Not-Quite-So-Hot Stuff: A Thermal Exam On The Latest Raspberry Pi

When the Raspberry Pi 4 was first launched, one of its few perceived flaws was that it had a propensity to get extremely hot. It’s evidently something the Pi people take very seriously, so in the months since they have addressed the problem with a set of firmware updates. Now they’ve taken a look at the effect of the fixes in a piece on the Raspberry Pi web site, and it makes for an interesting comparison.

The headline figure is that all updates together remove about a watt of power from the load, a significant quantity for what is still a board that can run from a capable phone charger. Breaking down the separate parts of the updates is where the meat of this story lies though, as we see the individual effects of the various USB, memory, power management and clocking updates. In temperature terms they measure an on-load drop from 72.1 °C to 58.1 °C, which should be a significant improvement for any Pi 4 owner.

There is a debate to be had over in what role a computer such as a Pi should serve. As successive revisions become ever more desktop-like in their capabilities, do they run the risk of abandoning the simplicity of a cheap Linux box as a component that makes us come back for more? It’s a possibility, but one they have very well addressed by developing the Pi Zero. They have also successfully avoided the fate of the Arduino — inexorably tied to its ATmega powered original line despite newer releases. As we have frequently said when reviewing Raspberry Pi competitors, it’s the software support that sets them apart from the herd, something this power-draw story demonstrates admirably.

Raspberry Pi 4 HDMI Is Jamming Its Own WiFi

Making upgrades to a popular product line might sound like a good idea, but adding bigger/better/faster parts to an existing product can cause unforeseen problems. For example, dropping a more powerful engine in an existing car platform might seem to work at first until people start reporting that the increased torque is bending the frame. In the Raspberry Pi world, it seems that the “upgraded engine” in the Pi 4 is causing the WiFi to stop working under specific circumstances.

[Enrico Zini] noticed this issue and attempted to reproduce exactly what was causing the WiFi to drop out, and after testing various Pi 4 boards, power supplies, operating system version, and a plethora of other variables, the cause was isolated to the screen resolution. Apparently at the 2560×1440 setting using HDMI, the WiFi drops out. While you could think that an SoC might not be able to handle a high resolution, WiFi, and everything else this tiny computer has to do at once. But the actual cause seems to be a little more interesting than a simple system resources issue.

[Mike Walters] on a Twitter post about this issue probed around with a HackRF and discovered a radio frequency issue. It turns out that at this screen resolution, the Pi 4 emits some RF noise which is exactly in the range of WiFi channel 1. It seems that the Pi 4 is acting as a WiFi jammer on itself.

This story is pretty new, so hopefully the Raspberry Pi Foundation is aware of the issue and working on a correction. For now, though, it might be best to run a slightly lower resolution if you’re encountering this problem.

Your Raspberry Pi Cluster Is Not Like This One

Many readers will have had their first taste of experimentation with cluster computing through the medium of the Raspberry Pi. The diminutive Linux capable boards can easily be hooked up as a group via a network hub, and given the right software become a whole that is greater than the sum of its parts. None of us will however have reached the heights of the Raspberry Pi cluster shown by Oracle at their Oracle OpenWorld conference, a mighty rack packing a cluster of no less than 1060 Pi 3 B+ boards. This machine is touted as a supercomputer and it’s worthy of the name, though perhaps it’s not in the same class as the elite in that field.

Getting that number of individual 3Bs into a human-sized rack is no easy feat, and they have gone for custom 3D-printed racks to hold the boards. PoE would have resulted in too much heat dissipation, so instead they use USB power from an array of large multi-way USB power supplies. A set of switches provide the networking, and a conventional server sits in the middle to provide storage and network booting.

It’s certainly a cool way to wow the crowds at a conference, but we’re unsure whether it delivers the best bang for your supercomputing buck or whether it’s more useful as a large room heater. Meanwhile you can take a look at a few more modest Pi clusters, with unusual operating systems, or slightly more adherence to convention.

Thanks [Frisco] for the tip.

A Foolproof Raspberry Pi Media Player

The media landscape in the home has changed precipitously over the years. Back in the days when torrents were king, DVD players and TVs started to sprout USB ports and various methods of playing digital videos, while hackers repurposed office machines and consoles into dedicated media boxes. [Roiy Zysman] is a fan of a clean, no-fuss approach, so built his PiVidBox along those lines.

The build, unsurprisingly, starts with a Raspberry Pi. Cheap, capable of playing most common codecs, and fitted with an HDMI port as standard, it’s a perfect platform for the job. Rather than fiddle with complex interfaces or media apps, instead, the PiVidBox uses a simple script. The Pi is configured to continually scan the /media folder for mounted devices, and play any videos it comes across. Simply pop in an SD card or USB drive, and the content starts rolling. No buttons, remotes, or keyboards needed!

It’s a interface without much flexibility, but it makes up for that in barebones simplicity. We can imagine it would come in handy for a conference room or other situation where users grow tired of messing around with configurations to get screens to work. The Raspberry Pi makes a rather excellent basis for a media player build, and we’ve seen some stunning examples in the past!

Traffic Updates On The Seven Seas: Open Source Chart Plotter Using A Raspberry Pi

As the Raspberry Pi in its various forms continues to flow into the wild by the thousands, it’s interesting to see its user base expand outside beyond the hacker communities. One group of people who’ve also started taking a liking to it is sailing enthusiasts. [James Conger] is one such sailor, and he built his own AIS enabled chart plotter for a fraction of the price of comparable commercial units.

AIS transponders in the Mediterranean. VesselFinder

Automatic Identification System (AIS) is a GPS tracking system that uses transponders to transmit a ship’s position data to other ships or receiver stations in an area. This is used for collision avoidance and by authorities (and hobbyists) to keep an eye on shipping traffic, and allow for stricken vessels to be found easily. [James]’ DIY chart plotter overlays the received AIS data over marine charts on a nice big display. A Raspberry Pi 3B+, AIS Receiver Hat, USB GPS dongle and a makes up the core of the system. The entire setup cost about $350. The Pi runs OpenCPN, an open source chart plotter and navigation software package that [John] says is rivals most commercial software. As most Pi users will know the SD card is often a weak link, so it’s probably worth having a backup SD card with all the software already installed just in case it fails during a voyage.

We’ve seen AIS receiver stations built using the RTL-SDR, as well as a number of projects around the AIS equivalent in aviation, ADS-B. Check out [John]’s video after the break. Continue reading “Traffic Updates On The Seven Seas: Open Source Chart Plotter Using A Raspberry Pi”

Raspberry Pi NAS Makes Itself At Home In Donor PC

It’s safe to say that most of us have at least one Raspberry Pi hanging from a USB cable someplace, silently hammering away at some unglamorous task that you’d rather not do on a “real” computer. With as cheap as they are, it’s not like there’s a big concern about where it sets up shop. But if you’re like [Jeremy S. Cook] and want your $35 Linux computer to be a permanent member of the family, then his tips on turning an old PC into a gloriously overkill Pi NAS may be of interest.

The main component [Jeremy] salvages from the old Lenovo desktop PC is, obviously, the case itself. Stripped of its original components, the case gives him plenty of room to mount the Pi as well as a couple of hard drives and a powered USB hub. To prevent the bottom of the Raspberry Pi from shorting out against the metal computer case, he designed and 3D printed a mount for it. Everything else is held down with hook and loop fastener, making it quick and easy to move things around and make adjustments.

While it might not be strictly necessary, [Jeremy] also took the time to salvage the computer’s old heatsink. Being far too large to fit on the Pi as-is, he ran a line down the back of it with his mill and snapped it in half. He uses a bit of thermal tape to hold the bisected heatsink onto the Pi’s SoC, with a couple pieces of electrical tape to make sure it doesn’t short out on anything.

Raspberry Pi NAS builds are exceptionally popular, and we’ve seen more than we can count over the years. You can build one out of parts from IKEA, and if you don’t mind plastic, you can always 3D print the whole thing. If you really want to go minimal, you can even hang some files on the network with little more than a Pi Zero stuck into a USB port.

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Raspberry Pi Ham Radio Remote Reviewed

One problem with ham radio these days is that most hams live where you can’t put a big old antenna up due to city laws and homeowner covenants. If you’re just working local stations on VHF or UHF, that might not be a big problem. But for HF usage, using a low profile antenna is a big deal. However, most modern radios can operate remotely. Well-known ham radio company MFJ now has the RigPi Station Server and [Ham Radio DX] has an early version and did a review.

As the name implies, the box contains a Raspberry Pi. There’s also an audio interface. The idea is to consolidate rig control along with other station control (such as rotators) along with feeding audio back and forth to the radio. It also sends Morse code keying to the radio. The idea is that this box will put your radio on the network so that you operate it using a web browser on a PC or a mobile device.

According to MFJ, you can operate voice, Morse code, or digital modes easily and remotely. The box uses open source software that can control over 200 different radios and 30 rotors. Of course, you could build all this yourself and use the same open source software, but it is nicely packaged. [Ham Radio DX] says you don’t need to know much about the Pi or Linux to use the box, although clearly you can get into Linux and use the normal applications if you’re so inclined.

Even if you don’t want to transmit, we could see a set up like this being used for remote monitoring. We’d like to see a companion box for the remote end that had the audio hardware, a keyer, and perhaps a knob to act as a remote control of sorts. Of course, you could probably figure out how to do that yourself. We wonder if some ham clubs might start offering a remote radio via an interface like this — we’ve seen it done before, but not well.

Your $50 radio probably isn’t going to work with this, and if you use FT8, you could argue you don’t need to be there anyway.

Continue reading “Raspberry Pi Ham Radio Remote Reviewed”