915 MHz Forecast: Rolling Your Own Offline Weather Station

December 19, 2025 by Matt Varian 9 Comments

There are a lot of options for local weather stations; most of them, however, are sensors tied to a base station, often requiring an internet connection to access all features. [Vinnie] over at vinthewrench has published his exploration into an off-grid weather station revolving around a Raspberry Pi and an RTL-SDR for communications.

The weather station has several aspects to it. The main sensor package [Vinnie] settled on was the Ecowitt WS90, capable of measuring wind speed, wind direction, temperature, humidity, light, UVI, and rain amount. The WS90 communicates at 915 MHz, which can be read using the rtl_433 project. The WS90 is also available for purchase as a standalone sensor, allowing [Vinnie] to implement his own base station.

For the base station, [Vinnie] uses a weatherproof enclosure that houses a 12V battery with charger to act as a local UPS. This powers the brains of the operation: a Raspberry Pi. Hooked to the Pi is an RTL-SDR with a 915 MHz antenna. The Pi receives an update from the WS90 roughly every 5 seconds, which it can decode using the rtl_433 library. The Pi then turns that packet into structured JSON.

The JSON is fed into a weather model backend that handles keeping track of trends in the sensor data, as well as the health of the sensor station. The backend has an API that allows for a dashboard weather site for [Vinnie], no internet required.

Thanks, [Vinnie], for sending in your off-grid weather station project. Check out his site to read more about his process, and head over to the GitHub page to check out the technical details of his implementation. This is a great addition to some of the other DIY weather stations we’ve featured here.

Two four-cylinder engines mechanically linked and exhausting into a trombone.

Franken-engine Plays Its Own Swan Song At 15k RPM

December 3, 2025 by Tyler August 16 Comments

Back during WWII, Chrysler bodged five inline-6 engines together to create the powerful A57 multibank tank engine. [Maisteer] has some high-revving inline-4 motorcycle engines he’s trying to put together too, but unlike 1940s Chrysler, he also has a trombone… and a lot more RPMs to deal with.

The Chrysler flatheads were revving at a few thousand RPM– their redline was almost certainly in the three-thousand range. [Maisteer] is working at 15,000 RPM, which is where the real challenge of this build lies: the trombone in the image is just for fun. He wanted to use a heavy chain to link the crankshafts, but at that rotational speed, a heavy chain becomes really heavy— or at least, it feels a force many times its weight due to centrifugal force. The lietmotief of this video is a quote by an automotive engineer to the effect that chains don’t work over 10,000 RPM.

That leads to a few problems for the intrepid “not an engineer” that take most of the video to deal with and ultimately doom the engine linkage– for now. Not before he gets an iconic 8-cylinder sound out (plus some fire) out of a trombone, though. Of particular note is the maker-type workflow Hackaday readers will appreciate: he 3D scans the engines, CADs up parts he needs and sends away to have them CNC’d and SLS printed.

Hacking motorcycle engines into cars is nothing new. Hacking them together into franken-engines is something we see less often.

Thanks to [Keith Olson] for the tip! Remember, if you want to toot your own horn– or toot about someone else’s project, for that matter–the tips line is always open.

Continue reading “Franken-engine Plays Its Own Swan Song At 15k RPM” →

Fixing A Milltronics ML15 CNC Lathe Despite The Manufacturer’s Best Efforts

November 20, 2025 by Maya Posch 10 Comments

When you’re like [Wes] from Watch Wes Work fame, you don’t have a CNC machine hoarding issue, you just have a healthy interest in going down CNC machine repair rabbit holes. Such too was the case with a recently acquired 2001 Milltronics ML15 lathe, that at first glance appeared to be in pristine condition. Yet despite – or because of – living a cushy life at a college’s workshop, it had a number of serious issues, with a busted Z-axis drive board being the first to be tackled.

The Glentek servo board that caused so much grief. (Credit: Watch Wes Work, YouTube)

The identical servo control board next to it worked fine, so it had to be an issue on the board itself. A quick test showed that the H-bridge IGBTs had suffered the typical fate that IGBTs suffer, violently taking out another IC along with them. Enjoyably, this board by one Glentek Inc. did the rebranding thing of components like said IGBTs, which made tracking down suitable replacements an utter pain that was eased only by the desperate communications on forums which provided some clues. Of course, desoldering and testing one of the good IGBTs on the second board showed the exact type of IGBT to get.

After replacing said IGBTs, as well as an optocoupler and other bits and pieces, the servo board was good as new. Next, the CNC lathe also had a busted optical encoder, an unusable tool post and a number of other smaller and larger issues that required addressing. Along the way the term ‘pin-to-pin compatible’ for a replacement driver IC was also found to mean that you still have to read the full datasheet.

Of the whole ordeal, the Glentek servo board definitely caused the most trouble, with the manufacturer providing incomplete schematics, rebranding parts to make generic replacements very hard to find and overall just going for a design that’s interesting but hard to diagnose and fix. To help out anyone else who got cursed with a Glentek servo board like this, [Wes] has made the board files and related info available in a GitHub repository.

Continue reading “Fixing A Milltronics ML15 CNC Lathe Despite The Manufacturer’s Best Efforts” →

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” →

The Great ADS1115 Pricing And Sourcing Mystery

October 24, 2025 by Maya Posch 6 Comments

The AdaFruit ADS1115 board hooked up for testing. (Credit: James Bowman)

Following up on the recent test of a set of purported ADS1115 ADCs sourced from Amazon [James Bowman] didn’t just test a genuine Ti part, but also dug into some of the questions that came up after the first article. As expected, the AdaFruit board featuring a presumed genuine Ti ADS1115 part performed very well, even performing significantly better on the tested parameters than the datasheet guarantees.

Thus we can confirm that when you get the genuine Ti part, you can expect very good and reliable performance for your ADC purposes. Which leaves the unaddressed questions about what these cheapo Amazon-sourced ADS1115 ICs are, and how it can be that LCSC has what should be the same parts for so much cheaper than US distributors?

As far as LCSC pricing is concerned, these are likely to be genuine parts, but also the subject of what is known as price discrimination. This involves pricing the same product differently depending on the targeted market segment, with e.g. Digikey customers assumed to be okay with paying more to get the brand name assurance and other assumed perks. Continue reading “The Great ADS1115 Pricing And Sourcing Mystery” →

How Bad Can A Cheap Knockoff ADS1115 ADC Be?

October 15, 2025 by Maya Posch 29 Comments

Although the saying of caveat emptor rings loudly in the mind of any purveyor of electronic components, the lure of Very Cheap Stuff is almost impossible to resist. Sure, that $0.60 Ti ADS1115 ADC on LCSC feels like it almost has to be a knock-off since the same part on Digikey is $4 a pop, and that’s when you buy a pack of 1,000. Yet what if it’s a really good knockoff that provides similar performance for a fraction of the price, such as with those cheap ADC boards you can get from Amazon? Cue [James Bowman] letting curiosity getting the better of him and ordering a stash of four boards presumably equipped with at least some kind of cheapo knockoff part, mostly on account of getting all boards for a mere $2.97.

The goal was of course to subject these four purported ADS1115s to some testing and comparison with the listed performance in the Ti datasheet. Telling was that each of the ADCs on the boards showed different characteristics, noticeably with the Data Rate. This is supposed to be ±10% of the nominal, so 7.2 – 8.8 times per second in 8 samples per second mode, but three boards lagged at 6.5 – 7 SPS and the fourth did an astounding 300 SPS, which would give you pretty noisy results.

Using a calibrated 2.5 voltage source the accuracy of the measurements were also validated, which showed them to be too low by 12 mV. The good news was that a linear correction on the MCU can correct for this, but it shows that despite these parts being ADS1115 compatible and having features like the PGA working, you’re definitely getting dinged on performance and accuracy.

[James] said that he’s going to run the same tests on an ADS1115 board obtained from Adafruit, which likely will have the genuine part. We would also love to see someone test the $0.60 version from LCSC to see whether they can match the datasheet. Either way, if you are eyeing this ADC for your own projects, it pays to consider whether the compromises and potential broken-ness of the knockoffs are worth it over coughing up a bit more cash. As they say, caveat emptor.

CERN’s Large Hadron Collider Runs On A Bendix G-15 In 2025

August 25, 2025 by Adam Fabio 18 Comments

The Bendix G-15 refurbished by [David at Usagi Electric] is well known as the oldest fully operational digital computer in North America. The question [David] gets most is “what can you do with it?”. Well, as a general-purpose computer, it can do just about anything. He set out to prove it. Can a 1950s-era vacuum tube computer handle modern physics problems? This video was several years in the making, was a journey from [David’s] home base in Texas all the way to CERN’s Large Hadron Collider (LHC) in Switzerland.

The G-15 can run several “high-level” programming languages, including Algol. The most popular, though, was Intercom. Intercom is an interactive programming language – you can type your program in right at the typewriter. It’s much closer to working with a basic interpreter than, say, a batch-processed IBM 1401 with punched cards. We’re still talking about the 1950s, though, so the language mechanics are quite a bit different from what we’re used to today.

To start with, [Usagi’s] the G-15 is a numeric machine. It can’t even handle the full alphabet. What’s more, all numbers on the G-15 are stored as floating-point values. Commands are sent via operation codes. For example, ADD is operation 43. You have to wrangle an index register and an address as well. Intercom feels a bit like a cross between assembler and tokenized BASIC. Continue reading “CERN’s Large Hadron Collider Runs On A Bendix G-15 In 2025” →