental among technophiles there was the Pebble. Based on a microcontroller and with a relatively low-resolution display, it was the subject of a successful crowdfunding campaign and became quite the thing to have. Now long gone, it has survived in open-source form, and now if you’re a Pebble die-hard you can even buy a new Pebble. We’re not sure about their choice of name though, we think calling something the “Core 2 Duo” might attract the attention of Intel’s lawyers.

The idea is broadly the same as the original, and remains compatible with software from back in the day. New are some extra sensors, longer battery life, and an nRF52840 BLE microcontroller running the show. It certainly captures the original well, however we’re left wondering whether a 2013 experience still cuts it in 2025 at that price. We suspect in that vein it would be the ideal compliment to your game controller when playing Grand Theft Auto V, another evergreen 2013 hit.

We look forward to seeing where this goes, and we reported on the OS becoming open source earlier this year. Perhaps someone might produce a piece of open source hardware to do the same job?

This M5Stack Game Is Surprisingly Addictive

March 19, 2025 by 4 Comments

For those of us lucky enough to have been at Hackaday Europe in Berlin, there was a feast of hacks at our disposal. Among them was [Vladimir Divic]’s gradients game, software for an M5Stack module which was definitely a lot of fun to play. The idea of the game is simple enough, a procedurally generated contour map is displayed on the screen, and the player must navigate a red ball around and collect as many green ones as possible. It’s navigated using the M5Stack’s accelerometer, which is what makes for the engaging gameplay. In particular it takes a moment to discover that the ball can be given momentum, making it something more than a simple case of ball-rolling.

Underneath the hood it’s an Arduino .ino  file for the M5Stack’s ESP32, and thus shouldn’t present a particular challenge to most readers. Meanwhile the M5Stack with its versatile range of peripherals has made it onto these pages several times over the years, not least as a LoRA gateway.

A 6502, In The Shell

March 17, 2025 by 8 Comments

Shell scripting is an often forgotten programming environment, relegated to simple automation tasks and little else. In fact, it’s possible to achieve much more complex tasks in the shell. As an example, here’s [calebccf] with an emulated 6502 system in a busybox ash shell script.

What’s in the emulator? A simple 6502 system with RAM, ROM, and an emulated serial port on STDIO. It comes with the wozmon Apple 1 monitor and BASIC, making for a very mid-1970s experience. There’s even a built-in monitor and debugger, which from our memories of debugging hand-assembled 8-bit code back in the day, should be extremely useful.

Although the default machine has a generous 32k of RAM and 16k ROM, you can easily adjust these limits by editing machine.sh. In addition, you can get a log of execution via a socket if you like. Don’t expect it to run too fast, and we did have to adjust the #! line to get it to run on our system (we pointed it to bash, but your results may vary).

What you use this for is up to you, but we’re sure you’ll all agree it’s an impressive feat in the shell. It’s not the first time we’ve seen some impressive feats there, though. Our Linux Fu column does a lot with the shell if you want further inspiration.

Probably The Simplest Sequencing Synth

March 15, 2025 by 31 Comments

With inexpensive microntrollers capable of the most impressive feats of sound synthesis, it’s not so often we see projects that return to an earlier style of electronic music project. The 1-bit synth from [Electroagenda] takes us firmly into that territory, employing that most trusty of circuits, a 555.

It’s a time-honored circuit, a 555 provides a note clock that drives a 4017 that functions as a sequencer. This switches in a set of voltage dividers, which in turn control another 555 oscillator that produces the notes. It’s a fun toy straight from the 1970s, right down to the protoboard and hookup wire construction. There’s a demo video with some lovely beeps below, and we think most of you should have what it takes to make your own.

If you’re seeking more inspiration, may we introduce you to our Logic Noise series?

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A Decade Resistance Box From PCBs

March 13, 2025 by 19 Comments

One of those useful things to have around on your bench is a decade resistance box, essentially a dial-a-resistance instrument. They used to be quite expensive in line with the cost of close-tolerance resistors, but the prices have come down and it’s within reach to build your own. Electronic design consultancy Dekimo have a nice design for one made from a series of PCBs which they normally give out at trade fairs, but now they’ve released the files for download.

It’s released as Gerbers and BOM with a pick-and-place file only, and there’s no licence so it’s free-as-in-beer [Editor’s note: the license has been updated to CC-BY-SA], but that should be enough if you fancy a go. Our Gerber viewer is playing up so we’re not entirely sure how reliable using PCBs as wafer switches will be long-term, but since the pictures are all ENIG boards we’d guess the gold plating will be much better than the HASL on all those cheap multimeters.

We like this as a conference giveaway, being used to badges it’s refreshing to see a passive take on a PCB artwork. Meanwhile this isn’t the first resistance box we’ve seen with unconventional switches.