2025-11-05 11:00:44
When you go on your favorite cheap online shopping platform and order a batch of 74LS logic ICs, what do you get? Most likely relabeled 74HC ICs, if the results of an AliExpress order by [More Fun Fixing It] on YouTube are anything to judge by. Despite the claims made by the somewhat suspect markings on the ICs, even the cheap component tester used immediately identified them as 74HC parts.
Why is this a problem, you might ask? Simply put, 74LS are Low-power Schottky chips using TTL logic levels, whereas 74HC are High-Speed CMOS, using CMOS logic levels. If these faked chips had used 74HCT, they would have been compatible with TTL logic levels, but with the TTL vs CMOS levels mismatch of 74HC, you are asking for trouble.
CMOS typically requires that high levels are at least 70% of Vcc, and low to be at most 30% of Vcc, whereas TTL high level is somewhere above 2.0V. 74HC also cannot drive its outputs as strongly as 74LC, which opens another can of potential issues. Meanwhile HCT can be substituted for LS, but with the same lower drive current, which may or may not be an issue.
Interestingly, when the AliExpress seller was contacted with these findings, a refund was issued practically immediately. This makes one wonder why exactly faked 74LS ICs are even being sold, when they’d most likely be stuffed into old home computers by presumably hardware enthusiasts with a modicum of skill and knowledge.
2025-11-05 08:00:46
Video games, movies, and modern militaries are all full of robotic gun turrets that allow for remotely-controlled carnage. [Paul Junkin] decided to build his own, albeit in a less-destructive paint-hurling fashion.
The turret sits upon a lazy susan bearing mounted atop a aluminium extrusion frame. A large gear is mounted to the bearing allowing the turret to pan when driven by a stepper motor. A pair of pillow block bearings hold a horizontal shaft which mounts the two paint markers, which again is controlled by another stepper motor to move in the tilt axis. An ESP32 microcontroller is responsible for running the show, panning and tilting the platform by commanding the large stepper motors. Firing the paintball markers is achieved with solenoids mounted to the triggers, which cycle fast enough to make the semi-auto markers fire in a way that almost feels like full-auto. Commanding the turret is via an Xbox One controller; communicating with the ESP32 over Bluetooth using the BluePad32 library.
It’s worth noting you shouldn’t shoot paintballs at unsuspecting individuals, since they can do extreme amounts of damage to those not wearing the proper protection. We’ve featured a great many other sentry guns over the years, too, like this impressive Portal-themed build. Video after the break.
2025-11-05 05:00:56
3D printing has taken off into the hands of almost anyone with a knack for wanting something quick and easy. No more messing around with machining or complex assembly. However, with the general hands-off nature of most 3D prints, what could be possible with a little more intervention during the printing process? [Ben] from Designed to Make represents this perfectly with an entire centrifugal pump printed as one.
This project may not entirely fit into the most strict sense of “print in place”; however, the entire pump is printed as one print file. The catch is the steps taken during printing, where a bearing is placed and a couple of filament changes are made to allow dissolvable supports to be printed. Once these supports are dissolved away, the body is coated with epoxy to prevent any leakage.
Testing done by [Ben] showed more than impressive numbers from the experimental device. Compared to previous designs made to test impeller features, the all in one pump could stand its own against in most categories.
If you want to check out the project yourself, check out the Hackaday project here. One of the greatest parts of the open source 3D printing world is the absolute freedom and ingenuity that comes out of it, and this project is no exception. For more innovations, check out this DIY full color 3D printing!
2025-11-05 03:30:10
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.
2025-11-05 02:00:27
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.
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.
Once installed, the feeling is completely of a Windows desktop from that era except for the little ReactOS logo on the Start menu. I chose the classic Windows 95 style theme as I never liked the blue of Windows XP. Everything sits where you remember it and has the familiar names, and if you used a Microsoft computer in those days you’re immediately at home. There’s even a web browser, but since it’s the WINE version of Internet Explorer and dates from the Ark, we’re guessing you’ll want to replace it.
There’s a package manager to download and run open-source software, something which naturally Windows never had. Back in 2020 I found this to be the Achilies’ heel of the OS, with very little able to install and run without crashing, so i was very pleased to note that this situation has changed. Much of the software is out of date due to needing Windows XP compatibility, but I found it to be much more usable and stable. There’s a choice of web browsers but the Firefox and Chromium versions are too old to be useful, but I found its K-Meleon version to be the most recent of the bunch. Adding GIMP to my installed list, I was ready to try this OS as my daily driver.
I am very pleased to report that using K-Meleon and GIMP on ReactOS 0.4.15, I could do my work as a Hackaday writer and editor. This piece was in part written using it, and Hackaday’s WordPress backend is just the same as in Firefox on my everyday Manjaro Linux machine. There however the good news ends, because I’m sorry to report that the experience was at times a little slow and painful. Perhaps that’s the non-up-to-date hardware I’d installed it on, but it’s evident that 2025 tasks are a little taxing for an OS with its roots in 2003. That said it remained a usable experience, and I could just about do my job were I marooned on a desert island with my creaking old laptop and ReactOS.
So ReactOS 0.4.15 is a palpable hit, an OS that can indeed be a Daily Driver. It’s been a long time, but at last ReactOS seems mature enough to use. I have to admit that I won’t be making the switch though, but who should be thinking about it? I think perhaps back in 2020 I got it right, in suggesting that as a pretty good facsimile of Windows XP it is best thought of as an OS for people who need XP bur for whom the venerable OS is now less convenient. It’s more than just a retrocomputing platform, instead it’s a supported alternative to the abandonware original for anyone with hardware or software from that era which still needs to run. Just like FreeDOS is now the go-to place for people who need DOS, so if they continue on this trajectory, should ReactOS become for those needing a classic Windows. Given the still-installed rump of software and computer controlled machinery which runs XP, that could I think become a really useful niche to occupy.
2025-11-05 00:30:33
The vast majority of model rockets go vaguely up and float vaguely downwards without a lot of control. However, [newaysfactory] built a few rockets that were altogether more precise in their flight, thanks to his efforts to master active roll control.
[newaysfactory] started this work a long time ago, well before Arduinos, ESP32s, and other highly capable microcontroller platforms were on the market. In an era when you had to very much roll your own gear from the ground up, he whipped up a rocket control system based around a Microchip PIC18F2553. He paired it with a L3G4200D gyro, an MPXH6115A barometer, and an MMA2202KEG accelerometer, chosen for its ability to provide useful readings under high G acceleration. He then explains how these sensor outputs were knitted together to keep a rocket flying straight and true under active control.
[newaysfactory] didn’t just master roll control for small rockets; he ended up leveraging this work into a real career working on fully-fledged autopilot systems. Sometimes your personal projects can take your career in interesting directions.
