Raspberry Pi Creates Melody

March 28, 2022 by 2 Comments

For those who are not into prog rock in the 70s or old radio shows from the 40s, the Theremin may be an unfamiliar musical instrument. As a purely electronic device, it’s well outside the realm of conventional musical instruments. Two radio antennas detect the position of the musician’s hands to make a unique sound traditionally associated with eeriness or science fiction.

Normally a set of filters and amplifiers are used to build this instrument but this build instead replaces almost everything with a Raspberry Pi Zero 2, and instead of radio antennas to detect the position of the musician’s hands a set of two HC-SR04 distance sensors are used instead. With the processing power available from the Pi, the modernized instrument is able to output MIDI as well which makes this instrument easily able to interface with programs like GarageBand or any other MIDI-capable software.

The project build is split into two videos, the second of which is linked below. The project code is also available on the project’s GitHub page, so anyone with the Pi and other equipment available can easily start experimenting with this esoteric and often overlooked musical instrument. It’s been around for over 100 years now, and its offshoots (including this build) are as varied as the sounds they can produce.

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Get GitHub Tickets IRL With A Raspberry Pi And A Receipt Printer

March 25, 2022 by 15 Comments

Thermal receipt printers are finding their way into all sorts of projects that are well beyond the point-of-sale environment that they normally inhabit. And while we applaud all the creative and artistic uses hackers have found for these little gems, this GitHub physical ticket printer has to be the best use for one yet.

According to [Andrew Schmelyun], seeing a fast-food order pop up on a thermal printer was the inspiration for this build. Maintaining over one hundred GitHub repos as he does, it’s easy for the details of any one bug report or feature request to get lost in the swarm of sticky notes that [Andrew] previously used to keep track of his work. To make it happen, he teamed an Epson thermal printer up to a Raspberry Pi Zero W and worked out the details of sending data to the printer using PHP. Luckily, there’s a library for that — the beauty of GitHub.

With the “Hello, World!” bit out of the way, [Andrew] turned his attention to connecting to GitHub. He set up some webhooks on the GitHub side to send a POST request every time an issue is reported on one of his repos. The POSTs are sent via ngrok to a PHP web server running on the Pi, which formats the data and sends the text to the printer. There’s a short video in the tweet below.

Between the sound of the printer working and the actual dead-tree ticket, it’ll be hard for [Andrew] to miss issues now. We’ve seen thermal printers stuffed into cameras, used to send pictures to Grannie, and even watched them commit suicide slowly, but we say hats off to [Andrew] for his solid work ethic and a fun new way to put a receipt printer to use.

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Raspberry Pi And The Story Of SD Card Corruption

March 9, 2022 by 107 Comments

Tales of Raspberry Pi SD card corruption are available online by the fistful, and are definitely a constant in Pi-adjacent communities. It’s apparent that some kind of problems tend to arise when a Raspberry Pi meets an SD card – which sounds quite ironic, since an SD card is the official and recommended way of booting a Pi. What is up with all of that?

I can start with a history lesson. Back when Raspberry Pi launched in 2012 – which is now 10 years ago – there were SD card controller driver problems, which makes sense given the wide variety of SD cards available out there. They were verifiably fixed one by one at some point in time, as debugging goes, their impact decreased and bugs with individual cards got smoothed over. This is how the “Pi SD card corruption” meme was originally born; however, if the problems were to end there, so would the meme. Yet, tales of broken SD cards plague us to this day – way less severe than they were in the beginning, but pronounced enough that you’ll see people encounter them every now and then.

Over the years, a devoted base of Pi SD card haters has grown. Their demand has been simple – Raspberry Pi has to get an ability to boot from something else, in large part because of corruption reasons, but also undeniably because of speed and capacity/cost limitations of SD cards. Thanks to their demands and work, we’ve seen a series of projects grow from unofficial efforts and hacks into officially supported Raspberry Pi abilities – USB boot being initially more of a workaround but now something you can enable out of the box, SSD-equipped Pi enclosures becoming more of a norm, and now, NVMe boot appearing on the horizon. Every few years, we get a new way to boot a Pi. Continue reading “Raspberry Pi And The Story Of SD Card Corruption” →

It’s Official! The Raspberry Pi Is Now 10!

February 28, 2022 by 100 Comments

In any given field there are epoch-defining moments, those events after which nothing was quite the same as it had been before. It’s been a decade since the launch of the first Raspberry Pi single board computer. This was by no means the first inexpensive computer board, nor was it the first to support the GNU/Linux operating system, but it was among the first to promise a combination of those two. Coupled with support from a crop of British 8-bit alumni meant that from when it first gained publicity in early 2011 it garnered a huge buildup of interest.

We were first teased with a USB stick style prototype, which morphed into a much larger Raspberry Pi alpha board and finally into pre-production boards much closer to the model launched at the end of February ten years ago.

How To Disappoint Every Single British Geek At 6 AM

An array of Pi prototype boards pictured on display at the Cambridge University Computer Laboratory.
An array of Pi prototype boards pictured on display at the Cambridge University Computer Laboratory.

Pedants will claim that the 10th birthday of the Pi is technically not yet upon us because those first Model B boards went on sale on the 29th of February 2012, a leap day. The two distributors, RS and Farnell, were both putting them on sale with the expectation of selling around 10,000 units — a prediction that proved woefully inadequate, with both websites collapsing under the weight of would-be Pi-purchasers within seconds of opening up at 6 AM.

I was ready to order at 6 AM, and was only able to order mine halfway through the day. That short wait would be just the beginning — because they received so many more orders than anticipated, the bulk of the orders weren’t fulfilled until May. Nobody had imagined how wildly successful the Pi boards would become. Continue reading “It’s Official! The Raspberry Pi Is Now 10!” →

A 64-Bit Raspberry Pi OS At Last

February 4, 2022 by 42 Comments

Long-term Raspberry Pi watchers will have seen a lot of OS upgrades in their time, from the first Debian Squeeze previews through the Raspbian years to the current Raspberry Pi OS. Their latest OS version is something different though, and could be one of the most important releases in the platform’s history so far, as finally there’s an official release of a 64-bit Raspberry Pi OS.

Would-be 64-bit Pi users have of course had the chance to run 64-bit GNU/Linux operating system builds from other distributions for nearly as long as there have been Pi models with 64-bit processors, but until now the official distribution has only been available as a 32-bit build. In their blog post they outline their reasons for this move in terms of compatibility and performance, and indeed we look forward to giving it a try.

Aside from being a more appropriate OS for a 64-bit Pi, this marks an interesting moment for the folks from Cambridge in that it is the first distribution that won’t run on all Pi models. Instead it requires a Pi 3 or better, which is to say the Pi 3, Zero 2 W, Pi 4, Pi 400, and the more powerful Compute Modules. All models with earlier processors including the original Pi, Pi Zero, and we think the dual-core Pi 2 require a 32-bit version, and while the Pi Zero, B+ and A+ featuring the original CPU are still in production this marks an inevitable move to 64-bit in a similar fashion to that experienced by the PC industry a decade or more ago.

As far as we know the Zero is still flying off the shelves, but this move towards an OS that will leave it behind is the expected signal that eventually there will be a Pi line-up without the original chip being present. We’re sure the 32-bit Pi will be supported for years to come, but it should be clear that the Pi’s future lies firmly in the 64-bit arena. They’ve retained their position as the board to watch oddly not by always making the most impressive hardware but by having the most well-supported operating system, and this will help them retain that advantage by ensuring that OS stays relevant.

On the subject of the future course of the Pi ship, our analysis that the Compute Module 4 is their most exciting piece of hardware still stands.

A pinout diagram of the new Pi 4, showing all the alternate interfaces available.

Did You Know That The Raspberry Pi 4 Has More SPI, I2C, UART Ports?

February 1, 2022 by 35 Comments

We’ve gotten used to the GPIO-available functions of Raspberry Pi computers remaining largely the same over the years, which is why it might have flown a little bit under the radar: the Raspberry Pi 4 has six SPI controllers, six I2C controllers, and six UARTs – all on its 40-pin header. You can’t make use of all of these at once, but with up to four different connections wired to a single pin you can carve out a pretty powerful combination of peripherals for your next robotics, automation or cat herding project.

The datasheet for these peripherals is pleasant to go through, with all the register maps nicely laid out – even if you don’t plan to work with the register mappings yourself, the maintainers of your preferred hardware enablement libraries will have an easier time! And, of course, these peripherals are present on the Compute Module 4, too. It might feel like such a deluge of interfaces is excessive, however, it lets you achieve some pretty cool stuff that wouldn’t be possible otherwise.

Having multiple I2C interfaces helps deal with various I2C-specific problems, such as address conflicts, throughput issues, and mixing devices that support different maximum speeds, which means you no longer need fancy mux chips to run five low-resolution Melexis thermal camera sensors at once. (Oh, and the I2C clock stretching bug has been fixed!) SPI interfaces are used for devices with high bandwidth, and with a few separate SPI ports, you could run multiple relatively high-resolution displays at once, No-Nixie Nixie clock style.

As for UARTs, the Raspberry Pi’s one-and-a-half UART interface has long been an issue in robotics and home automation applications. With a slew of devices like radio receivers/transmitters, LIDARs and resilient RS485 multi-drop interfaces available in UART form, it’s nice that you no longer have to sacrifice Bluetooth or a debug console to get some fancy sensors wired up to your robot’s brain. You can enable up to six UARTs. Continue reading “Did You Know That The Raspberry Pi 4 Has More SPI, I2C, UART Ports?” →

ESP32 And Raspberry Pi Take Over Game Boy LCD

January 30, 2022 by No comments

The Nintendo Game Boy and its many permutations represent one of the most well-known and successful gaming platforms ever produced. There was a decades-long stretch of time where the most popular kid in the lunch room was the one who brought in their Game Boy so the rest of the class could huddle around and check out the latest Pokemon title.

But those days are long gone, and now these once-coveted handhelds can be had for a song on the second-hand market. Which makes it the perfect time to check out this project [kgsws] released recently that allows you to interface the Game Boy LCD with the ESP32 or the Raspberry Pi. In the most basic of applications, it lets you push video from your Linux computer out to the Game Boy LCD over WiFi. But as the video below illustrates, that’s just the tip of the iceberg.

With the ESP32 wired between the handheld’s LCD and main PCB, the microcontroller can also act as a capture device using I2S camera mode. Compared to what ends up showing on the handheld’s LCD, the recorded gameplay [kgsws] shows off looks fantastic. Visuals are crisp and fluid, and naturally devoid of the Game Boy’s iconic (if slightly nauseating) greenish tint.

The project also includes the capability to control an array of Game Boy LCDs, which allows for some interesting possibilities. The image can be stretched to cover multiple displays, which [kgsws] demonstrates by playing a game on 3 x 3 grid of salvaged panels, but each LCD also can be controlled individually as is the case with the large digital clock seen above.

Whether you’re looking for a way to capture gameplay on the real hardware, or want to run RetroPie on a real Game Boy screen, we’re excited to see what folks come up with using this project.

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