Thursday, 31 December 2015

Magic Mirror on the Wall, “Is Pi or ESP, Fairest of All?”

“What’s the weather like, honey?” “I don’t know. Let me check the mirror.”  The mirror?

Both [Dylan Pierce] and [Dani Eichorn] have mirror projects that display the weather. They took two different approaches which makes for an interesting comparison. [Dylan] uses a Rapsberry Pi with an actual monitor behind the mirror. [Dani] puts an OLED behind the mirror driven by a ESP8266.  It appears there is more than one way to hack a mirror, or anything, which is what makes hacking fun.

Raspberry Pi Booting Framing Mirror and Monitor

[Dani] started with a picture frame, adding tinting film to the glass so it would reflect. A small section of tint was removed to allow the OLED to be seen. The ESP8266 software connects to the Weather Underground to get the latest information.

The Raspberry Pi version by [Dylan] puts a 27″ monitor behind the mirror. That is either terribly impressive or way over the top but seeing Linux boot behind the mirror makes it worth the effort. The Pi generates a web page which makes this adaptable as a general purpose kiosk.

A video of [Dani’s] mirror in operation, after the break.


Filed under: misc hacks, Raspberry Pi, software hacks

from Hackaday » raspberry pi
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Yet Another Pi Zero USB Hub

The Raspberry Pi Zero was back in stock at Adafruit this week – for about eight minutes. That means a few more people get Pi Zeros, many more will put them up on eBay, and everyone is working on their own version of a Pi Zero USB hub. The latest version of a Pi Zero hub comes from [Nate], and he’s doing this one right. His Pi USB adapter adds four USB ports and features not found in other DIY USB hubs like fuses and ESD protection.

As with other Pi Zero USB hub add-ons, this build relies on a USB hub controller, a few passives, and not much else. The chip used in this hub is the FE1.1s chip, a highly integrated 4-port hub controller that can be found through the usual Chinese resellers. This hub controller doesn’t require much, just a 12MHz crystal, a few passives, and four USB jacks.

Of particular interest is how [Nate] is connecting this hub to the Pi Zero. He’s left the option open for using either a USB cable, or soldering the USB’s differential pairs directly between the Pi and the hub. In either case, the hub should work, and with the addition of the zeners, fuses, and other parts that keep the hub from frying itself, [Nate] might have a very nice project on his hands.

Filed under: Raspberry Pi

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Sunday, 27 December 2015

Turning The Pi Zero Into A USB Gadget

The Raspberry Pi Zero is limited, or so everyone says, and everyone is trying to cram a USB hub and WiFi adapter on this tiny, tiny board. One thing a lot of people haven’t realized is that the Raspberry Pi Zero comes with a USB OTG port, meaning it can function as a USB device rather than a USB host. This means the Raspi can become a serial device with just a USB cable, an Ethernet device, MIDI device, camera, or just about anything else you can plug into a USB port. Adafruit has your back with a tutorial for using the USB OTG port as a serial and Ethernet interface, and the possible applications are extremely interesting.

The only requirement for using the USB OTG port for device applications is an update to the kernel. This is easily installed by dumping a few files on an SD card and a employing bit of command line wizardry. The simplest example is setting up the Pi Zero as a USB serial device, allowing anyone to log into a serial console on the Pi with just a USB cable.

A slightly more interesting application is setting up the Pi as an Ethernet gadget. This effectively tunnels all the networking on the Pi Zero through a USB cable and a separate computer. The instructions are extremely OS-specific, but the end result is the same: you can apt-get on a Pi Zero to your heart’s desire with a new kernel loaded onto the SD card and a USB cable.

This experimentation is just scratching the surface of what is possible with the OTG port on the Pi Zero. MIDI devices are easy, and with a ton of GPIOs, the Pi Zero itself could become a very interesting musical instrument. Want the Pi Zero to be a storage device? That’s easy too. The USB Gadget will end up being one of the most exciting uses for the Pi Zero, and we can’t wait to see what everyone will come up with next.

Filed under: Raspberry Pi

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Saturday, 26 December 2015

Let Alexa Control Your Life; Guide to Voice-Enable Everything

Let’s face it, automation doesn’t feel quite as futuristic unless you can just say what you want out loud and have the machines flawlessly obey. That is totally possible now — and on the cheap. Well, cheap as far as money goes. It can be an expensive learning curve to get it all working. This will help. [Lindo St. Angel] has put together a guide to navigate voice control of hardware using Amazon’s Alexa SDK.

We previously reported that Amazon’s AI had escaped its hardware prison in the form of the Alexa Skills Kit. Yes, calling it the Alexa SDK above is wrong it’s actually the ASK but nobody knows what that acronym is while most recognize the gist of an SDK. It gives you the hooks and the documentation necessary to leverage the functionality in your own applications. The core functionality of Alexa is voice recognition. Even so, it’s still a tall hill to climb.

[Lindo] has broken down the problem into a very manageable example. The Amazon Voice Service (part of ASK) is used for voice recognition and control. Amazon’s Lambda service connects the ASK to your piece of hardware; in this case he’s using a Raspberry Pi as the server. The final step is to connect your hardware to the Pi. [Lindo] is interfacing a keypad-based home automation system with the Pi but the sky’s the limit at this point.

With all the authentication and connectivity laid bare, this is a lot more approachable. The question is no longer can you connect everything to voice control. The question becomes should you give control of everything over to one single online service?

Filed under: home hacks, internet hacks

from Hackaday » raspberry pi
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Friday, 25 December 2015

Here Comes Santa Claws

Liberty Games in the UK was looking for a fun way to support charity for the holidays, and we think they succeeded. They decided to set up an arcade crane machine to run over the internet, with each type of toy snagged earning  a donation. Snag a bear, and they will donate £5 to St Mungos, a UK charity that works with homeless or at risk people. Snag one of the rarer Santa toys, and they will donate £20. It’s a great cause, and a nice hack. Behind the scenes, the Internet side of things runs on a Raspberry Pi connected to a PiRack and a couple of PiFace digital interface cards that are wired into the electronics of the crane machine so they could control the buttons on the machine from a Web interface. Unfortunately, it didn’t seem to be running when we tried it, but hopefully someone will give the machine a swift kick shortly to get it going until the Hackaday traffic invariably brings it down again.

One of the interesting thing that they discovered while working on these hacks: they have a pay-out ratio that is determined by the strength of the grabbing arm. The owner can tweak this so that the arm does not grab very firmly, which means a dropped bear. Want to torture your friends with hopes of snagging the best stuffed animals?. Follow the example of this claw machine build all from parts on hand.

Filed under: Holiday Hacks, Raspberry Pi

from Hackaday » raspberry pi
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POV Globe Display Spins up Full Color Tupac

Persistence of vision projects were once all the rage, judging by a quick review of the literature here on Hackaday. They’ve tapered off a bit lately, but this impressive full-color globe display might just kick-start some new POV projects.

Built as a final project for an EE course, [Evan] and [Kyle]’s project is more about the control electronics and programming than the mechanical end of the build. Still, spinning a 12″ ring of 1/4″ thick acrylic with a strip of APA102 LEDs glued to the edge takes some thoughtful engineering. While the build appears sturdy, [Evan] does admit to a bit of wobble under full steam, which was addressed by adding some weight to the rig. We wonder if mounting half the LEDs on each side of the ring to balance the forces wouldn’t have worked better. True, it would have complicated the coding for the display, but maybe that would have been good for extra points. In any case, the display turned out well and the quality of the images is great. And as an aside: how awesome is it that we live at a time when you can order a six-circuit slip-ring for a project like this for less than $20?

It’s the end of the semester and we love seeing the final projects that have just made it across the finish line. This globe is one, yesterday we saw a voice-controlled digital eye exam, and if you have or know of a final project, don’t forget send us the link!

If POV globes are your thing, be sure to set the Hackaday WABAC machine a few years and check out this Death Star design from 2012 or this globe from 2010.

Filed under: led hacks, misc hacks

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Tuesday, 22 December 2015

Raspberry Pi Laser Beam Profiler

[Anthony] at UCLA needed to verify the shape of a laser beam. Commercial units for this, as you would expect, are expensive. But a Raspberry Pi with a Pi Noir camera easily handles the task. Not only is the use of the Pi cool but so is the task – they are using lasers to cool molecules to study quantum effects. The Pi camera without the IR filter captures a wide bandwidth making it suitable for use with non-visible lasers. [Anthony] captures the beam along two axes and plots both curves on the LCD touchscreen. That data, based on the pictures, is also available on a host PC. All this in a super compact package with a 7″ touch screen display.

7" Raspberry Pi Touch Display showing laser beam 2D crystal of Yb ions.

One reason I find this fascinating is I did something similar 1977 at the University of Rochester Laboratory for Laser Energetics. My project was measuring the energy cross-section of a laser beam. The research goal of the Laboratory was the study of inertial confinement laser fusion. While [Anthony] uses an entire camera my project was limited to a 1 dimensional array of charge coupled devices (CCD). The output went to a Tektronix storage terminal and was printed on thermal paper for reference. He uses Python running on the target system. My work used a Z80 development system the size of a tower PC to write my program in assembly language which was then executed on a single board computer. We’ve come a long way. My code is long gone but you can get [Anthony’s] on GitHub.

Filed under: Raspberry Pi, software hacks

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Friday, 18 December 2015

Open Sesame Raspberry Pi Style

[Don] installed an Android tablet into his wife’s vehicle and realized he wanted to allow it to operate and monitor the garage door. His biggest challenge? Meeting the (what he refers to) as the WAF or Wife Acceptance Factor. He decided to use a Web app on a Raspberry Pi, along with a handful of switches and a relay. His list of goals were straightforward:

  • Provide the status of the door (open/closed/unknown)
  • Open and close the door
  • Work across multiple platforms
  • Secure enough to connect to the Internet
  • Reliable and simple

The Pi uses two switches to determine the position of the door and relay to trigger the existing garage door opener’s operation button. This simple circuit could serve many different purposes, not just opening a garage door. It would be easy to replicate the relay driver, too, if you needed more than one switch for some other purpose.

animationThe Web app is available on GitHub. There’s a cool SVG animation (see left) that shows the status of the door as it opens and closes–presumably to help get the WAF higher. This would be a great starter project for someone getting their feet wet with the Pi or with Web apps. We saw a lot of garage door openers earlier this year, including one for a cat. Still, we liked the simplicity of this one and the mesmerizing animation.

Filed under: Raspberry Pi

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Thursday, 17 December 2015

£5,400 worth of PostgreSQL training to be won


We’ve teamed up with 2ndQuadrant to give away up to £5,400 worth of training to two lucky winners who’ll be able to master their understanding and use of PostgreSQL. The global experts in PostgreSQL support, training, development, migration and consultancy are offering two £2,700 training vouchers that can be used on their approved courses in London, which 100 per cent of clients have described as “excellent.”

All 2ndQuadrant training courses are taught by leading PostgreSQL experts, with many years of industry experience in databases and code development.  Courses last between one and five days, and those currently available include Linux for PostreSQL DBAs, Replication and Recovery, and PostgreSQL Immersion – a five-day intensive course for those wanting to learn PostgreSQL fast. For more information, check out the course catalogue.

The UK Met Office approved PostgreSQL as its preferred RDBMS, following an evaluation of alternatives. The decision was influenced by 2ndQuadrant training. Data Services Portfolio Technical Lead James Tomkins commented: “With the training we had from 2ndQuadrant we could feel the weight of expertise that came with Gianni [Dr Gianni Ciolli, tutor] and it was obvious he really knew his subject inside-out. It was an enormous confidence-building exercise and has been consistent with all of our interactions with 2ndQuadrant.”

2ndQuadrant offers unrivalled access to one of the largest teams of PostgreSQL experts in the world, and continues to make significant contributions to the wider user community through development. Consequently, the company is able to offer 15-minute response times to customers in need of support.

For more information on 2ndQuadrant, you can sign up to their newsletter. Just go to and scroll to the bottom to find a sign-up form.

How to enter

To enter the competition, you just need to answer the following question:

Where was Postgres, the forerunner to PostgreSQL, first developed?

a) Massachusetts Institute of Technology
b) University of California, Berkeley
c) Harvard University

Please email your answer, along with your full name and contact details, to

Terms and conditions:

The two winners will each receive a 2ndQuadrant training voucher worth up to £2,700. A training voucher entitles the winner to book only one course, lasting up to five days and up to the value of £2,700, and cannot be used in conjunction with any other offer or discount. The training voucher will retain its value in terms of course days if prices increase before a course is booked. Winners must book a scheduled course by 1 July 2016. Courses are subject to availability and will take place in London. Course dates are subject to change. Competition entrants must be at least 18 years old. The closing date for entries is 29 February 2016. Terms and conditions are subject to change.

from Linux User & Developer – the Linux and FOSS mag for a GNU generation

Wednesday, 16 December 2015

Better Networking With A Macintosh Classic

While it may not be the case anymore, if you compare a Mac and a PC from 1990, the Mac comes out far ahead. PCs suffered with DOS, while the Mac enjoyed real, non-bitmapped fonts. Where a Windows PC required LANMAN to connect to a network, the Mac had networking built right into every single machine. In fact, any Mac from The Old Days can use this built-in networking to connect to the Internet, but most old Mac networking hacks have relied on PPP or other network to serial conversion. [Pierre] thought there was an incomplete understanding in getting old Macs up on the Internet and decided to connect a Mac Classic to the Internet with Apple’s built-in networking.

Since the very first Macintosh, Apple included a simple networking protocol that allowed users to share hard drives, folders, and printers over a local network. This networking setup was called LocalTalk. It wasn’t meant for internets or very large networks; the connection between computers was basically daisy chained serial cables and later RJ-11 (telephone) cables.

LocalTalk stuck around for a long time, and even now if you need to do anything with a Mac made in the last century, it’s your best bet for file transfer. Because of LocalTalk’s longevity, routers and LocalTalk to Ethernet adapters can be found fairly easily. The only problem is finding a modern device that speaks both TCP/IP and LocalTalk. You can’t use a new Mac for this; LocalTalk has been gone from OS X since Snow Leopard. You can do it with a Raspberry Pi, though.

With a little bit of futzing about with MacTCP and a few other pieces of software from 1993 or thereabouts, [Pierre] can even get his old Mac Classic online. Of course the browsers are all horribly outdated (making the Hackaday retro edition very useful), but [Pierre] was able to load up It takes a while with an 8MHz CPU and 4MB of RAM, but it does get the job done.

You can check out [Pierre]’s demo video below.

Filed under: classic hacks, macs hacks

from Hackaday » raspberry pi
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Tuesday, 15 December 2015

[SFTP] Connection failed : kex error : no match for method mac algo client->server: server [,,,hmac-sha2-512,hmac-sha2-256,hmac-ripemd160], client [hmac-sha1]




[SFTP] Connection failed : kex error : no match for method mac algo client->server: server [,,,hmac-sha2-512,hmac-sha2-256,hmac-ripemd160], client [hmac-sha1]

Use the 0.26.4 release,

download and copy the NppFTP.dll in to C:\Program Files (x86)\Notepad++\plugins

reload and boom

Sunday, 13 December 2015

Maker Barn Organizer Creates Makerspace Access Control System

The MakerBarn is a new makerspace between The Woodlands and Tomball, TX (north of Houston). [George Carlson], one of the founders and a retired design engineer, wanted to make sure only members certified on a machine could use it. He worked with [Kolja Windeler] to create the MACS or Makerspace Access Control System. He has one video explaining MACS and, after the break, another explaining the browser based user interface for the system.

20151205_181615A control box, [George] calls them stations, controls the power to a machine. Member badges have an RFID tag that is read when inserted into the station’s reader. If the member is authorized to use the machine, the power is enabled. For safety, the member’s badge must remain in the reader to maintain power. The reader uses a Photon board from Particle with a WiFi link to a Raspberry Pi server.

[Kolja] developed a Pi system to maintain a database of member numbers and the machines they can use. The list is sent to the stations periodically or when updates occur. The user interface is browser based on the MakerBarn’s LAN so it can be maintained by a computer or smartphone in the space. Presently 21 MACS modules have been built with some going to Hanover University in Germany for their auto hobby shop.

Not only did [George] lead the effort on creating MACS but has been key to getting the construction done inside a pole barn to make the MakerBarn a reality.

Filed under: Hackerspaces, hardware, Raspberry Pi, tool hacks

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Turning a Pi Into a PDP

There’s no better way to learn how to program a computer than assembly, and there’s no better way to do assembly than with a bunch of blinkenlights and switches. Therefore, the best way to learn programming is with a PDP-11. It’s a shame these machines are locked up in museums and the garages of very cool people, but you can build your own PDP-11 with a Raspberry Pi and just a few extra components.

[jonatron] built his own simulated version of the PDP-11 with a lot of LEDs, a ton of switches, and a few 16-bit serial to parallel ICs. Of course the coolest part of any blinkenlight simulator are the front panel graphics, and here [jonatron] didn’t skimp. He put those switches and LEDs on a piece of laser cut acrylic with a handsome PDP11 decal. The software comes with a load of compiler warnings and doesn’t run anything except for very simple machine code programs. That’s really all you can do with a bunch of toggle switches and lights, though.

If this project looks familiar, your memory does not deceive you. The PiDP-8/I was an entry in this year’s Hackaday Prize and ended up being one of the top projects in the Best Product category. We ran into [Oscar], the creator of the PiDP-8, a few times this year. The most recent was at the Hackaday SuperConferece where he gave a talk. He’s currently working on a replica of the king of PDPs, the PDP-11/70.

Video below.

Filed under: classic hacks

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Raspberry Pi Communication Via LASER

[Nick Touran] wanted to make two Raspberry Pi’s communicate wirelessly. There are lots of options, but [Nick] used a LASER and a photoresistor, along with Morse code. If you don’t find Morse code fancy enough, you could always refer to it as OOK (on/off keying). The circuit uses a common LASER module and an ordinary photoresistor that varies in resistance based on light. A resistor forms a voltage divider with the photoresistor and an external A/D reads the resulting voltage.

The circuit works, but we couldn’t help but notice a few items. Not all photoresistors are as sensitive to the same light wavelengths, so for the maximum range you’d want to pick a particular photoresistor.  While the analog to digital converter is certainly workable, we couldn’t help but wonder if you couldn’t set up the divider to use the inherent threshold of the Raspberry Pi’s input pins for a simpler circuit. Of course, if you used the same technique with an Arduino, you could use the built-in A/D converter, and the A/D converter is probably easier to get working.

The prototype only uses one Pi that talks to itself, but if you had two, they could talk to each other using this scheme. The software uses some previous code [Nick] wrote to generate the code and looks to be easy to work with and modify.

Communicating with light isn’t a new idea. Bell had the Photophone, and we’ve covered LASER communications before. And just yesterday we ran a post on LiFi, which attempts to replace WiFi with light.

Filed under: laser hacks, Raspberry Pi

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Friday, 11 December 2015

Which SD Card to Use in a Pi?

There is surprising variation in the performance of SD cards. They are not all created equal and the differences can impact the running of your Raspberry Pi, no matter which model. [Jeff Geerling] wondered exactly how different cards would affect system performance. He ran a number of tests on cards ranging from cheap no-names to well-known brand names. The no-name cards fared pretty badly but even among the brand names there is considerable variation.


[Matt] over at Raspberry Pi Spy also tested SD cards and found similar differences. Both tested microSD cards. [Jeff’s] tests were solely on the Pi while [Matt’s] were on Windows 7, Ubuntu, and a Pi.

The discussions in the blog about what to measure were as interesting as the actual results. That lead to determining which software tools to use for the measurement. For example, a system doing a lot of small database reads and writes might work better with one SD card while a system storing and then streaming videos might work better with another card. Another interesting result is that the Pi’s data bus greatly limits the access speeds. [Jeff] measured much higher speeds running the same tests using a Mac with a USB dongle. The cards are capable of much more than the Pi can deliver.

[Matt] also checked the capacity of the SD cards. There are a lot of fakes floating around marked with higher capacities than they actually support. Even getting a brand name card may not help since some are counterfeit. So beware: if the price it too good to be true, it very well may be.



Filed under: parts, Raspberry Pi

from Hackaday » raspberry pi
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Thursday, 10 December 2015

Pick up the new Linux & Open Source Genius Guide now!

The essential guide to mastering open source software and operating systems

Linux and other open source software packages can give you an exhilarating sense of freedom in making your computer your own, no matter what you use it for. In this Genius Guide, you’ll learn advanced tips for how to get the most out of the latest distros, and find projects to try out. We take a look at the best distros and software of the year so far, and show you how to get faster, better servers now.

001_LLG_007R_Eshop 025_LLG_007R 153_LLG_007R

You can get your copy now from the best newsagents, supermarkets and, as ever, the Imagine Shop


from Linux User & Developer – the Linux and FOSS mag for a GNU generation

Wednesday, 9 December 2015

Raspberry Pi $2 WiFi Through Epic SDIO Hack

These are the times that we live in: the Raspberry Pi Zero comes out — a full freaking Linux computer on a chip for $5 — and people complain that it doesn’t have this or that. Top place on the list of desiderata is probably a tie between audio out and WiFi connectivity. USB is a solution for both of these, but with one USB port it’s going to be a scarce commodity, so any help is welcome. hacker [ajlitt] is looking for a way out of the WiFi bind. His solution? The Raspberry Pi series of chips has a special function on a bunch of the GPIO pins that make it easier to talk to SDIO devices. SDIO is an extension of the SPI-like protocol that’s used with SD memory cards. The idea with SDIO was that you could plug a GPS or something into your PDA’s SD card slot. We don’t have PDAs anymore, but the SDIO spec remains.

[ajlitt] dug up an SDIO driver for the ESP8089 chip, and found that you can liberate the ESP8266’s SPI bus by removing a flash memory chip that’s taking up the SPI lines. Connect the SPI lines on the ESP8266 to the SDIO lines on the Raspberry Pi, and the rest is taken care of by the drivers. “The rest”, by the way, includes bringing the ESP’s processor up, dumping new firmware into it over the SPI/SDIO lines to convince it to act as an SDIO WiFi adapter, and all the rest of the hardware communication stuff that drivers do.

The result is WiFi connectivity without USB, requiring only some reasonably fine-pitch soldering, and unlike this hack you don’t have to worry about USB bus contention. So now you can add a $2 WiFi board to you $5 computer and you’ve still got the USB free. It’s not as fast as a dedicated WiFi dongle, but it gets the job done. Take that, Hackaday’s own [Rud Merriam]!

Thanks [J0z0r] for the tip!

Filed under: Raspberry Pi, wireless hacks

from Hackaday » raspberry pi
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Monday, 7 December 2015

Hackaday Links: December 6, 2015

[Camus] had it all wrong. After a few hundred years of rolling a stone up a mountain, Sisyphus would do what all humans would do: become engrossed in novelty. The stone would never reach the summit, but it could roll off some pretty sweet ramps. That mountain goat that ticked him off a few decades ago? If Sisyphus let go right now, the stone would probably take that goat out. Sisyphus, like all of us, would be consumed in meaningless novelty. One must imagine Sisyphus happy.

The pumpkin spice must flow. It’s the holidays and for a lot of us that means copious amounts of baked goods. How about an edible sandworm? It looks like something close to a cinnamon roll.

This December’s Marie Claire – whatever that is, I have no idea – features haute circuits. These circuit boards are the work of [Saar Drimer] and Boldport, makers of fine circuit board art. We’ve seen his work a number of times featuring squiggly traces and backlit panels. This seems to be the first time Boldport and the entire idea of PCB art has infiltrated the design world. He also does puzzles.

Raspberry Pi cases simply do not look cool. There’s ports coming out everywhere, and plastic really doesn’t look that great. You know what does look great? Walnut. [Karl] made a few of these out of walnut, MDF and solid aluminum. He’s thinking he might bring this to market, you can check out his webzone here.

Self-driving cars being sold right now! That’s an eBay link for a DARPA Grand Challenge vehicle, a heavily modified Isuzu VehiCross loaded up with computers, a laser scanner, camera, and connected to actuators for steering, brake, pedals, and shifter.

A few years ago, a snowboarding company realized they could use YouTube as a marketing device. They made some really cool projects, like a snowboard with battery-powered heaters embedded in the core of the board (yes, it works). There’s only so many different snowboards you can build, so they turned to surfboards. In fact, they turned to cardboard surfboards, and last week they made a cardboard electric guitar in the Fender custom shop. It’s a completely understandable linear progression from A to B to I don’t know what kind of glue they’re using.

Filed under: Hackaday Columns, Hackaday links

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Sunday, 6 December 2015

Wireless Water Meter Monitor Watches Waste

It’s no secret that hackers like to measure things. Good numbers lead to good decisions, like when to kick your wastrel teenager out of a luxuriously lengthy shower. Hence the creation of this wireless Arduino-based water meter interface.

We’ll stipulate that “wireless” is a bit of a stretch. Creator [David Schneider] chose to split the system into two parts – a magnetometer and an Arduino to sense impulses from the water company meter, and a Raspberry Pi to serve the web interface. The water meter is at the street rather than in his house, so the sensor is wired to the Pi with some telephone cable. But from there the system is wireless.

[David] goes into some good detail on the sensing problem he faced, which relies on detecting the varying magnetic field due to the spinny-bits inside the flowmeter and cleaning up the signal with the Arduino; he also addresses aliasing errors that occur when flow rate approaches the sampling rate of the magnetometer.

We like the fact that there’s a lot of potential to leverage this technique to monitor other processes with rotating magnetic fields. And like this optically coupled gas-meter monitor, it’s not invasive of the utility’s equipment either, which is a plus.

[via reddit]

Filed under: green hacks, home hacks

from Hackaday » raspberry pi
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A Sound and LED-tastic Tricycle Shopping Cart

What do you get when you take a massive number of LEDs and combine them with a shopping cart and a bicycle? An awesome rave-mobile created by [kramerr]. He’s even taking it one step further by making the electronics solar powered.

[Kramerr] controls the LEDs with multiple WS2803 LED drivers. Three PIC18F4550s control the WS2803s over SPI. He devised a neat way of exciting the LEDs from music by using a pair of graphic equalizer display filter chips, MSGEQ7s, to drive the PICs to create patterns. A USB input also allows the PICs to display song titles or other information.

leds and boards

The mechanical design is as impressive as the electronics. The rear half of a bicycle is welded to the frame of the shopping cart with the cart’s handle used for steering. The shopping cart’s rear wheels are replaced by small bicycle wheels.

But [Kramerr] wasn’t done. He built his own solar panel since he couldn’t find one to fit the size requirements. The panel consists of 26 cells connected in series to provide 1A at 13V on a sunny day. A solar charge controller keeps a standard 12v lead acid battery ready to power the tricycle cart.

And there is still more! There is a sound system driven by a Raspberry Pi. The Pi also drives the USB inputs when [Krameer] wants to display song titles or artists instead of the audio patterns.

There are at least four hacks in this project each worthy of applause. [Karmeer] deserves an ovation for doing all of them in one project. If you are looking for less bling and less pedaling may we direct you to this powered, riding shopping cart.

Some rave music and lights via video after the break.

Filed under: digital audio hacks, led hacks, musical hacks, Raspberry Pi

from Hackaday » raspberry pi
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Friday, 4 December 2015

3 Nerds + 2 Days = Little Big Pixel

Two days at a company sponsored hackathon? Sounds like fun to us! And productive too – the end result for [GuuzG] and two of his workmates from their company’s annual “w00tcamp” was this festive and versatile 16×16 pixel mega display.

From the sound of it, [GuuzG] and his mates at are not exactly hardware types, but they came up with a nice build nonetheless. Their design was based on 16 WS2812 LED strips for a 256 pixel display. An MDF frame was whipped up with cross-lap joints to form a square cell for each pixel. Painted white and topped with a frosted Plexiglass sheet, each RGB pixel has a soft, diffuse glow yet sharply defined borders. Powered by a pair of 5A DIN rail DC supplies and controlled by a Raspberry Pi, the finished display is very versatile – users can draw random pixel art, play the Game of Life, or just upload an image. [GuuzG] and company are planning to add Tetris, naturally, and maybe a webcam for fun.

We’ve seen lots of uses for the ubiquitous WS2812 LEDs, from clocks to Ambilight clones to ground-effect lighting for an electric skateboard. But if you’re in the mood for a display that doesn’t use LEDs, there’s always this multithreading display.

[via Reddit]

Filed under: misc hacks, Raspberry Pi

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Thursday, 3 December 2015

Shoving a Raspberry Pi Zero Into an Xbox Controller

With the release of the Raspberry Pi Zero last month, we’ve been waiting in excitement to see the first creative hacks to come out, making use of its tiny size; which if you didn’t know, is smaller than a business card. [Terence Eden] hopped to it and made what might be the first Raspberry Pi Zero emulator: inside an Xbox controller.

10-Pi-Cardboard-insulatorThanks to its small size it’s actually a fairly straight forward hack with minimal modification to the controller in order to make it fit. In fact, you only need to remove the memory card holder from the controller and snip one bit of plastic in order to make it fit right in the middle — awesome.

Now it does stick out a bit as you can see in the pictures, but we’re sure it won’t take someone long to make a 3D printed part that snaps into the controller giving it a more stock appearance. Unfortunately since HDMI can’t carry a power source to the Pi, [Terence] is using a micro-USB to power it — but there is enough space inside the controller for a battery pack if you wanted to make it truly portable.

On the software side, he’s using a pre-built image of RetroPie which means you pretty much just need to load it and go. Is it just us or is the Raspberry Pi foundation working? Super accessible and easy to use computing for all!

PS: In case you’ve been living under a rock and still don’t know what the Pi Zero is, you can check out our original coverage of the device here, and a more thorough history and explanation of it here.

[Thanks Max!]

Filed under: Raspberry Pi, xbox hacks

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Tuesday, 1 December 2015

Listening to the Sounds of the Earth

A geophone is a specially built microphone for listening to the Earth. [JTAdams] found them at a reasonable price so bought some to play with. A geophone is used to detect vibrations from earthquakes, explosions, rumbling trucks, and vibroseis vehicles. To be useful it needs an amplifier and a recording device to capture the signals.


[JTAdams] used a standard amplifier design for an LT1677 op-amp, fed the signal to an MCP3008 A/D converter, and read the output using a Raspberry Pi. A Python script records the data to a CSV file for processing. The Pi worked well because the entire setup needs to be portable to take into the field. Another Python script plots the data which is made available from a web page. A neat simple way of presenting the raw data. [JTAdams] promises more information in the future on post-processing the data. You don’t need a geophone to detect seismic waves if you build your own, but a real ‘phone will be more rugged.

Oh, what’s a vibroseis? It’s a truck with a big flat plate underneath it. The plate is hydraulically lowered to the ground until the weight of the truck is on it. The truck then causes the plate to vibrate, usually sweeping from around 10 hz to 100 hz. This infrasound pass through the ground until it is reflected back by underlying rock layers. A long string of geophones, think 1,000s of feet, detects the waves, which are recorded. In practice, many trucks are used to generate a synchronized signal of sufficient strength. Or, you can set off an explosion which is the technique used in water. Typically the information is used for oil and gas exploration.  A video of one of the trucks in action after the break.

Filed under: misc hacks, Raspberry Pi

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