Bela: Real-Time BeagleBone Audio/Analog Cape

April 13, 2016 by 16 Comments

Bela is a cape for the BeagleBone Black that’s aimed at artists and musicians. Actually, the cape is much less than half of the story — the rest is in some clever software and a real-time Linux distribution. But we’re getting ahead of ourselves. Let’s talk hardware first.

First off, the cape has stereo input and output as well as two amplified speaker outs. It can do all of your audio stuff. It also has two banks of analogue inputs and outputs, each capable of handling eight signals. In our opinion, this is where the Bela is cool. In particular, the analog outputs are not Arduino-style “analog outputs” where it’s actually a digital output on which you can do PWM to fake an analog signal. These are eight 16-bit outputs from an AD5668 DAC which means that you can use the voltages directly, without filtering.

Then there’s the real trick. All of these input and output peripherals are hooked up to the BeagleBone’s Programmable Realtime Units (PRUs) — a hardware subsystem that’s independent of the CPU but can work along with it. The PRU is interfaced with the real-time Linux core to give you sub-microsecond response in your application. This is a big deal because a lot of other audio-processing systems have latencies that get into the tens of milliseconds or worse, where it starts to be perceptible as a slight lag by humans.

The downside of this custom analog and audio I/O is that it’s not yet supported by kernel drivers, and you’ll need to use their “Heavy Audio Tools” which compiles Pd programs into C code, which can then drive the PRUs. Of course, you can write directly for the PRUs yourself as well. If you just want to play MP3s, get something you have a bunch of simpler, better options. If you need to do responsive real-time audio installations, Bela is a way to go.

The project is open-source, but we had to do a bunch of digging to find what we were looking for. The hardware is in zip files here, and you’ll find the software here. The demo projects look/sound pretty cool and their Kickstarter is long over-funded, so we’re interested to see what folks make with these.

Introducing The BeagleBone Blue

January 11, 2016 by 37 Comments

The BeagleBone is a board that doesn’t get a lot of attention in a world of $5 Raspberry Pis, $8 single board computers based on router chipsets, and a dizzying array of Kickstarter projects promising Android and Linux on tiny credit card-sized single board computers. That doesn’t mean the BeagleBone still isn’t evolving, as evidenced by the recent announcement of the BeagleBone Blue.

The BeagleBone Blue is the latest board in the BeagleBone family, introduced last week at CES. The Blue is the result of a collaboration between UCSD Engineering and TI, and with that comes a BeagleBone built for one specific purpose: robotics and autonomous vehicles. With a suite of sensors very useful for robotics and a supported software stack ideal for robots and drones, the BeagleBone Blue is the perfect board for all kinds of robots.

On board the BeagleBone Blue is a 2 cell LiPo charger with cell balancing and a 6-16 V charger input. The board also comes with eight 6V servo outputs, four DC motor outputs and inputs for four quadrature encoders. Sensors include a nine axis IMU and barometer. Unlike all previous BeagleBones, the BeagleBone Blue also comes with wireless networking: 802.11bgn, Bluetooth 4.0 and BLE. USB 2.0 client and host ports are also included.

Like all of the recent BeagleBoards, including the recently released BeagleBone Green, the Blue uses the same AM3358 1 GHz ARM Cortex 8 CPU, features 512 MB of DDR3 RAM, 4GB of on board Flash, and features the main selling point of the BeagleBoard, two 32-bit programmable real-time units (PRUs) running at 200 MHz. The PRUs are what give the BeagleBone the ability to blink pins and control peripherals faster than any other single board Linux computer, and are extremely useful in robotics, the Blue’s target use.

Right now, the BeagleBone Blue isn’t available, although we do know you’ll be able to buy one this summer. Information on pricing and availability – as well as a few demos – will come in February.

BeagleBone Green Hands-On: Lower Price, Same Horsepower

August 5, 2015 by 68 Comments

Although the BeagleBone Green was announced at the Bay Area Maker Faire last May, there hasn’t been much said about it on the usual forums and IRC channels. Now, it’s finally out and I got my hands on one of them. Through a cooperation between the BeagleBoard foundation and Seeed Studios, the best small Linux board for doing real work with small Linux boards is now cheaper, a little more modern, and green.

The BeagleBone Green is an update to the venerable BeagleBone Black, the dev board based on a TI ARM Cortex-A8. It’s an extremely capable machine with a few interesting features that make it the perfect device for embedded applications. With the BeagleBone Green, the BB Black gets a small hardware refresh and a drastic reduction in price. If you want to do real work on a Linux board, this is the one to get. Check out the review below for everything that’s been updated, everything that’s the same, and why this is one of the most interesting developments in small Linux boards in recent memory.

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Hackaday Prize Entry: A BeagleBone Logic Analyzer

May 19, 2015 by 10 Comments

If you have a BeagleBone, you already have a lot of tools. We’ve seen them used in driving hundreds of LEDs at a very high frame rate, used as a video card for ancient computers, and as a software defined radio. For his entry to The Hackaday Prize, [Kumar] turned his BeagleBone into a 14-channel, 100Msps logic analyzer that’s good enough to debug just about all those hobby electronics projects you’re working on.

The BeagleBone is only able to have this sort of performance as a logic analyzer because of its PRUs, those fancy peripherals that make the Beagle great at blinking pins really, really fast. [Kumar] is using both PRUs in the BeagleBone for this project. PRU1 reads from the input probes, and PRU0 writes all the samples into DDR memory directly. From there, the samples are off to kernel modules and apps, either sigrok, dd, or something you coded up in Python.

Compared to the cheap logic analyzers we have today like the Salae Logic and the DSLogic, [Kumar]’s project is just as good as any commercial offering (provided you can live with 14 channels instead of 16), and because it’s based on a BeagleBone, the software is infinitely expandable.

UPDATE: After this post was written but before it was published, [Kumar] finished up a blog post on how he’s building a logic analyzer with the BeagleBone’s PRUs. It’s a true tutorial, with enough code demos to allow anyone to build their own 8-bit analyzer on a BeagleBone, and there are more updates coming.

The 2015 Hackaday Prize is sponsored by:

BeagleBones At MRRF

March 22, 2015 by 7 Comments

[Jason Kridner] – the BeagleBone guy – headed out to the Midwest RepRap Festival this weekend. There are a lot of single board computers out there, but the BeagleBoard and Bone are perfectly suited for controlling printers, and motion control systems thanks to the real-time PRUs on board. It’s not the board for you if you want to play retro video games or build a media center; it’s the board for building stuff.

Of interest at the BeagleBooth were a few capes specifically designed for CNC and 3D printing work. There was the CRAMPS, a clone of the very popular RAMPS 3D printer electronics board made for the Beagle. If you’re trying to control an old mill that is only controllable through a parallel port, here’s the board for you. There are 3D printer boards with absurd layouts that work well as both printer controller boards and the reason why you should never come up with the name of something before you build it.

[Jason]’s trip out to MRRF wasn’t only about extolling the virtues of PRUs; Machinekit, a great motion control software, was also there, running on a few Beagles. The printer at the BeagleBooth was running Machinekit and apart from a few lines of GCode that sent the head crashing into the part, everything was working great.

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Turn Your BeagleBoneBlack In To A 14-channel, 100Msps Logic Analyzer

February 19, 2015 by 34 Comments

The BeagleBoneBlack is a SoC of choice for many hackers – and quite rightly so – given its powerful features. [abhishek] is majoring in E&E from IIT-Kharagpur, India and in 2014 applied for a project at beagleboard.org via the Google Summer of Code project (GSoC). His project, BeagleLogic aims to realize a logic analyzer using the Programmable Real-Time units on board the AM335X SoC family that powers the BeagleBone and the BeagleBone Black.

The project helps create bindings of the PRU with sigrok, and also provides a web-based front-end so that the logic analyzer can be accessed in much the same way as one would use the Cloud9 IDE on the BeagleBone/BeagleBone Black to create a new application with BoneScript.

Besides it’s obvious use as a debugging tool, the logic analyzer can also be a learning tool that can be used to understand digital signals. BeagleLogic turns the BeagleBone Black into a 14-channel, 100Msps Logic Analyzer. Once loaded, it presents itself as a character device node /dev/beaglelogic. In stand-alone mode, it can do binary captures without any special client software. And when used in conjunction with the sigrok library, BeagleLogic supports software triggers and decoding for over 30 different digital protocols.

The analyzer can sample signals from 10Hz upto 100MHz, in 8 or 16 bits and up to a maximum of 14 channels. Sample depth depends on free RAM, and upto 320MB can be reserved for BeagleLogic. There’s also a web interface, which, once installed on the BeagleBone, can be accessed from port 4000 and can be used for low-volume captures (up to 3K samples).

[abhishek] recently added the BeagleLogic Cape which can be used to debug logic circuits up to 5V safely. Source files for BeagleLogic as well as the Cape are available via his github repos. [abhishek] blogged about his project on his website where there’s a lot more information and links to be found. Catch a video of BeagleLogic after the break.

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FOSDEM 2023: An Open-Source Conference, Literally

March 1, 2023 by 6 Comments

Every year, on the first weekend of February, a certain Brussels university campus livens up. There, you will find enthusiasts of open-source software and hardware alike, arriving from different corners of the world to meet up, talk, and listen. The reason they all meet there is the conference called FOSDEM, a long-standing open-source software conference which has been happening in Belgium since 2000. I’d like to tell you about FOSDEM because, when it comes to conferences, FOSDEM is one of a kind.

FOSDEM is organized in alignment with open-source principles, which is to say, it reminds me of an open-source project itself. The conference is volunteer-driven, with a core of staff responsible for crucial tasks – yet, everyone can and is encouraged to contribute. Just like a large open-source effort, it’s supported by university and company contributions, but there’s no admission fees for participants – for a conference, this means you don’t have to buy a ticket to attend. Last but definitely not least, what makes FOSDEM shine is the community that it creates.

FOSDEM’s focus is open software – yet, for hackers of the hardware world, you will find a strong hardware component to participate in, since a great number of FOSDEM visitors are either interested in hardware, or even develop hardware-related things day-to-day. It’s not just that our hardware can’t live without software, and vice-versa – here, you will meet plenty of pure software, a decent amount of pure hardware, and a lot of places where the two worlds are hard to distinguish. All in all, FOSDEM is no doubt part of hacker culture in Europe, and today, I will tell you about my experience of FOSDEM 2023. Continue reading “FOSDEM 2023: An Open-Source Conference, Literally” →