electronic

11 Articles

2025 One Hertz Challenge: Using Industrial Relays To Make A Flasher

August 10, 2025 by 8 Comments

These days, if you want to flash some LEDs, you’d probably grab a microcontroller. Maybe you’d go a little more old-school, and grab a 555. However, [Jacob] is even more hardcore than that, as evidenced by this chunky electromechanical flasher build.

[Jacob] goes into great detail on his ancillary write-up, describing how the simple building blocks used by industrial control engineers can be used to make a flasher circuit that cycles once per second. Basically, two relays are paired with two 0.5-second delay timers. The two relays tag each other on and off on delay as their timers start and expire, with the lamp turned on and off in turn.

We’ve had lots of other great entries to our One Hertz Challenge, too — from clocks to not-clocks. There’s still time to get an entry in — the deadline for submission is Tuesday, August 19 at 9:00AM Pacific time. Good luck out there!

2025 Hackaday One Hertz Challenge

$800 Mountain Bike Seat Post Chopped In Two

August 29, 2022 by 16 Comments

For those unfamiliar with the sport of mountain biking, it’s a wild hobby that is rife with hacking. It started in the early 70s when the first dedicated mountain bikers were hacking road bikes together to ride on trails to varying levels of success, but only in the last decade or so have there been a lot of electronics appearing in various bike parts that we can all tinker with as well. This video discusses some of the downsides with a very expensive electronic seat post on a mountain bike, and attempts to solve its shortcomings by cutting it in half.

This build involves a dropper seat post, which is an adjustable seat for mountain biking that functions like an office chair. By pushing a button on the handlebars, the seat post can be rapidly adjusted up or down on-the-fly. Normally these seat posts use a cable to actuate, but this expensive version is wireless. The only problem is the battery will occasionally fly off when hitting big jumps, so [Berm Peak Express] decided to cut the existing proprietary battery system out and create a new housing for it. The new housing has a wired extension for the battery in its new location under the seat instead of behind it, and this gives it the clearance it arguably should have had from the manufacturer.

While not the most involved project of all time, it does take a certain mentality to take a hacksaw to a bike part that costs more than a large percentage of bicycles. It’s a niche product to be sure, but it also shows that some of the biggest annoyances with proprietary parts are not too difficult to overcome. And, it is interesting to see the ways that some people are hacking bikes outside of admittedly clever ebike conversions.

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555 Timer On Its Own In Electronic Dice

January 8, 2022 by 18 Comments

One of the most common clichés around here is that a piece of equipment chosen for a project is always too advanced. If a Raspberry Pi was used, someone will say they should have used an Arduino. If they use an Arduino, it should have been an ATtiny. And of course, if an ATtiny was used, there should have simply been a 555 timer. This time, however, [Tim] decided to actually show how this can be done by removing some of the integrated circuits from an electronic dice and relying entirely on the 555 timer for his build.

The electronic dice that [Tim] has on hand makes use of two main ICs: a NE555 and a CD4017 which is a decade counter/divider used for cycling through states. In order to bring the 555 to the forefront of this build, he scraps the CD4017 and adds an array of 555 timers. These are used to generate the clock signals necessary for this build but can also be arranged to form logic circuits. This comes at a great cost, however. The 555 chips take up an unnecessarily large area on the PCB (even though these are small surface-mount chips), consume an incredible amount of power, and are very slow. That’s fine for an electronic dice-rolling machine like this one, but that’s probably where [Tim] will leave this idea.

The 555 timer is a surprisingly versatile chip, and this project shows that there is some element of truth to the folks claiming that projects need naught but a few 555s. We’ve seen entire CPUs built using nothing but 555s, and even a classic project that uses a 555 timer to balance a robot.

He’s The Operator Of His Pocket Arduino

November 27, 2020 by 6 Comments

The band Kraftwerk hit the music scene with its unique electronic sound in the 70s in Germany, opening the door for the electronic music revolution of the following decade. If you’re not familiar with the band, they often had songs with a technology theme as well, and thanks to modern microcontroller technology it’s possible to replicate the Kraftwerk sound with microcontrollers as [Steven] aka [Marquis de Geek] demonstrates in his melodic build.

While the music is played on a Stylophone and a Korg synthesizer, it is fed through five separate Arduinos, four of which have various synths and looping samplers installed on them (and presumably represent each of the four members of Kraftwerk). Samplers like this allow pieces of music to be repeated continuously once recorded, which means that [Steven] can play entire songs on his own. The fifth Arduino functions as a controller, handling MIDI and pattern sequencing over I2C, and everything is finally channeled through a homemade mixer.

[Marquis] also dressed in Kraftwerk-appropriate attire for the video demonstration below, which really sells the tribute to the famous and groundbreaking band. While it’s a great build in its own right and is a great recreation of the Kraftwerk sound, we can think of one more way to really put this project over the top — a Kraftwerk-inspired LED tie.

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