This week, Jonathan Bennett, Randal Schwartz, and Aaron Newcomb chat about Linux, the challenges with using system modules like the Raspberry Pi, challenges with funding development, and more!

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 contact the guest and have them 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.

Last Thursday we were at Electronica, which is billed as the world’s largest electronics trade show, and it probably is! It fills up twenty airplane-hangar-sized halls in Munich, and only takes place every two years.

And what did we see on the wall in the Raspberry Pi department? One of the relatively new AI-enabled cameras running a real-time pose estimation demo, powered by nothing less than a brand-new Raspberry Pi Compute Module 5. And it seemed happy to be running without a heatsink, but we don’t know how much load it was put under – most of the AI processing is done in the camera module.

We haven’t heard anything about the CM5 yet from the Raspberry folks, but we can’t imagine there’s all that much to say except that they’re getting ready to start production soon. If you look really carefully, this CM5 seems to have mouse bites on it that haven’t been ground off, so we’re speculating that this is still a pre-production unit, but feel free to generate wild rumors in the comment section.

The test board looks very similar to the RP4 CM demo board, so we imagine that the footprint hasn’t changed. (Edit: Oh wait, check out the M2 slot on the left-hand side!)

The CM4 was a real change for the compute module series, coming with a brand-new pinout that enabled them to break out more PCIe lanes. Despite the special connectors, it wasn’t all that hard to work with if you’re dedicated. So if you need more computing power in that smaller form factor, we’re guessing that you won’t have to wait all that much longer!

Thanks [kuro] for the tip, and for walking around Electronica with me.

As impractical as most overclocking of computers is these days, there is still a lot of fun to be had along the way. Case in point being [Pieter-Jan Plaisier]’s recent liquid nitrogen-aided overclocking of an unsuspecting Raspberry Pi 5 and its BCM2712 SoC. Previous OCing attempts with air cooling by [Pieter] had left things off at a paltry 3 GHz from the default 2.4 GHz, with the power management IC (PMIC) circuitry on the SBC turning out to be the main limiting factor.

The main change here was thus to go for liquid nitrogen (LN₂) cooling, with a small chipset LN₂ pot to fit on the SBC. Another improvement was the application of a NUMA (non-uniform memory addressing) patch to force the BCM2712’s memory controller to utilize better RAM chip parallelism.

With these changes, the OC could now hit 3.6 GHz, but at 3.7 GHz, the system would always crash. It was time to further investigate the PMIC issues.

The PMIC imposes voltage configuration limitations and turns the system off at high power consumption levels. A solution there was to replace said circuitry with an ElmorLabs AMPLE-X1 power supply and definitively void the SBC’s warranty. This involves removing inductors and removing solder mask to attach the external power wires. Yet even with these changes, the SoC frequency had trouble scaling, which is why an external clock board was used to replace the 54 MHz oscillator on the PCB. Unfortunately, this also failed to improve the final overclock.

We covered the ease of OCing to 3 GHz previously, and no doubt some of us are wondering whether the new SoC stepping may OC better. Regardless, if you want to get a faster small system without jumping through all those hoops, there are definitely better (and cheaper) options. But you do miss out on the fun of refilling the LN₂ pot every couple of minutes.

Thanks to [Stephen Walters] for the tip.

This week, Jonathan Bennett and David Ruggles chat with Frank Delporte about Pi4J, the friendly Java libraries for the Raspberry Pi, that expose GPIO, SPI, I2C and other IO interfaces. Why would anyone want to use Java for the Pi? And what’s changed since the project started? Listen to find out!

• https://www.pi4j.com/
• https://webtechie.be/

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 contact the guest and have them 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.

At this point in the tech dystopia cycle, it’s no surprise that the initial purchase price of a piece of technology is likely not the last payment you’ll make. Almost everything these days needs an ongoing subscription to do whatever you paid for it to do in the first place. It’s ridiculous, especially when all you want to do is charge your electric motorcycle with electricity you already pay for; why in the world would you need a subscription for that?

That was [Maarten]’s question when he picked up a used EVBox wall mount charger, which refused to charge his bike without signing up for a subscription. True, the subscription gave access to all kinds of gee-whiz features, none of which were necessary for the job of topping off the bike’s battery. A teardown revealed a well-built device with separate modules for mains supply and battery charging, plus a communications module with a cellular modem, obviously the bit that’s phoning home and keeping the charger from working without the subscription.

After some time going down dead ends and a futile search for documentation, [Maarten] decided to snoop into the conversation between the charger boards and the comms board, reasonably assuming that if he knew what they were talking about, he’d be able to mimic the commands that make the charger go. He managed to do exactly that, reverse engineering enough of the protocol to do a simple replay attack using a Raspberry Pi. That let him use the charger. Problem solved, right?

Not so fast — this is a “Fail of the Week,” after all. This is where [Maarten] should have called it a day, but he decided to keep poking enough to snatch defeat from the jaws of victory. He discovered that the charging module’s firmware was only doing limited validation of messages coming from the comms module, and since he’d only found fourteen of the commands in the protocol, he thought he’d take advantage of the firmware’s openness to explore all 256 possible commands. Scanning through all the commands proved fatal to the charger, though, bricking the poor thing right after he’d figured everything out. Ouch!

To his credit, [Maarten] was only trying to be complete in his exploration of the protocol, and his intention to make it easier for the next hacker is laudable in the extreme. That he took it a byte too far is unfortunate, but such is the price we sometimes pay for progress. Everything he did is thoroughly documented, so if you’ve got one of these chargers you’ve got all the tools needed to make it a standalone. Just make sure you know when to stop.

From the 60s to perhaps the mid-00s, the path to musical stardom was essentially straight with very few forks. As a teenager you’d round up a drummer and a few guitar players and start jamming out of a garage, hoping to build to bigger and bigger venues. Few people made it for plenty of reasons, not least of which was because putting together a band like this is expensive. It wasn’t until capable electronic devices became mainstream and accepted in popular culture in the last decade or two that a few different paths for success finally opened up, and this groovebox shows just how much music can be created this way with a few straightforward electronic tools.

The groovebox is based on a Raspberry Pi Pico 2 and includes enough storage for 16 tracks with a sequencer for each track, along with a set of 16 scenes. Audio plays through PCM5102A DAC module, with a 160×128 TFT display and a touch-sensitive pad for user inputs. It’s not just a device for looping stored audio, though. There’s also a drum machine built in which can record and loop beats with varying sounds and pitches, as well as a sample slicer and a pattern generator and also as the ability to copy and paste clips.

There are a few limitations to using a device this small though. Because of memory size it outputs a 22 kHz mono signal, and its on-board storage is not particularly large either, but it does have an SD card slot for expansion. But it’s hard to beat the bang-for-the-buck qualities of a device like this, regardless, not to mention the portability. Especially when compared with the cost of multiple guitars, a drum set and a bunch of other analog equipment, it’s easy to see how musicians wielding these instruments have risen in popularity recently. This 12-button MIDI instrument could expand one’s digital musical capabilities even further.

Your phone or laptop will give you access to the vast majority of news in the world, in languages you can read and a few hundred you can’t. Maybe you only like one news source, though, and that news source happens to be Canadian Broadcasting Corporation (CBC). If that’s the case, you might like to give this project a look from [Ron Grimes].

[Ron] built a device that does one thing and one thing only: it displays news stories from CBC. It’s built around a Raspberry Pi 2, and the project began when he wanted to interface a keypad just to see if he could. With that done, the next challenge was to integrate a 16×2 character LCD display of the HD44780 persuasion. With those two tasks completed, the question was simple — what to display? He figured tuning into the CBC news feed would be useful, and the Chocolate Box News Reader was born.

The device displays 29 news feeds in total, including the main top stories, world news, and Canadian regional news. It stores 15 news items per feed and will hang on to those stories even if the Internet drops. The reader will display the whole stash of stored news in around 90 minutes or so, and each stored item comes with more information if something strike’s [Ron’s] curiosity or interest. Files are on GitHub for the curious.

It’s a neat build, and we can imagine it being a smart item to have kicking around the house. It was also a great way for [Ron] to build on his familiarity with the Raspberry Pi, too. Meanwhile, if you’ve got your own nifty Pi-based projects—or others!—don’t hesitate to drop us a line!

With the latest release of Raspberry Pi OS (formerly Raspbian) the end of the X Window System has become reality, completing a years-long transition period. Although this change between display servers is not something which should be readily apparent to the casual user, the change from the client-server-based X11 protocol to the monolithic Wayland protocol has a number of implications. A major change is that with the display server and window manager no longer being separate units, features such as network transparency (e.g. remote X-sessions) are no longer a native feature, but have to be implemented separately by e.g. the Wayland compositor.

For Raspberry Pi the transition to Wayland was based on the perceived efficiency and security benefits of the monolithic architecture, with the 2021 release of Raspbian (based on Debian Bullseye) testing the waters using the hybrid X11 window manager/Wayland compositor Mutter. This allowed for switching between X11 and Wayland without committing. In 2023 Mutter was replaced with the Wayfire compositor with Wayland becoming the default on Raspberry Pi 4 and 5 platforms. Along the way it was found that the Wayfire project wasn’t developing in a way that would benefit Raspberry Pi OS, which led to what should now be the final Wayland compositor in the form of Labwc.

One advantage of Labwc is that it is more lightweight than Wayfire and Raspberry Pi has judged that this means that it should be the default across all Raspberry Pi systems. Compatibility with X11-based software is maintained with the XWayland library, so that users should ideally not notice any difference after switching to Labwc even on lower-end boards. Unless you’re one one of those people who use features such as (remote) X-sessions, nothing should feel markedly different.

In addition to this big change, the new Raspberry Pi OS release also improves touch screen support with the integrated Squeekboard virtual keyboard popping up when a touch screen is detected. Finally, the remote access Raspberry Pi Connect feature sees a few tweaks, which is the feature that effectively replaces remote X-sessions. Considering how glacially slow X desktop sessions can be, this is something which can be considered an improvement, but it would be nice if there was an alternative that didn’t rely on Raspberry Pi-provided services to work.