Hot Swappable Raspberry Pi Rack

The Raspberry Pi has inspired many a hacker to take the inexpensive (~$35) microcomputer to the enterprise level. From bitcoin miners to clusters, the Raspberry Pi has found itself at the heart of many large-scale projects.

On hackaday.io [Dave] served up his own contribution with his Raspberry Pi Rack. Inspired by enterprise blade servers, he wanted to house multiple Raspberry Pi boards in a single enclosure providing power and Ethernet. The spacing between the blades and the open sides allow for each Pi to cool without the additional power and cost of fans.

Starting with an ATX power supply and Ethernet switch, Dave created a base that housed the components that would be shared by all the Pis. Using a 3D model of a Pi he found online, he began working on the hotswap enclosures. After “dozens of iterations” he created a sled that would hold a Pi in place with clips rather than screws and slide into his rack to connect to power and Ethernet.

Like most projects, some mistakes were made along the way. In his write up [Dave] describes how after printing the bottom plate he realized he hadn’t accounted for the holes for the Ethernet cable runs. Instead the cables run along the back wall in a way he now prefers.

You can find all the details and download the 3D models on his project page.

SPARC: A Voice Controlled Robot Sings Sweetly in DTMF

One of the recurring themes of science fiction is the robot. From such icons as C-3PO and R2D2 in Star Wars to WALL-E and Eve, robots have always had a certain appeal. Inexpensive microcontrollers like the Arduino have opened up the world of robotics to more people. [JohnFin] has done just this. By linking two Arduinos as the brain, he has created a voice controlled robot he calls S.P.A.R.C. (Sentry/Project Assistant/Robot Companion).

It began when he received a robotic arm for Christmas and was disappointed by it. Instead of simply building a better arm, he got “carried away” and built an entire robot instead. The entire project took three months, most of which he spent learning programming.

SPARC has three sonar sensors for detecting obstacles and movement, an arm and a couple of interchangeable hands for holding objects, and an EasyVR Arduino Shield for the voice control. The robot’s “eyes” are an LED ‘KITT’ scanner and an AN6884 VU meter chip that flashes the “eyes” when the robot speaks. It carries an onboard smartphone to look up weather, play music from the phone’s SD card, and GPS functions.

SPARC can respond to a range of commands and games including “follow me” and “singing.” [JohnFin] has also added a “sequencer” function to record and playback a series of commands. A video of this feature can be found after the break.

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