raspberry pi

1651 Articles

Raspberry Pi Hive Mind

August 29, 2016 by 34 Comments

Setting up a cluster of computers used to be a high-end trick used in big data centers and labs. After all, buying a bunch of, say, VAX computers runs into money pretty quickly (not even counting the operating expense). Today, though, most of us have a slew of Raspberry Pi computers.

Because the Pi runs Linux (or, at least, can run Linux), there are a wealth of tools out there for doing just about anything. The trick is figuring out how to install it. Clustering several Linux boxes isn’t necessarily difficult, but it does take a lot of work unless you use a special tool. One of those tools is Docker, particularly Docker Swarm Mode. [Alex Ellis] has a good video (see below) showing the details of a 28 CPU cluster.

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Hackaday Links: August 28, 2016

August 28, 2016 by 19 Comments

E-paper looks awesome, but it’s a pain to work with. You need only look at the homebrew implementations of e-paper drivers and the mess of SMD components for proof of that. [jarek] wanted to play around with e-paper and developed this tiny little driver for a Teensy. It’s a fun toy, and the simplest possible circuit necessary to drive this particular e-paper module.

I am once again asking if anyone knows where to buy this computer case. No, not a complete system – I just want the case, folding keyboard, and monitor integrated into an mATX enclosure.

Back in 1985, a young [Matthias Wandel] built a remote control forklift out of a few windshield wiper motors, wood, and not much else. He’s rebuilt this toy recently, just to prove you can build anything with a stack of plywood and a wood gear template generator.

More Adafruit muppets they probably can’t call muppets. Yaaay. This time it’s J is for Joule. Watts that? A second.

The Raspberry Pi Project, one of our favorite projects in the Hackaday Prize that uses a Raspberry Pi, one of the most liked, viewed, and followed projects on Hackaday.io, and a technological tour de force the likes of which have not been seen since the invention of the steam engine got an update this week. [Arsenijs] and the rest of the Raspberry Pi Project team have released a version of their Raspberry Pi pinout helper. Previously, this tool was only used internally to the project, but since this pinout helper has such far-reaching utility they’ve decided to release a public version. Truly, they are kings among men.

This is possibly the coolest use of stacked plywood I’ve ever seen. It’s a spiral staircase, with each step made of 12 layers of plywood. The ‘spine’ of this staircase is a 3″ sch 40 steel pipe, with a proper foundation. The layer of ply are adhered to the pipe with construction adhesive, and each layer of ply is glued together with wood glue. No, it’s not up to code yet, but it was cheaper to build than just buying a spiral staircase.

[Brek] wrote a graphics library for the ubiquitous 128×64 monochromatic LCDs. It’s written for PICs, but damned if we can’t find a link to the library itself. Hopefully [Brek] will jump in the comments below.

Those really, really cheap ESP8266 modules only have 512kB of Flash in them. Here’s how you upgrade those modules to 4MB. You can do it without a hot air gun, and all you need is a few cheap Flash chips.

Here’s a sound card for a Raspberry Pi. No, that’s not a completely dumb idea. This sound card uses quality op-amps, 24-bit ADCs and DACs, and has MIDI. If you’re experimenting with Pure Data or any other Linux audio toy, this could be a useful addition to your Pi stack.

Weather-aware Shoe Rack Helps You Get Ready For The Day

August 27, 2016 by 8 Comments

If you’re anything like us, your complete shoe collection consists of a pair of work boots and a pair of ratty sneakers that need to wait until the next household haz-mat day to be retired. But some people have a thing for shoes, and knowing which pair is suitable for the weather on any given day is such a bother. And that’s the rationale behind this Raspberry Pi-driven weather-enabled shoe rack.

The rack itself is [zealen]’s first woodworking project, and for a serious shoeaholic it’s probably too small by an order of magnitude. But for proof of principle it does just fine. The rack holds six pairs, each with an LED to light it up. A PIR sensor on the top triggers the Raspberry Pi to light up a particular pair based on the weather, which we assume is scraped off the web somehow. [zealen] admits that the fit and finish leave a bit to be desired, but for a first Rasp Pi project, it’s pretty accomplished. There’s plenty of room for improvement, of course – RFID tags in the shoes to allow them to be placed anywhere in the rack springs to mind.

[via r/raspberry_pi]

Roomba Now Able To Hunt Arnold Schwarzenegger

August 27, 2016 by 13 Comments

Ever since the Roomba was invented, humanity has been one step closer to a Jetsons-style future with robots performing all of our tedious tasks for us. The platform is so ubiquitous and popular with the hardware hacking community that almost anything that could be put on a Roomba has been done already, with one major exception: a Roomba with heat vision. Thanks to [marcelvarallo], though, there’s now a Roomba with almost all of the capabilities of the Predator.

The Roomba isn’t just sporting an infrared camera, though. This Roomba comes fully equipped with a Raspberry Pi for wireless connectivity, audio in and out, video streaming from a webcam (and the FLiR infrared camera), and control over the motors. Everything is wired to the internal battery which allows for automatic recharging, but the impressive part of this build is that it’s all done in a non-destructive way so that the Roomba can be reverted back to a normal vacuum cleaner if the need arises.

If sweeping a just the right time the heat camera might be the key to the messy problem we discussed on Wednesday.

The only thing stopping this from hunting humans is the addition of some sort of weapons. Perhaps this sentry gun or maybe some exploding rope. And, if you don’t want your vacuum cleaner to turn into a weapon of mass destruction, maybe you could just turn yours into a DJ.

Kinect And Raspberry Pi Add Focus Pulling To DSLR

August 27, 2016 by 19 Comments

Prosumer DSLRs have been a boon to the democratization of digital media. Gear that once commanded professional prices is now available to those on more modest budgets. Not only has this unleashed a torrent of online content, it has also started a wave of camera hacks and accessories, like this automatic focus puller based on a Kinect and a Raspberry Pi.

For [Tom Piessens], the Canon EOS 5D has been a solid platform but suffers from a problem. The narrow depth of field possible with DSLRs makes it difficult to maintain focus on subjects that are moving relative to the camera, making follow-focus scenes like this classic hard to reproduce. Aiming for a better system than the stock autofocus, [Tom] grafted a Kinect sensor and a stepper motor actuator to a Raspberry Pi, and used the Kinect’s depth map to drive the focus ring. Parts are laser-cut, including a nice enclosure for the Pi and display that makes the whole thing reasonably portable. The video below shows the focus remaining locked on a selected region of interest. It seems like movement along only one axis is allowed; we’d love to see this system expanded to follow a designated object no matter where it moves in the frame.

If you’re in need of a follow-focus rig but don’t have a geared lens, check out these 3D-printed lens gears. They’d be a great complement to this backwoods focus-puller.

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Multi Sensor Security Camera Has You Covered

August 21, 2016 by 14 Comments

Security in the home — especially a new home — is a primary concern for many. There are many options for security systems on the market, but for those will the skills, taking matters into your own hands can add peace of mind when protected by a system of one’s own design. [Armagan C.] has created  their near-ideal multi-sensor security module to keep a watchful eye out for would-be burglars.

Upgrading from their previous Arduino + Ethernet camera — which loved to trigger false alarms — [Armagan] opted for a used Raspberry Pi model B+ camera module and WiFi connection this time around. They also upgraded the unit with a thermal sensor, LPG & CO2 gas sensor, and a motion tracking alarm. [Armagan] has also set up a live streaming  feature that records video in 1hr segments — deleting them daily — and circumvented an issue with file descriptor leak by using a crashed drone’s flight controller to route the sensor data via serial port. It is also proving superior to conventional alarms because the custom software negates the need to disarm security zones during midnight trips to the washroom.

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Hackaday Links: August 21, 2016

August 21, 2016 by 32 Comments

Are you in New York? What are you doing this week? Hackaday is having a party on Wednesday evening. come on out!

How about a pub in Cambridge? Hackaday and Tindie will be there too, on Wednesday evening. It’s a bring-a-hack, so bring a hack and enjoy the company of your fellow nerds. If this goes late enough we can have a trans-Atlantic Hackaday meetup.

Portable emulation machines are all the rage, and [Pierre] built one based on the Raspberry Pi Zero. It’s small, looks surprisingly comfortable to hold, and is apparently it’s fairly inexpensive to build your own.

For the last year or so, the Raspberry Pi Zero has existed. This came as a surprise to many who couldn’t buy a Raspberry Pi Zero. In other news, Ferraris don’t exist, and neither do Faberge egg omelets. Now, the Raspberry Pi shortage is officially over. They’re in stock everywhere, and we can finally stop listening to people who call the Pi Zero a marketing ploy.

No Starch Press is having another Humble Bundle. Pay what you want, and you get some coding books. They have Python, Haskell, and R, because no one should ever have to use SPSS.

[Reg] wrote in to tell us about something interesting he found while cruising eBay. The used and surplus market is awash in Siemens MC45/MC46 cellular modem modules. They’re a complete GSM ‘cellular modem engine’, with an AT command set, and cost about $10 each. Interfacing them with a board requires only two (strange) connectors, SIM and SD card sockets, and a few traces to through-hole pads. Anyone up for a challenge? A breakout board for this cellular modem could be very useful, should someone find a box full of these modules in a surplus shop.

On this page, about halfway down the page, is an LCD driver board. It turns a video signal into something a small, VGA resolution LCD will understand. This driver board is unique because it is completely hand-made. This is one of those small miracles of a soldering iron and copper clad board. If anyone out there is able to recognize these parts, I’d love for you to attempt an explanation in the comments.

A few weeks ago, the RTL8710 WiFi module showed up on the usual online marketplaces. Initially, we thought it was a competitor to the ever-popular ESP8266, offering a small microcontroller, WiFi, and a bunch of useful output pins. A module based on the RTL8710, the RTL-00, is much more than a competitor. It’s pinout compatible with the ESP8266. This module can be swapped into a project in place of the ESP-12, probably the most popular version of the ESP8266. This is genius, and opens the door to a lot of experimentation with the RTL8710.