Building A Raspberry Pi Rover: My Big Fat Linux Weekend

May 9, 2019 by Lewin Day 46 Comments

Linux! Such a wonderful, rich, capable operating system has blessed us, and all for the low, low cost of absolutely free. It’s under the hood of countless servers, computers, phones, and embedded devices, and is the go-to solution for when you want to get the job done right. Why, then, does it curse me so?

Prologue

The penguin giveth, and the penguin taketh away.

My experience with the almighty penguin stretches back to the late 90s. Facebook hadn’t been invented yet, so most weekends were spent installing whatever came on the front of the latest computer mags. I wish I was kidding, but I’m really not.

Way back when, us kids would load the latest Red Hat or Fedora distribution onto our hand-me-down Pentium IIs, trying not to accidentally wipe our hard drive in the process. Limited to dial-up internet and very few help resources, it was pretty common that you’d spend hours watching progress bars tick over, only to wind up with no working mouse, or an X server that simply refused to start for man or God. Did I mention we did all this for fun?

Trying To Get Some Work Done

Of course, after growing up, real life and real responsibilities take over. Now, if I’m using Linux, it’s because I’ve got a job to do, not just because there’s nothing good to watch on Cartoon Network this weekend. I consider myself to be a fairly intermediate user. I’ve compiled a few things successfully, understood how to work with a variety of package managers, and once, just once, even managed to connect to a wireless network from the command line. There’s not a whole lot that phases me in this realm anymore.

For the past few years, I’ve been slowly working on a little rover by the name of TKIRV, powered by a Raspberry Pi. It was overdue for a camera upgrade, as I’d been using an old Microsoft webcam for far too long. I ordered a nice 1080p Raspberry Pi camera, and naturally the parts marinated in their boxes for a good couple of years. Finally, after much procrastination, I was eager to get my wheely boi back out on the road.

This was but the beginning my weekend slaying embedded Linux dragons.

Continue reading “Building A Raspberry Pi Rover: My Big Fat Linux Weekend” →

Wandel Weaponizes Waste With Lego And A Raspberry Pi

May 9, 2019 by Inderpreet Singh 6 Comments

Before 3D printers, there was LEGO. And the little bricks are still useful for putting something together on the quick. Proof is YouTuber [Matthias Wandel]’s awesome bottle cap shooter build that uses rudimentary DIY computer vision to track you and then launch a barrage of plastic pieces at you.

This is an amazing project that has a bit of something for everyone. Lets start with the LEGO. [Matthias Wandel] starts with making a crossbow designed launcher and does an awesome job with showing us how it works in a video. The mechanism is an auto reloading and firing system that can be connected to a stepper motor. Next comes the pan and tilt mechanism which allows the turret to take better aim at moving targets: more LEGO and stepper motors.

The target tracker uses color matching in a program that curiously uses no OpenCV. It compares consecutive frame and then filters out red objects – the largest red dot is it. Since using a fisheye lens on the Raspbery Pi camera adds distortion, [Matthias Wandel] uses a jig made with more Legos to calibrate the image.

The final testing involved having his own child walk around the room being hunted but the autonomous machine. Kids do love toys even if they are trying to shoot bottle caps at them.

Want more Lego inspiration? Check out the Lego Quadcopter Mod and the Lego Tank with the ESP8266.

Continue reading “Wandel Weaponizes Waste With Lego And A Raspberry Pi” →

Thumbs Up For This CRT Handheld Gaming Console

May 6, 2019 by Sven Gregori 10 Comments

Despite all the progress video game graphics have made, it is safe to say that we won’t see any decline in oldschool 8-bit games any time soon. For some it’s about nostalgia, for others it’s just a great and simple-enough first step into game development itself. For [gocivici] it was a bit of both when he built this camcorder style, one-button gaming console.

With a Raspberry Pi Zero running PICO-8 at its core, [gocivici] salvaged the viewfinder of an old camcorder for the display, and that way turned it into a whole other kind of handheld console. For full ergonomic handling, one single, thumb-operated push button serves as only control option. This of course makes it a bit challenging to re-use existing games that would require more input options, so he and some friends decided to just write a suitable game on their own with the hopes that others might follow.

Unfortunately we don’t see a lot of projects using these old camcorder viewfinders, and considering modern LCD and OLED options it’s not really that surprising, but there’s just something intriguing about these tiny CRTs. So in case you want to see more of them, have a look at this tiny Atari display, and the DIY night vision monocle from a few years back. And to keep your eyes safe and sound, [gocivici] got you covered as well.

Continue reading “Thumbs Up For This CRT Handheld Gaming Console” →

Custom Monitor For Pi-Powered Commodore 64

May 3, 2019 by Rich Hawkes 2 Comments

Classic games never seem to have gone out of style and with the emulation powers of the Raspberry Pi, there seems to be no end of projects folks have been coming up with. [Chris Mills] project is a great looking monitor to get his Commodore 64 fix by combining the retro looks of a home-made 64-style monitor with the Raspberry Pi.

[Chris] is only interested in Commodore 64 emulation, at least with this project, and wanted something that would fit on a desk without taking up too much room. An eight inch LCD security monitor fit the bill perfectly. [Chris] ended up building a wooden enclosure for the monitor to give it that Commodore look. The monitor, power supply and cable connections fit inside along with speakers; each of these having their inputs on the back. A fan vents in the back as well and the Pi sits outside running the Combian 64 emulation software.

[Chris] has put up some galleries of build pics. The logo from the old Commodore logo is a nice touch. Read over the Hackaday site and you could build your own Commodore 64, or use the Commodore 64 itself to house the Raspberry Pi if you wanted.

A Raspberry Pi Is A Hardware Hacker’s Swiss Army Knife

May 2, 2019 by Bryan Cockfield 33 Comments

By now most of us have used a Raspberry Pi at some level or another. As a headless server it’s a great tool because of its price point, and as an interface to the outside world the GPIO pins are incredibly easy to access with a simple Python script. For anyone looking for guidance on using this device at a higher level, though, [Arun] recently created a how-to for using some of the Pi’s available communications protocols.

Intended to be a do-everything “poor man’s hardware hacking tool” as [Arun] claims, his instruction manual details all the ways that a Raspberry Pi can communicate with other devices using SPI and I2C, two of the most common methods of interacting with other hardware beyond simple relays. If you need to go deeper, the Pi can also be used as a full JTAG interface or SWD programmer for ARM chips. Naturally, UART serial is baked in. What more do you need?

As either a tool to keep in your toolbox for all the times you need to communicate with various pieces of hardware, or as a primer for understanding more intricate ways of using a Raspberry Pi to communicate with things like sensors or other computers, this is a great write-up. We also have more information about SPI if you’re curious as to how the protocol works.

Thanks to [Adrian] for the tip!

OpenGL Shaders And An LED Cube

April 30, 2019 by Jenny List 8 Comments

Back in February at the Hacker Hotel camp in the Netherlands, among the many pieces of work around the venue was a rather attractive LED cube. Very pretty, but LED cubes have been done many times before.

If a casual attendee had taken the time to ask though, they might have found something a little more interesting, for while the cube in question might have had the same hardware as the others it certainy didn’t have the same software. [Polyfloyd] had equipped his LED cube with OpenGL shaders to map arbitrary images to the cube’s pixels in 3D space.

Hardware-wise it’s the same collection of AliExpress LED panels and Raspberry Pi driver board that the other cubes use, in this case mounted on a custom laser-cut frame. Driver software comes from an open-source library round which he’s put a wrapper allowing input through a UNIX pipe. This can take the RGB output of an OpenGL shader, of which he has created both 2D to 3D and spherical projection versions. The must-see demo is a global map of light pollution, and the result is a rather impressive piece of work.

If LED cubes are your thing, don’t forget this recent Hackaday Prize entry.

Raspberry Pi Becomes The Encrypted Password Keeper You Need

April 25, 2019 by Brian Benchoff 51 Comments

Unless you’re one of the cool people who uses the same password everywhere, you might be in need of a hardware device that keeps your usernames and passwords handy. The Passkeeper is a hardware password storage system built on a Raspberry Pi. It encrypts your passwords, and only through the magic of a special key fob will you ever get your passwords out of this device.

The hardware for this device is built around the Raspberry Pi Zero. You might be questioning the use of a Pi Zero, but given that it’s an entire Linux system for just a few bucks, it only makes sense. The rest of the hardware is a tiny OLED SPI display, an RFID card reader, a few LEDs, some wire, and some solder. A 3D printed case keeps everything together.

Of course, this build is all about the software, and for that, the Passkeeper device is built in Go, with a system that builds a web interface, builds the firmware, and writes everything to an SD card. Usage is simply plugging the Passkeeper into the USB port of your computer where it presents itself as a network interface. Everything is available by pinging an IP address, and after that the web UI will log your usernames and passwords. All this data is encrypted, and can only be unlocked if an RFID key fob is present. It’s an interesting idea and certinaly inexpensive. It’s not quite as polished as something like the Mooltipass, but if you have a Pi around and don’t have a password keeper, this is something to build this weekend.