2026-04-30 02:30:10
This week Jonathan chats with Andrei, Mahir, and Praneeth, live on location at Texas Instruments! The team at TI has been working hard to provide really good Open Source support for Sitara processors, including upstreaming support to the mainline Linux kernel. We talk about the CI pipeline for these devices, the challenges of doing Open Source at a big company, and more. Check it out!
Did you know you can watch the live recording of the show right on our YouTube Channel? Have someone you’d like us to interview? Let us know, or have the guest contact us! Take a look at the schedule here.
Direct Download in DRM-free MP3.
If you’d rather read along, here’s the transcript for this week’s episode.
Theme music: “Newer Wave” Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
2026-04-30 01:00:21
For the average rider, inner tubes have been one of the most enduring and unchanging parts of bicycle design over the decades. They’re made of rubber, they have a Schrader or Presta valve, and they generally do an okay job at cushioning the ride.
However, if you’re an above-average rider, or just obsessive about your gear, you might consider butyl rubber tubes rather old hat. Today, there are far fancier—and more expensive—options on the market if you’re looking to squeeze every drip of performance out of your bike.
Butyl rubber inner tubes have a lot of things going for them, which is why they’ve been the standard forever. Rubber holds air well, and is easy enough to repair in the event of a puncture. It’s also cheap. However, there are some ways in which the butyl inner tube holds a bicycle back. A thick rubber tube isn’t exactly light; even in a road bicycle application, a single tube can weigh 100 grams or more. They also add to the rolling resistance of a wheel and tire combination. In these regards, other materials have the potential to offer greater performance.
Latex is a material with many familiar uses, but it’s also recently become a popular alternative material for making inner tubes. It has the benefit of being very light, with a typical road bike latex tube saving 50 grams or more compared to the butyl rubber equivalent. The more flexible material also reduces rolling resistance by several watts at higher speeds, something which can make a real difference under competitive racing conditions. In a more qualitative sense, many riders also prefer the feel of riding on lighter latex tubes.
However, latex tubes also come with drawbacks. The ultra-thin, lightweight material can be susceptive to sudden failure from excessive heat, which can risk a crash in the worst cases. For this reason, the lightest latex tubes are often recommended for use on disc brake bikes only, due to the high temperatures that can be generated by rim brakes on a long descent. Latex tubes also lose air relatively quickly, and thus it’s recommended to pump up latex tubes to the required pressure ahead of every ride. They’re also difficult, but not impossible, to patch, and require some care to avoid damaging their thin walls during installation.
You might be familiar with thermoplastic polyurethane (TPU) for its use as a flexible 3D printing filament. As it turns out, it’s also a viable material for producing bicycle inner tubes. TPU tubes shave off weight and rolling resistance compared to butyl rubber, albeit not quite as much as the finest latex tubes out there. They do, however, hold air a lot better than latex, reducing the need to reset tyre pressure before each ride. Ride quality is also generally considered better than rolling on traditional butyl rubber tubes. TPU tubes also fold up incredibly small—a largely meaningless benefit in use, but really helpful if you’re trying to pack a spare or three to take on a ride.
Unfortunately, TPU tubes can be quite expensive to procure—often double the price of latex and three or four times that of a butyl rubber tube. The thinnest versions can similarly be at risk of heat failures when used with rim brakes, so it’s important to check before installation if your TPU tubes are rated for use with disc brakes only. Puncture repair can also be difficult, though there are some specialist patches on the market if you wish to attempt it.
It’s worth noting that there is another way to go, as well. It’s possible to buy wheel and tire setups that eliminate inner tubes entirely. These “tubeless” systems offer a major weight reduction, and tend to have lower rolling resistance than even the lightest, most flexible tube setups out there. They’re not really a development of tube technology, but moreso a divergence in wheel and tyre design. In any case, they are pricy, and can require some special equipment to install and maintain. To allow them to self-heal in the event of minor punctures, they’re also typically filled with sealant. In the event of more serious damage, it’s often still possible to install a tube to keep riding, but this is an incredibly messy process that will get sealant all over you.
If you’re a regular commuter cyclist, butyl rubber tubes will probably remain your go-to choice. They’re the cheapest to buy, the easiest to repair, and any benefits from lighter, more efficient tubes are largely wasted on a commute. However, if you’re an avid road cyclist looking for the best feel and efficiency, or especially if you’re getting serious about racing, then you really ought to consider leaving butyl behind for something better. Happy cycling!
2026-04-29 23:30:40
If you want to dabble in audio digital signal processing, you would probably think of grabbing a dedicated DSP chip. But thanks to [WeebLabs], you could just pick up a Pi Pico and use this full-featured DSP library.
The system supports plug-and-play USB audio interface that enumerates on Windows, Linux, macOS, and iOS. It can handle 16- or 24-bit inputs at up to 96 kHz. You can output up to four channels of 24-bit S/PDIF or I2S, or switch to an RP2350 to get eight channels. This lets you drive a DAC easily. There is also a direct output for a subwoofer that doesn’t require a DAC.
Each channel has a pre-amp, and a matrix mixer allows routing with different gains and phases for each input. An equalizer allows ten bands per channel. There are also modules to do volume leveling, loudness compensation, and headphone cross-feed.
The library uses both cores of the CPU and manages up to ten preset configurations. The Pico does get an overclock and uses a fixed-point representation. The Pico 2 (RP2350) doesn’t need overclocking and uses single-precision floating point.
Overall, this looks like a great base for any sort of soundcard-like project. We’ve seen DSP stunts on the Pico before. This might also make a nice base for other audio projects.
2026-04-29 22:00:16
There’s an old saying that the happiest days of a boat owner’s life are the day they buy the boat, and the day they sell it. For me, the happiest days of an Android tablet owner’s life are the day they buy a new one, and the day they buy a newer one. For some reason, I always buy tablets with great expectations, get them set up, and then promptly lose them in a pile on my desk, not to be seen again. Then a shiny new tablet gets my attention in a year or so, and the cycle repeats.
You might be thinking that I just buy cheap junk tablets. It is true that I have. But I have also bought new Galaxy and Asus tablets with the same result. Admittedly, I have owned several Surface Laptops and Pros, and I do use them. But I can’t remember the last time I have used one without the keyboard. They aren’t really tablets — they are just laptops that can also be heavy, awkward tablets.
I get the sense that iPad users get more use from their devices, but I’m not sure why. Maybe because Android tablets are really just blown-up phones. These days, my phone is big enough for most things. Sure, the tablet is bigger, but it isn’t that much bigger. In addition, my phone usually has a much better CPU, camera, and everything else. Not to mention it is constantly connected to the Internet, even if I’m not in range of a known WiFi router.
Read webpages? Phone. Play games? Phone. Deal with e-mail? Phone. The only advantage is if I put the tablet’s cheap Bluetooth keyboard on and use it like a laptop. But wait, I can just as well do that with the phone. Plus, voice typing for things like e-mails and messages is much better than it used to be.
Then there’s using it as a laptop replacement. When my laptop weighed a ton and got a few hours on a battery, that seemed like a good idea. But modern laptops don’t weigh that much, and they have pretty reasonable battery life, too. I always install some kind of Linux, like Termux and even Termux-X11, so I can use it as a lightweight Linux laptop. And I still don’t use it. (My setup is similar to the one in the video below, although you may have a few hiccups getting it all to work.)
Phone, tablet, or laptop, I’m still more likely to be found at my desk behind a big screen with a serious computer. Maybe it’s a generation gap, like clinging to a landline phone (I don’t) or a DVD player (another thing I don’t do). Maybe it is that most of the things I do on the computer benefit from large split screens and fast computing times.
Of course, there’s also the gadget factor. My desktop computer is huge and heavy, full of cards and water coolers, disk drives and fans. Some people trick out their cars. It is hard to expand most laptops, phones, and tablets, although I have had some success taking them apart for simple upgrades. They never seem to go back together quite right, though.
So then what do I actually want a tablet for? I don’t know. Which leads me to ask you: what are you using a tablet for? Do you really use it regularly? Or is it another gadget collecting dust? It doesn’t count if you repurpose them for some dedicated use: a second screen, a touchpad, or a 3D printer controller. I mean using them as a replacement for your normal computing platform. Let us know in the comments.
Maybe I’d be happier making my own tablet.
2026-04-29 19:00:50
Noctua wants to make life easier for fans of its…fans. To that end, the company has released a bevy of 3D models across its various product lines, all available to download for free.
If you’re not familiar with the company, Noctua specializes in high-quality cooling systems for the PC market. Its hope is that by freely providing 3D models of its components, it will aid aftermarket companies and DIYers that wish to integrate Noctua fans into their gear. In the company’s own words, these files are made available for “mechanical design, rendering, or animations.” They will let people check things like mountings and fitment without having to have the parts on hand, or to create demo visuals featuring the company’s products.
Don’t get too excited, though, because Noctua has already thought ahead. The company has specifically noted these parts aren’t intended for 3D printing, and critical components like fan blades have modified geometry so as to not compromise the companies IP. You could try and print these models, but they won’t perform like the real thing, and Noctua notes they shouldn’t be used for simulation purposes either. They’re intentionally not accurate to what the company actually sells in that regard.
That isn’t to say Noctua is totally against 3D printing. They have lots of parts available on Printables that they’d love you to try—everything from fan grilles to ducts to anti-vibration pads. Most are useful accessories—the kind of little bits of plastic that make using the products easier—that don’t threaten Noctua’s core product line in the marketplace.
If you’re whipping up a custom PC case and you want to kit it out with Noctua goodies, these models might help you refine your design. It’s funny how it’s such an opposite tactic to that taken by Honda, in terms of embracing the free exchange of 3D models on the open Internet. It’s a move that will surely be appreciated as a great convenience, and we’d love to see more companies follow this fine example.
Thanks to [irox] for the tip!
2026-04-29 16:00:41
Psygnosis’s 1995 game Wipeout is remembered for two things: being one of the greatest games of all time, and taking advantage of the then-new PlayStation’s capacity for 3D graphics. The ESP32-S3 might not be your first choice to replace Sony’s iconic console, but [Michael Biggins] a.k.a. [PhonicUK] is working on doing just that, with his own clone of Wipeout on the Expressif MCU.
It’s actually not that crazy when you think about it. The PlayStation had a 32-bit RISC processor, and the ESP32-S3 is a 32-bit RISC processor. The PlayStation’s was only good for about 30 Million Instructions Per Second (MIPS) but it had a graphics co-processor to help out with the polygons — the ESP32-S3 has two cores that can help each other, which combine to about 300 MIPS. In terms of RAM, the board in use has 8 MB of PSRAM, while the faster 512 kB on the chip is used, in effect, as video ram.
The demo is very impressive, especially considering he’s fit in three computer players. He’s also got it blasting out 60 frames per second, which is probably double what the original Wipeout ran on the PS1. Part of that is the two cores in action: he’s got them working together on the interlaced video output, one sending while the other finishes the second half of the frame. Each half of the video gets dedicated space in the internal memory. Using a 480×320 pixel display doesn’t hurt for speed, either. Sure, it’s paltry by modern standards, but the original Wipeout got by with even fewer pixels — and it didn’t run on a microcontroller. Granted it’s a beefy micro, but we really love how [Michael] is pushing its limits here.
Right now there’s just the Reddit thread and the demo video below. [Michael] is considering sharing the source code for his underlying 3D engine under an open license. We do hope he shares the code, as there are surely tricks in there some of us here could learn from. If it’s all old hat to you, perhaps you’d rather spend a weekend learning raytracing.
