Testing The Outernet Dreamcatcher SDR

June 20, 2017 by Al Williams 8 Comments

What do you get when you cross an ARM-based Linux PC and an RTL-SDR? Sounds like the start of a joke, but the answer is Outernet’s Dreamcatcher. It is a single PCB with an RTL-SDR software defined radio, an L-band LNA, and an Allwinner A13 processor with 512MB of RAM and a 1 GHz clock speed. The rtl-sdr site recently posted a good review of the $99 board.

We’ll let you read the review for yourself, but the conclusion was that despite some bugs, the board was no more expensive than pulling the parts together separately. On the other hand, if you uses, for example, a Raspberry Pi 3, you might expect more support and more performance.

Despite the L-band hardware, there is a bypass antenna jack that allows you to receive other frequencies. There’s also two SD slots, one to boot from and another for storage. Several pieces of software had trouble running on the somewhat sluggish CPU, although some software that is optimized for the particular processor used fared better. You can read the details in the review.

The board is interesting, although unless you have a special packaging problem, you are probably as well off to combine a Pi and a dongle, as we have seen so many times before. If you have more horsepower you can even make the Pi transmit, although we’d suggest some filtering if you were going to do that for real.

Btrfs For The Pi

June 18, 2017 by Al Williams 19 Comments

File systems are one of those things that typical end users don’t think much about. Apparently, [seaQueue] isn’t a typical end user. He’s posted some instructions on how to run an alternate file system–btrfs–on the Raspberry Pi.

The right file system can make a big difference when it comes to performance and maintainability of any system that deals with storage. Linux, including most OSs for the Raspberry Pi, uses one of the EXT file systems. These are battle-hardened and well understood. However, there are other file systems, many of which have advanced features superior to the default file system for some applications.

Btrfs, often pronounced “butter eff ess”, begin life at Oracle and was born from an idea in an IBM paper. It offers advanced features like pooling, snapshots, and the ability to fuse multiple devices into one logical device. One notable feature the file system offers is copy-on-write. That means file copies can share common blocks as long as they stay common. Compression is available, as is seeding a file system with read-only storage, which could be very useful in some embedded systems. You can also configure several types of RAID using nothing but btrfs. You can see a video presentation about features of btrfs below.

Continue reading “Btrfs For The Pi” →

DIY Raspberry Neural Network Sees All, Recognizes Some

June 14, 2017 by Steven Dufresne 36 Comments

As a fun project I thought I’d put Google’s Inception-v3 neural network on a Raspberry Pi to see how well it does at recognizing objects first hand. It turned out to be not only fun to implement, but also the way I’d implemented it ended up making for loads of fun for everyone I showed it to, mostly folks at hackerspaces and such gatherings. And yes, some of it bordering on pornographic — cheeky hackers.

An added bonus many pointed out is that, once installed, no internet access is required. This is state-of-the-art, standalone object recognition with no big brother knowing what you’ve been up to, unlike with that nosey Alexa.

But will it lead to widespread useful AI? If a neural network can recognize every object around it, will that lead to human-like skills? Read on. Continue reading “DIY Raspberry Neural Network Sees All, Recognizes Some” →

Multifunction Raspberry Pi Chiptune Player

June 11, 2017 by Inderpreet Singh 17 Comments

General Instrument’s AY-3-8910 is a chip associated with video game music and is popular with arcade games and pinball machines. The chip tunes produced by this IC are iconic and are reminiscent of a great era for electronics. [Deater] has done an amazing job at creating a harmony between the old and new with his Raspberry Pi AY-3-8910 project.

[Deater] already showed us an earlier version of the project on a breadboard however after having made some PCBs and an enclosure the result is even more impressive. The system consists of not one but two AY-3-8910 for stereo sound that feed a MAX98306 breakout for amplification. A Raspberry Pi 2 sends six channels worth of data via 74HC595 shift registers driven by SPI. There is a surplus of displays ranging from a matrix to bar graph and even 14-segment displays. The entire PCB is recognized as a hat courtesy an EEPROM which sits alongside a DS1307 RTC breakout board. The enclosure is simple but very effective at showing the internals as well as the PCB art.

The software that [Deater] provides, extends the functionality of the project beyond the chiptunes player. There is a program to use the devices as an alarm clock, CPU meter, electronic organ and even a playable version of Tetris as seen in the demo video below. The blog post is very informative and shows progress in a chronological fashion with pictures of the design at various stages of development. [Deater] provides a full set of instructions as well as the schematic along with code posted on GitHub.

If you have a soft spot for the Arduino you may want to check out the 8-bit version of a chip tune player and if you are craving some old hardware peripheral information, do check out the computer curiosities from the Iron Curtain period. Continue reading “Multifunction Raspberry Pi Chiptune Player” →

Raspberry Pi Malware Mines BitCoin

June 8, 2017 by Al Williams 80 Comments

According to Russian security site [Dr.Web], there’s a new malware called Linux.MulDrop.14 striking Raspberry Pi computers. In a separate posting, the site examines two different Pi-based trojans including Linux.MulDrop.14. That trojan uses your Pi to mine ~~BitCoins~~ some form of cryptocurrency. The other trojan sets up a proxy server.

According to the site:

Linux Trojan that is a bash script containing a mining program, which is compressed with gzip and encrypted with base64. Once launched, the script shuts down several processes and installs libraries required for its operation. It also installs zmap and sshpass.

It changes the password of the user “pi” to “\$6\$U1Nu9qCp\$FhPuo8s5PsQlH6lwUdTwFcAUPNzmr0pWCdNJj.p6l4Mzi8S867YLmc7BspmEH95POvxPQ3PzP029yT1L3yi6K1”.

In addition, the malware searches for network machines with open port 22 and tries to log in using the default Raspberry Pi credentials to spread itself.

Embedded systems are a particularly inviting target for hackers. Sometimes it is for the value of the physical system they monitor or control. In others, it is just the compute power which can be used for denial of service attacks on others, spam, or — in the case — ~~BitCoin~~ mining. We wonder how large does your Raspberry Pi botnet needs to be to compete in the mining realm?

We hope you haven’t kept the default passwords on your Pi. In fact, we hope you’ve taken our previous advice and set up two factor authentication. You can do other things too, like change the ssh port, run fail2ban, or implement port knocking. Of course, if you use Samba to share Windows files and printers, you ought to read about that vulnerability, as well.

Self-Driving RC Cars With TensorFlow; Raspberry Pi Or MacBook Onboard

June 6, 2017 by Mike Szczys 13 Comments

You might think that you do not have what it takes to build a self-driving car, but you’re wrong. The mistake you’ve made is assuming that you’ll be controlling a two-ton death machine. Instead, you can give it a shot without the danger and on a relatively light budget. [Otavio] and [Will] got into self-driving vehicles using radio controlled (RC) cars.

[Otavio] slapped a MacBook Pro on an RC car to do the heavy lifting and called it carputer. The computer reads Hall effect sensor data from the motor to establish distance traveled (this can be used to calculate speed) and watches the stream from a webcam perched on the chassis. These two sources are fed into a neural network using TensorFlow. You train the system by driving the vehicle manually through the course a few times and then let it drive itself.

In the video interview below, you get a look at the car and [Otavio] gives commentary on how the system works as we see playback of a few races, including the Sparkfun 2016 Autonomous Vehicle Competition. I apologize for the poor audio, they lost the booth lottery and were next door to an incredibly noisy robot band (video proof) so we were basically shouting at each other. But I think you’ll agree it’s worth it to get a look at the races. Continue reading “Self-Driving RC Cars With TensorFlow; Raspberry Pi Or MacBook Onboard” →

Sun Ray Thin Client Becomes Raspberry Pi Workstation

June 5, 2017 by Jenny List 15 Comments

One of the great predictions of desktop computing from the mid 1990s was that we would all move to so-called thin clients, stripped-out desktop computers containing only processor, display driver, and peripheral interfaces, that would call up their applications not from a local hard disk but from a remote server. It was one that was never fulfilled in quite the way its proponents envisaged, but a business thin client hardware market did emerge for the likes of Citrix sharing of Windows applications. In a sense we have reached the same point through cloud-based in-browser applications such as Google Apps or Office 365, though even with newer thin client hardware such as the Chromebook these are still largely used on more traditional machines.

Even though thin clients never took the world by storm, it is still not unusual to encounter the hardware once it has outlived its usefulness. A surplus Sun Ray 270 all-in-one thin client came [Evan Allen]’s way, and to make something useful from it he converted it into a Raspberry Pi workstation.

The Sun Ray 270 has a MIPS processor board integrated into a 17 inch monitor. [Evan] was fortunate enough to find a generic HDMI controller board for its LCD panel, so was able to dispense with the MIPS board entirely and couple the controller with an automatic HDMI switch. This allows him to use the device both as a Raspberry Pi and as a monitor.

This may not rank among the most epic hacks ever, but it has delivered [Evan] a useful computer and it’s reminding the rest of us that these thin clients can be repurposed. So if one lands on your bench, look at it with fresh eyes.

Of course, if you have a Pi in a thin client, you could always take it full circle and use it to run a thin client.