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Friday, 17 January 2025

January 17, 2025

Android Head Unit Gets Volume Knob Upgrade

Touch screen head units are pretty much the norm these days. Many compromise with annoying on-screen volume controls or tiny buttons. If you find yourself with such a unit, you  might like to hack in a real volume knob. [Daniel Ross] shows us how to do just that.

The build uses an ATMega328 as the heart of the operation, though [Daniel] notes an Arduino Uno or Mini would have done just fine. It’s set up with a 74HC14 hex Schmitt trigger, and a CD4066 quad bilateral switch on a custom PCB. As for the volume knob itself, it’s not a real analog pot, instead it’s using a rotary encoder with a center push button. The way it works is that the Arduino reads the encoder, and figures out whether you’re trying to turn the volume up or down based on the direction you’re turning it. It then sends commands to the CD4066 to switch resistors in and out of circuit with lines going to the stereo to emulate the action of volume buttons on the steering wheel.

[Daniel’s] guide explains how everything works in greater detail, and how you can calibrate your head unit to accept these signals while preserving the function of your actual steering wheel volume buttons. Then you just have to find a neat way to integrate the knob into your existing dashboard.

We don’t see as many car stereo hacks in this era when infotainment systems rule all, but we’ve seen some great stuff from older vehicles over the years. Video after the break.



January 17, 2025

New Bambu Lab Firmware Update Adds Mandatory Authorization Control System

As per a recent Bambu Lab blog post, its FDM printers in the X1 series will soon receive a firmware update that adds mandatory authentication for certain operations, starting with the firmware update on January 23rd for the aforementioned FDM printers. These operations include performing firmware upgrades, initiating a print job (LAN or cloud), remote video access and adjusting parameters on the printer. Using the printer directly and starting prints from an SD card are not affected.

As reasoning for this new feature Bambu Lab points to recent exploits that gave strangers access to people’s printers, though cheekily linking to an article on an Anycubic printer exploit. While admittedly a concern, this mostly affects internet-exposed printers, such as those that are tied into a ‘cloud’ account. Even so, LAN-based printing also falls under this new mandatory authentication system, with Bambu Lab offering a new tool called Bambu Connect for those who insist on using non-Bambu Lab branded software like OrcaSlicer. This allows for exported G-code files to be sent to a (property authenticated) Bambu Lab printer.

For those who do not wish to use this feature, not upgrading the firmware is currently the only recourse. Although this firmware update is only for X1-series printers, Bambu Lab promised that it’ll arrive for their other printers too in due time. While Bambu Lab printer owners consider installing the alternative X1 Plus firmware, the peanut gallery can discuss the potential security issues (or lack thereof) of an open Fluidd or similar UI on their LAN-connected, Klipper-based FDM printers.

Thanks to [mip] for the tip.



Thursday, 16 January 2025

January 16, 2025

Neat Ring Clock Relies On Addressable LEDs

[WhiskeyTangoHotel] wanted to build an LED clock after seeing some great designs online. They elected to go after a ring clock design, based around the ever-popular WS2812B addressable LEDs.

The core of the build is the HELTEC WiFi 32 development board. It’s not one we’re intimately familiar with, but it’s based around the popular Expressif ESP32. Since it’s got WiFi, it’s able to simply dial up a network time server to always keep accurate time. It then drives a set of WS2812B LEDs set up in six rings. They display the current time with a layout akin to that of a typical analog clock.

What makes this build just a little more fun is the inclusion of Disco Mode. At the press of a button, the full set of LEDs flashes out some fun dancing patterns. The clock is also programmed to trigger the same display for sixty seconds at the top of each hour.

It’s a straightforward build—what might have been highly complicated to build two decades ago has been simplified with the magic of addressable LEDs. What’s also cool is that this clock was apparently inspired by another project shared on these very pages. If you’ve been spurred to build something cool yourself, don’t hesitate to notify the tipsline!



January 16, 2025

Building a Raycaster Within Bash

Wolfenstein 3D was a paradigm-shifting piece of software, using raycasting techniques to create a game with pseudo-3D graphics. Now, [izabera] has done something very similar, creating a raycasting display engine that runs entirely within bash.

The work was developed with an eye cast over an existing raycasting tutorial online. As you might imagine, implementing these graphical techniques in a text console proved difficult. The biggest problem [izabera] encountered was that bash is slow. It’s not supposed to display full frames of moving content at 25+ fps. It’s supposed to display text. Making it display graphics by using tons of colorful characters is really pushing the limits. Bash also doesn’t have any ability to work with floating points, so all the calculations are done with massive integers. Other problems involved the limited ways to read the keyboard in bash, and keeping track of the display as a whole.

It’s neat reading about how this was pulled off—specifically because it was hard. It might not be the kind of project you’d ever implement for serious work, but there are learnings to be had here that you won’t get anywhere else. Code is on Github, while there’s a visual storytelling of how it came together on imgur.

We’ve seen similar work before—with magical 3D graphics generated in Microsoft Excel. Will wonders never cease? We hope not, because we always like to see new ones on the tipsline. Keep us busy!



January 16, 2025

Repairing a Samsung 24″ LCD Monitor With Funky Color Issues

The old cable in place on the Samsung monitor. (Credit: MisterHW)
The old cable in place on the Samsung monitor. (Credit: MisterHW)

Dumpster diving is one of those experiences that can net you some pretty cool gear for a reasonable price. Case in point the 24″ Samsung S24E650XW LCD monitor that [MisterHW] saved from being trashed. Apparently in very good condition with no visible external damage, the unit even powered up without issues. It seemed like a golden find until he got onto the Windows desktop and began to notice quaint red shimmering in darker areas and other issues that made it clear why the monitor had been tossed. Of course, the second best part about dumpster diving is seeing whether you can repair such issues.

Prior to disassembly it had been noted that percussive maintenance and bending of the frame changed the symptoms, suggesting that something was a bit loose inside. After taking the back cover and shielded enclosure off, a quick visual inspection of the boards and cables quickly revealed the likely suspect: broken traces on one of the cables.

Apparently somewhere during the assembly step in the factory the cable had been pushed against the PCB’s edge, causing the initial damage. Based on the listed assembly date the monitor had only been in use for a few years before it was tossed, so likely the symptoms would have begun and worsened as one after another of the traces gradually cracked and broke due to vibrations, thermal expansion, etc.

This issue made fixing the monitor very simple, however, assuming a suitable replacement cable could be found. The broken cable is a 30P 1.0 pitch PFC, with EBay throwing up a cable with similar specs for a Thomson brand TV. One purchase and anxious wait later, the replacement cable was installed as in the featured image alongside the old cable. Perhaps unsurprisingly it restored the monitor to full working order, demonstrating once again that dumpster diving is totally worth it.



January 16, 2025

Building a 3D-Printed Strandbeest

The Strandbeest is a walking machine, a creation of the celebrated artist Theo Jansen. They can look intimidating in their complexity, but it’s quite possible to build your own. In fact, if you’ve got a 3D-printer, it can be remarkably straightforward, as [Maker 101] demonstrates.

The build relies on an Arduino Uno as the brains. It’s equipped with an L293D motor driver shield to run two DC gear motors which drive the walking assemblies. Power is courtesy of a 3-cell lithium-polymer battery. The chassis, legs, and joints are all 3D-printed, and rather attractively in complimentary colors, we might add.

Controlling this little Strandbeest is simple. [Maker 101] gave the Arduino an infrared sensor which can pick up signals from a simple IR remote control. It can be driven backwards and forwards or turned left and right. What’s more, it looks particularly elegant as it walks—a hallmark of a good Strandbeest design.

Design files are available online for the curious. We love a good Strandbeest build, and some can even be useful, too! Video after the break.



Wednesday, 15 January 2025

January 15, 2025

All The Attacks on the RP2350

Raspberry Pi’s new microcontroller, the RP2350, has a small section of memory that is meant for storing secrets. It’s protected by anti-glitching and other countermeasures, and the Raspberries wanted to test it. So this summer, they gave them out, pre-programmed with a secret string, as part of the badge for DEFCON attendees. The results of the cracking efforts are in, and it’s fair to say that the hackers have won.

First place went to [Aedan Cullen], who also gave a great talk about how he did it at 38C3. One of the coolest features of the RP2350, from a hacker perspective, is that it has dual ARM and dual RISC-V cores onboard, and they can be swapped out by multiplexers. The security module has a critical register that has disable bits for both of these processors, but it turns out that the ARM disable bits have priority. When [Aedan] glitched the security module just right, it disabled the ARM cores but left the RISC-V cores running in the secure context, with full debug(!), and the game was over. As of yet, there is no mitigation for this one, because it’s baked into the secure boot module’s silicon.

[Marius Muench] managed to pre-load malicious code into RAM and glitch a reboot-out-of-secure-mode on the USB module. This one is possibly fixable by checking other reboot flags. [Kévin Courdesses] has a sweet laser fault-injection rig that’s based on the 3D-printable OpenFlexure Delta Stage, which we’ve seen used for microscopy purposes, but here he’s bypassing the anti-glitching circuitry by exposing the die and hitting it hard with photons.

Finally, [Andrew Zonenberg] and a team from IOActive went at the RP2350 with a focused ion beam and just read the memory, or at least the pairwise-OR of neighboring bits. Pulling this attack off isn’t cheap, and it’s a more general property of all anti-fuse memory cells that they can be read out this way. Chalk this up as a mostly-win for the offense in this case.

If you want to read up on voltage glitching attacks yourself, and we promise we won’t judge, [Matthew Alt] has a great writeup on the topic. And ironically enough, one of his tools of choice is [Colin O’Flynn]’s RP2040-based Chip Shouter EMP glitcher, which he showed us how to make and use in this 2021 Remoticon talk.