Code Craft: Cross Compiling For The Raspberry Pi

February 3, 2016 by Rud Merriam 48 Comments

Sometimes there’s just no place like your desktop. You’ve already got your favorite development tools and references setup or installed and it’s a pain when you’re trying to work on an unfamiliar, or simply uncustomized, system. On your desktop everything is at your fingertips. If you want to search the web, the browser is just an alt-tab away. If you need a calculator, it’s right there to run. Your editor highlights syntax in your favorite colors already.

When developing on a Raspberry Pi, you leave all these creature comforts behind unless you spend the time to configure the Pi to your liking. Then it all gets wiped when you install a new distribution, like the recent change from Wheezy to Jessie. Even then it’s frustrating to switch back and forth between the desktop and the Pi because there is always something on the other system that you need. My usual comment is, “dirty word”, literally.

Cross-developing on your desktop is a very workable solution. We’re going to walk through setting up your desktop and a Pi to do this. This means loading a Pi ARM toolchain on your desktop and a debugging server on the Pi. This’ll let you develop and debug from in the comfort of your desktop. An added advantage is when you put that Pi in a robot you can debug over a wireless link.

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Cramming A Pi Zero Into A USB Hub

February 1, 2016 by James Hobson 41 Comments

We kinda feel bad posting all these awesome hacks you can do with a Raspberry Pi Zero when we know most of our audience here probably doesn’t have one due to the backlog of orders… but regardless — here’s another one you can try — if you have one anyway. A Raspberry Pi USB Hub!

In case you didn’t know, Amazon has a series of electronics accessories called Amazon Basics — and they’re actually pretty good quality accessories. One of them is a 7-port, 4A USB hub. Looking at this [gittenlucky] figured he might just have enough room to fit a Pi Zero inside… and as it turns out. He did.

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Fingerprint Scanner For Laptop And Raspberry Pi (or Giving The Finger To Your Computer)

January 29, 2016 by Rud Merriam 28 Comments

We’ve got two hacks in one from [Serge Rabyking] on fingerprint scanning. Just before leaving on a trip he bought a laptop on the cheap. He didn’t pay much attention to the features and was disappointed it didn’t have a fingerprint scanner. Working in Linux he uses sudo a lot and typing the password is a hassle. Previously he just swiped his finger on the scanner and execution continued.

He found a cheap replacement fingerprint scanner on hacker’s heaven, also known as eBay. It had four wires attached to a 16 pin connector. Investigation on the scanner end showed the outer pair were power and ground which made [Serge] suspect it was a USB device. Wiring up a USB connector and trying it the device was recognized but with a lot of errors. He swapped the signal lines and everything was perfect. He had sudo at his finger tip.

Next he wonder if it would work with a Raspberry Pi. He installed the necessary fingerprint scanning software, ran the enrollment for a finger, and it, not terribly surprisingly, worked.

On Linux the command fprintd-enroll reads and stores the fingerprint information. By default it scans and saves the right index finger but all ten fingers can be scanned and stored. Use libpam-fprintd to enable account login using a finger. Anyone know how you can trigger other events using a different finger? A quick search didn’t turn up any results.

In true hacker style, [Serge] created his own fingerprint reader from a replacement part. But you can jump start your finger usage by purchasing one of many inexpensive available readers.

Turning A Lapdock Into A Laptop With The Pi Zero

January 26, 2016 by James Hobson 25 Comments

Do you remember the Motorola Lapdock 100? It was a CPU-less laptop designed for plugging in your smartphone that enabled you to use your phone as a computer! Perhaps a bit ahead of its time, they never really caught on — but now you can buy them pretty cheap, and with the release of the Raspberry Pi Zero, it was only a matter of time before someone combined the two.

The Lapdock 100 has long been a useful accessory for the Raspberry Pi, but until the Zero came out, it was always a messy bundle of wires running to and from the devices, making it a less than ideal solution. The Zero changes everything. [Ax0n] knew he had to try combining the two.

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Raspberry Pi Zero Cluster Packs A Punch

January 25, 2016 by James Hobson 91 Comments

If you could actually buy 16 Raspberry Pi Zeros, you might be able to build your very own Raspberry Pi Cluster for only $80! Well… minus the cost of the board to tie them all together…

A Japanese company called Idein is developing a Raspberry Pi module called the Actbulb for computational sensing and data analysis. In order to perform internal testing they decided to make things easier for themselves by developing a board to allow them to plug in not one, not two, but sixteen Raspberry Pi Zeros:

Since we will use Pi’s GPU for image processing, deep learning, etc. We need real Pis but not just Linux machines. Another reason. It can be used for flashing eMMCs of our devices via USB ports when we have to do that by ourselves.

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Cricket Scoreboard Is A Big Win For Novice Hackers

January 24, 2016 by Dan Maloney 14 Comments

The game of cricket boggles most Americans in the same way our football perplexes the rest of the world. We won’t even pretend to understand what a “wicket” or an “over” is, but apparently it’s important enough to keep track of that so an English cricket club decided to build their own electronic scoreboard for their – pitch? Field? Help us out here.

This scoreboard build was undertaken by what team member [Ian] refers to as some “middle-aged blokes from Gloucestershire” with no previous electronics experience. That’s tough enough to deal with, but add to it virtually no budget, a huge physical size for the board, exposure to the elements, and a publicly visible project where failure would be embarrassingly obvious, and this was indeed an intimidating project to even consider. Yet despite the handicaps, they came up with a great rig, with a laser-cut acrylic cover for a professional look. A Raspberry Pi runs the LED segments and allows WiFi connections from a laptop or phone in the stands. They’ve even recently upgraded to solar power for the system.

And we’ll toot our own horn here, since this build was inspired at least in part by a Hackaday post. The builders have a long list of other links that inspired or instructed them, and we think that says something powerful about the hacker community that we’ve all been building – a group with no previous experience manages a major build with the guidance of seasoned hackers. That’s something to feel good about.

Pi Zero Recipe Kiosk

January 23, 2016 by Elliot Williams 16 Comments

Why do you want to have a tiny $5 Linux system on a chip? Because you can cram it into a discarded LCD monitor and you’ve got a useful device. [zarderxio] did just that, satisfying the age-old dream of the kitchen computer with junk that was lying around in the basement.

There’s not much to this hack. The Raspberry Pi Zero needs a 5V power supply and the screen has 12V, so a step-down converter takes care of that. [zarderxio] hard-wires the monitor out of the Zero straight up to the monitor’s input jack, and hot-glues a USB hub to the outside of the monitor for a keyboard and mouse. (Because if there’s one thing we know, it’s that the Raspberry Pi Zero needs more USB ports: see exhibit A and exhibit B just for example.)

Now you’re all thinking, “USB keyboard and mouse?!?! I want a touchscreen!” Do you really? In the kitchen, with sticky fingers? Well, the screen in [zarderxio]’s junk box didn’t have a touchscreen, and this makes it more flexible, so we’re on the side of the quick hack done. Who knows, maybe he’ll hack yet another Raspberry Pi Zero into a smudge-proof recipe controller?

[via reddit.]