2025 Component Abuse Challenge: Pushing A 555 To The Limit

November 7, 2025 by Jenny List 5 Comments

The humble 555 timer has its origins back in the early 1970s as the NE555, a bipolar integrated circuit. Over the years it has spawned a range of derivatives, including dual versions, and ones using CMOS technology. Have these enhancements improved the performance of the chip significantly? [MagicWolfi] has been pushing the envelope in an effort to see just how fast an astable 555 can be.

The Microchip MIC1555 may be the newest of the bunch, a 5-pin CMOS SOT-23 which has lost the frequency control and discharge pins of the original. It’s scarcely less versatile though, and it’s a fine candidate for an oscillator to push. We see it at a range of values for the capacitor and resistor in an astable configuration, each of which is tested across the supply voltage range. It’s rated as having a maximum frequency of 5 MHz, but with a zero Ohm resistor and only the parasitic capacitance of an open circuit, it reaches the giddy heights of 9.75 MHz. If we’re honest we find this surprising, but on reflection the chip would never be a first choice for super-fast operation.

We like it that someone’s managed to tie in the 555 to the contest, and given that it still has a few days to run at the time of writing, we’re hoping some of you might be inspired to enter one of your own.

An LED Projector As A Lighting Effect

November 7, 2025 by Jenny List 6 Comments

If you had an array of high power addressable LEDs, how would you project them onto a wall? Perhaps you’d use a Fresnel lens, or maybe an individual lens on the top of each. [Joo] faced this problem when making a lighting effect using just such an array, and the solution they came up with used both.

The problem facing a would-be LED array projector is that should the lens be too good, it will project the individual points of light from the LEDs themselves, when a more diffuse point is required. Thus the Fresnel required the aid of a separate array of lenses, resin printed in one in clear plastic. From this we get some useful tips on how to do this for best lens quality, and while the result is not quite optically perfect, it’s certainly good enough for the job in hand.

The linked Printables page comes with all you need to make the parts, and you too can have your own projected LED effect. Now we want one, too! Perhaps we really need our own Wrencher signal instead.

Countdown To Pi 1 Loss Of Support, Activated

November 6, 2025 by Jenny List 62 Comments

The older Raspberry Pi boards have had a long life, serving faithfully since 2012. Frankly, their continued support is a rarity these days — it’s truly incredible that an up-to-date OS image can still be downloaded for them in 2025. All good things must eventually come to an end though, and perhaps one of the first signs of that moment for the BCM2385 could be evident in Phoronix’s report on Debian dropping support for MIPS64EL & ARMEL architectures. Both are now long in the tooth and other than ARMEL in the Pi, rarely encountered now, so were it not for the little board from Cambridge this might hardly be news. But what does it mean for the older Pi?

It’s first important to remind readers that there’s no need to panic just yet, as the support is going not for the mainstream Debian releases, but the unstable and experimental ones. The mainstream Debian support period for the current releases presumably including the Debian-based Raspberry Pi OS extends until 2030, which tallies well with Raspberry Pi’s own end-of-life date for their earlier boards. But it’s a salutary reminder that that the clock’s ticking, should (like some of us) you be running an older Pi. You’ve got about five years.

A Pentium In Your Hand

November 5, 2025 by Jenny List 8 Comments

Handheld computers have become very much part of the hardware hacker scene, as the advent of single board computers long on processor power but short on power consumption has given us the tools we need to build them ourselves. Handheld retrocomputers face something of an uphill struggle though, as many of the components are over-sized, and use a lot of power. [Changliang Li] has taken on the task though, putting an industrial Pentium PC in a rather well-designed SLA printed case.

Aside from the motherboard there’s a VGA screen, a CompactFlash card attached to the IDE interface, and a Logitech trackball. As far as we can see the power comes from a USB-C PD board, and there’s a split mechanical keyboard on the top side. It runs Windows 98, and a selection of peak ’90s games are brought out to demonstrate.

We like this project for its beautiful case and effective use of parts, but we’re curious whether instead of the Pentium board it might have been worth finding a later industrial PC to give it a greater breadth of possibilities, there being few x86 SBCs. Either way it would have blown our minds back in ’98, and we can see it’s a ton of fun today. Take a look at the machine in the video below the break.

Continue reading “A Pentium In Your Hand” →

2025 Component Abuse Challenge: The Ever-Versatile Transistor As A Temperature Sensor

November 5, 2025 by Jenny List 20 Comments

One of the joys of writing up the entries for the 2025 Component Abuse Challenge has come in finding all the different alternative uses for the humble transistor. This building block of all modern electronics does a lot more than simply performing as a switch, for as [Aleksei Tertychnyi] tells us, it can also function as a temperature sensor.

How does this work? Simple enough, the base-emitter junction of a transistor can function as a diode, and like other diodes, it shows a roughly 0.2 volt per degree voltage shift with temperature (for a silicon transistor anyway). Taking a transistor and forward biasing the junction with a 33 K resistor, he can read the resulting voltage directly with an analogue to digital converter and derive a temperature reading.

The transistor features rarely as anything but a power device in the projects we bring you in 2025. Maybe you can find inspiration to experiment for yourself, and if you do, you still have a few days in which to make your own competition entry.

2025 Component Abuse Challenge: Weigh With A TL074

November 4, 2025 by Jenny List 19 Comments

The late and lamented [Bob Pease] was one of a select band of engineers, each of whose authority in the field of analogue integrated circuit design was at the peak of the art. So when he remarks on something in his books, it’s worth taking notice. It was just such an observation that caught the eye of [Trashtronic]; that the pressure on a precision op-amp from curing resin could be enough to change the device’s offset voltage. Could this property be used for something? The op-amp as a load cell was born!

The result is something of an op-amp torture device, resembling a small weighing machine with a couple of DIP-8 packages bearing the load. Surprisingly modest weights will change the offset voltage, though it was found that the value will drift over time.

This is clearly an experimental project and not a practical load cell, but it captures the essence of the 2025 Component Abuse Challenge of which it forms a part. Finding completely unexpected properties of components doesn’t always have to lead to useful results, and we’re glad someone had done this one just to find out whether or not it works. You still just about have time for an entry yourself if you fancy giving it a go.

Jenny’s Daily Drivers: ReactOS 0.4.15

November 4, 2025 by Jenny List 31 Comments

When picking operating systems for a closer look here in the Daily Drivers series, the aim has not been to merely pick the next well-known Linux distro off the pile, but to try out the interesting, esoteric or minority OS. The need remains to use it as a daily driver though, so each one we try has to have at least some chance of being a useful everyday environment in which a Hackaday piece could be written. With some of them such as the then-current BSD or Slackware versions we tried for interest’s sake a while back that’s not a surprising achievement, but for the minority operating systems it’s quite a thing. Today’s choice, ReactOS 0.4.15, is among the closest we’ve come so far to that ideal.

For The N’th Time In The Last 20 Years, I download A ReactOS ISO

A Windows-style ReactOS desktop with a web browser showing Hackaday — It’s fair to say there are still a few quirks, but it works.

ReactOS is an open-source clone of a Windows operating system from the early 2000s, having a lot on common with Windows XP. It started in the late 1990s and has slowly progressed ever since, making periodic releases that, bit-by-bit, have grown into a usable whole. I last looked at it for Hackaday with version 0.4.13 in 2020, so have five years made any difference? Time to download that ISO and give it a go.

Installing ReactOS has that bright blue and yellow screen feeling of a Windows install from around the millennium, but I found it to be surprisingly quick and pain free despite a few messages about unidentified hardware. The display driver it chose was a VESA one but since it supported all my monitor’s resolutions and colour depths that’s not the hardship it might once have been. Continue reading “Jenny’s Daily Drivers: ReactOS 0.4.15” →