An Introduction To The BeagleBone PRU

BBB While the BeagleBone is usually compared to the Raspberry Pi, there are a few features that make the ‘Bone a vastly more capable single board computer. There is a small difference in the capabilities of the processor, but the real power of the BeagleBone comes from the PRUs available: two small cores that give the BeagleBone the hardware equivalent of bitbanging pins. [Texane] has put up two great tutorials for using the PRU in the BeagleBone that should be required reading for every BeagleBone owner.

The first tutorial goes over the capabilities of the PRUs in the BeagleBone and setting up the software environment to develop your own hardware interfaces with the PRU. While writing code for the PRU has usually involved the Beagleboard packages, TI has recently released a version of Code Composer Studio that gives the option to compile C code for the PRU.

[Texane] used this C compiler to rehash the earlier, assembly only PRU program, making development significantly easier. There’s still a bit of inline assembly, and the inline assembly support isn’t as advanced as in GCC, but it’s still much easier than the assembly only variant.

While [Texane] is using the PRU in his BeagleBone to develop something at a synchrotron facility, three are a few things where really fast hardware bitbanging comes in handy: it can be used to make a video card for a vintage mac, or any sort of VGA video card, really. Very cool stuff, especially now that you can write something in C.

BeagleBone Blacks Still Not Available, Here’s Blue Steel


The BeagleBone Black has been featured in an improbable number of awesome project, ranging from driving thousands of LEDs for a video display, to 3D printer controller boards. There’s a lot you can do with a tiny Linux board that’s much more powerful than the Raspberry Pi – if you can find one, that is. The BeagleBone Black has been out of stock everywhere for months now, with little sign of when distributors will receive some new stock.

Luckily, the BeagleBone Black is open source. Anyone can make them. Finally, someone did. It’s called Blue Steel, and notwithstanding the inevitable Zoolander references, it’s pretty much the same as the BeagleBone Black we all know and love.

There are a few differences between Blue Steel and the BeagleBone Black: Blue Steel doesn’t have an HDMI output, and the 4GB of on-board Flash featured on the BeagleBone isn’t found on Blue Steel. Still, it has the same processor, same amount of RAM, and the same connectors found in the BeagleBone Black.

You can pre-order Blue Steel here, with the boards eventually shipping at the end of the month. It’s the same price as the BeagleBone Black, not ideal considering the missing HDMI port and Flash storage. Still, you can actually buy it now, something you can’t say about the BeagleBone.

Mini Ms. Pacman

MsThe bragging rights of owning a vintage arcade machine are awesome, but the practicality of it – restoring what is likely a very abused machine, and the sheer physical space one requires – doesn’t appeal to a lot of people. [Jason] has a much better solution to anyone who wants a vintage arcade machine, but doesn’t want the buyer’s remorse that comes with the phrase, “now where do we put it?” It’s a miniaturized Ms. Pacman, mostly scale in every detail.

The cabinet is constructed out of 1/8″ plywood, decorated with printed out graphics properly scaled down from the full-size machine. Inside is a BeagleBone Black with a 4.3″ touchscreen, USB speakers, and a battery-backed power supply.

The control system is rather interesting. Although [Jason] is using an analog joystick, the resistive touch screen monopolizes the ADC on the BeagleBone. The solution to this problem would be to write a driver, or if you’re [Jason], crack the joystick open and scratch away the resistive contact until you have a digital joystick. A nice solution, considering Ms. Pacman doesn’t use an analog joystick anyway.

Pictures over on [Jason]’s G+ page, along with a vertical video that G+ displays properly. Thanks, Google.

Aluminum LED Matrix Looks Professionally Made


[David Donley] has wanted to make a LED matrix for a while now, and has decided to finally pull the trigger — after all, that many LEDs certainly aren’t cheap!

He’s using a set of 16 Adafruit 8×8 NeoPixel LED Matrices (almost $600 worth of LEDs) and a BeagleBone Black to control them. To mount the LED matrices he bought a sheet of 6061-T6 aluminum for two purposes — one to act as a giant heatsink, and two, to look cool. All he had to do was drill some holes in the sheet for the connectors, and then use 3M 300LSE double-sided adhesive to stick the NeoPixels to the surface. The result is a border-less display that looks clean and professional.

To power the array he’s using a 5V 90A power supply — at full brightness these LEDs can consume around 325W, or 65A at 5V!  Taking notes from the opensource LEDscape code on GitHub he’s made his own software to control the display — stick around after the break to see it in action.

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BeagleBone Black + RAMPS


The BeagleBone Black, with an impressive amount of computing power and a whole bunch of I/O, would make an impressive CNC controller, save for two shortcomings: The BBB isn’t in stock anywhere, and CNC capes are a little on the pricey side. [Marc Peltier] can’t do anything about finding a distributor that doesn’t have the BeagleBone on backorder for you, but he did come up with an adapter for the very popular RAMPS-FD 3D printer controller board (Forum, French, Here’s the Google translation matrix).

The RAMPS-FD is an extension of the RAMPS board and a shield for the Arduino Due. Both the Due and BBB work on 3.3 V, meaning controlling the RAMPS-FD is simply a matter of finding the correct wiring diagram and pin assignments on the BeagleBone. [Marc] solved this problem by using the settings from the BeBoPr cape and using the existing BeBoPr LinuxCNC configuration.

The end result of [Marc]’s tinkering is something a lot like [Charles Steinkueler]’s CNC capes for the BeagleBone Black we saw at the Midwest RepRap Fest. [Charles] isn’t selling his capes, but no one else seems to be selling BeagleBone Blacks, either.

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MRRF: ARM-Based CNC Controllers


8-bit microcontrollers are the standard for RepRap electronics, but eventually something better must come along. There has been a great deal of progress with ARM-based solutions, and of course a few of these made a showing at the Midwest RepRap Festival.

First up is [Mark Cooper], creator of Smoothieboard, the ultimate RepRap and CNC controller. It’s an ARM Cortex-M3 microcontroller with Ethernet, SD card, and up to five stepper drivers. It had a Kickstarter late last year and has just finished shipping all the rewards to the backers. In our video interview, [Mark] goes over the functions of Smoothieboard and tells us about some upcoming projects: the upcoming Smoothiepanel will feature a graphic LCD, SD card, rotary encoder and buttons, all controlled over USB by the Smoothieboard.

Next up is [Charles] with a whole bunch of CNC capes for the Beaglebone. By far the most impressive board was a huge I/O expander, motor driver, and everything controller for a Beaglebone featuring – get this – three parallel port interfaces. This was a one-off board costing thousands of dollars, but [Charles] did show off a few smaller and more practical boards for Beaglebone CNC control. Here’s a link to [Charles]’ capes.

Videos below.

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The 30th Anniversary Macintosh

It’s been just over thirty years since the original Macintosh was released, and [hudson] over at NYC Resistor thought it would be a good time to put some old hardware to use. He had found an all-in-one Mac SE “on the side of a road” a while ago (where exactly are these roads, we wonder), and the recent diamond anniversary for the original mac platform convinced him to do some major hardware hacking.

Inspired by a six-year-old project from a NYC Resistor founder aptly named the 24th anniversary Mac, [hudson] decided to replace the old hardware with more powerful components – in this case, a BeagleBone Black. Unlike the earlier build, though, the original CRT would be salvaged; the analog board on the Mac SE has pins for video, hsync, vsync, and power.

To get a picture on the old CRT, [hudson] needed to write a software video card that used the BeagleBone’s PRU. The CRT isn’t exactly “modern” tech, and everything must be clocked at exactly 60.1 Hz lest the CRT emit a terrible buzzing sound.

With a software video card written for the old CRT, the BeagleBone becomes the new brains of this beige box. It runs all the classic Linux GUI apps including XEyes and XScreenSaver, although flying toasters might be out of the question. He also managed to load up the Hackaday retro site with xterm, making this one of the best ways to make an old Mac SE useful.