Putting Cheap Motorcycle Tachometers To Work

January 18, 2025 by Tom Nardi 15 Comments

With so much data being thrown at our eyeballs these days, it’s worryingly easy for the actually important stuff to slip by occasionally. So when [Liam Jackson] wanted a way to visualize the number of test failures popping up in the continuous integration system at work, he went with a novel but effective solution — universal motorcycle tachometers.

It turns out these little gauges can be had for under $10 a piece from the usual overseas retailers, and are very easy to drive with a microcontroller. As [Liam] explains, all you need to do other than providing them with 12 volts, is feed them a PWM signal. Even though the gauges are designed for a 12 V system, they apparently don’t have any problem responding to the 5 V logic level from the Arduino’s pins.

As for the frequency he says that 1,000 RPM corresponds to 16.66 Hz, so you can just multiply up from there to show whatever number you wish. That said, [Liam] warns that the gauges draw several hundred milliamps once the needle gets into the two digit range, so keep that in mind. Conveniently, those number happen to be in red anyway…

For his particular application, [Liam] put three of the gauges together to create a very handsome dashboard. If you want to recreate his setup exactly he’s made the STLs available for the gauge cluster housing. Note the small OLED at the center, this offers a way to show a bit more context than the three analog gauges alone can express, especially if you’ve got an application where you might be switching between multiple data sources.

Over the years we’ve seen several projects that repurposed analog gauges of various types, often for showing computer performance, but they generally involved having to drive the galvanometers directly. That these tachometers can simply be fed a simple digital signal should make implementing them into your project much easier.

JTAG & SWD Debugging On The Pi Pico

January 18, 2025 by Tom Nardi 19 Comments

[Surya Chilukuri] writes in to share JTAGprobe — a fork of the official Raspberry Pi debugprobe firmware that lets you use the low-cost microcontroller development board for JTAG and SWD debugging just by flashing the provided firmware image.

We’ve seen similar projects in the past, but they’ve required some additional code running on the computer to bridge the gap between the Pico and your debugging software of choice. But [Surya] says this project works out of the box with common tools such as OpenOCD and pyOCD.

As we’ve cautioned previously, remember that the Pi Pico is only a 3.3 V device. JTAG and SWD don’t have set voltages, so in the wild you could run into logic levels from 1.2 V all the way to 5.5 V. While being able to use a bare Pico as a debugger is a neat trick, adding in a level shifter would be a wise precaution.

Looking to get even more use out of those Pi Picos you’ve got in the parts bin? How about using it to sniff USB?

Fighting To Keep Bluetooth Thermometers Hackable

January 16, 2025 by Tom Nardi 38 Comments

Back in 2020, we first brought you word of the Xiaomi LYWSD03MMC — a Bluetooth Low Energy (BLE) temperature and humidity sensor that could be had from the usual sources for just a few dollars each. Capable of being powered by a single CR2032 battery for up to a year, the devices looked extremely promising for DIY smart home projects. There was only one problem, you needed to use Xiaomi’s app to read the data off of the things.

Enter [Aaron Christophel], who created an open source firmware for these units that could easily be flashed using a web-based tool from a smartphone in BLE range and opened up all sorts of advanced features. The firmware started getting popular, and a community developed around it. Everyone was happy. So naturally, years later, Xiaomi wants to put a stop to it.

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Using The ESP8266 For Low-Cost Fault Injection

January 15, 2025 by Tom Nardi 10 Comments

As a general concept, fault injection is a technique that studies how a system reacts to unusual or unexpected external forces. The idea is that, if you can trigger a glitch at the precise moment, you might be able to use that to your advantage in disabling security features or otherwise gaining further access to the device in question. In the hardware world, this could be achieved by fiddling with the power going into the device, or subjecting it to extreme temperatures.

We’ve covered voltage glitching attacks on these pages in the past, but most of the tools used are fairly expensive if you’re not doing this kind of thing professionally. Luckily for us, [Aditya Patil] has developed a fault injection tool that can run on a standard ESP8266 development board. Obviously it’s not as capable as a bespoke device costing hundreds of dollars, but if you just want to experiment with the concept, it’s a fantastic way to wrap your head around it all.

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Procedurally Generated Terrain In OpenSCAD

January 14, 2025 by Tom Nardi 21 Comments

We’re big fans of OpenSCAD here at Hackaday — it’s free and open source software, runs on pretty much anything, and the idea of describing objects via code seems like a natural fit for producing functional parts. Rather than clicking and dragging elements on the screen, you can knock out a quick bracket or other simple component with just a few lines of code. But one of the things we don’t often get a chance to showcase is the incredible potential of generating 2D and 3D objects algorithmically.

In a recent Reddit post, [ardvarkmadman] dropped an extremely impressive snippet of OpenSCAD code that he calls TerrainGen. In fewer than fifteen lines of code, it’s able to create randomized “islands” which range from simple plateaus to craggy mountain ranges. After dropping the code in the OpenSCAD editor, you can just keep hitting F5 until you get a result that catches your eye. This seems like an excellent way to generate printable terrain elements for gaming purposes, but that’s just one possibility.

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Clever PCBs Straighten Out The Supercon SAO Badge

January 13, 2025 by Tom Nardi No comments

When we decided that Simple Add-Ons (SAOs) would be the focus of Supercon 2024, it was clear the badge would need to feature more than just one or two of the requisite connectors. We finally settled on six ports, but figuring out the geometry of getting all those ports on the badge in such a way that the SAOs wouldn’t hit each other was a bit tricky. In early concept drawings the badge was just a big rectangle with the ports along the top, but it was too ugly.

In the end we went with a somewhat organic design — an electronic “flower” with the radially arranged SAOs forming the petals, but this meant that that none of the SAOs were in the traditional vertical orientation. Luckily, [Adrian Studer] designed a couple of PCBs that not only resolve this issue, but add a seventh SAO port for good measure.

In the project repository you’ll find two PCB designs. The first, “SAO Up” is essentially a little arm that turns the SAO port 90 degrees. This doesn’t exactly get them vertical, in fact, whether or not the new orientation is actually an improvement for the top two SAOs is perhaps debatable. But it definitely helps on the lower SAOs, which are essentially upside down in their original configuration.

The real star of the show is “SAO Bridge”, a wavy board that connects across the two midline SAO ports on the Supercon badge and turns it into a set of three (nearly) horizontal connectors across the front. The center port is particularly helpful in that it gives you a place to put unusually wide SAOs.

As a reminder the Supercon SAO badge, and the winners of the 2024 SAO Contest, will be making the trip across the pond for Hackaday Europe in just a few months. That means you’ve still got plenty of time to have a few of these CERN-OHL-P licensed boards made up.

IFixit Releases Command Line Docs For FixHub Iron

January 11, 2025 by Tom Nardi 16 Comments

When we reviewed the iFixit FixHub back in September, one of the most interesting features of the portable soldering station was the command line interface that both the iron and the base station offered up once you connected to them via USB. While this feature wasn’t documented anywhere, it made a degree of a sense, as the devices used WebSerial to communicate with the browser. What was less clear at the time was whether or not the user was supposed to be fiddling with this interface, or if iFixit intended to lock it up in a future firmware update.

Thanks to a recent info dump on GitHub, it seems like we have our answer. In the repo, iFixit has provided documentation for each individual command on both the iron and base, including some background information and application notes for a few of the more esoteric functions. A handful of the commands are apparently disabled in the production version of the firmware, but there’s still plenty to poke around with.

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