You’ve Never Seen This RetroPie Emulator Console: Watermelon

The Raspberry Pi is a hugely popular platform for emulating older consoles, with the RetroPie framework making it easy to get started in no time at all. Often, these single board computers get built into fun arcade boxes or replica console shells to add to the charm. That’s all been done, so instead, [Cedishappy] decided to go in his own direction – resulting in the wonderful Watermelon Gameboy.

What sounds like a trivial exercise of building a RetroPie rig in a unique enclosure actually comes with some engineering challenges. The basics are all pretty standard – GPIO pins interfacing buttons, a speaker and the screen, emulating a Gameboy Advance. But the mechanical implementation is more complex. The watermelon is first cut open, having its red flesh removed, leaving just the rind. Paper and cardboard templates are then used to make holes for the buttons and screen. Unfortunately, hot glue doesn’t work on watermelon, so instead, toothpicks were used to hold the screen and speaker in place. To protect the electronics from the moist melony environment inside, clear food wrap was applied to the Raspberry Pi and other components where needed.

[Cedishappy] goes above and beyond with the project video charmingly showing the reactions of bystanders to the contextually confusing game system. The combination of electronics with fruit and vegetables is an area we don’t see explored often enough; our own [Mike Szczys] built a magnificent LED Jack-o-Lantern that really looks the business. Video after the break.

Continue reading “You’ve Never Seen This RetroPie Emulator Console: Watermelon”

Sunrise, Sunset, Repeat

Sunrises and sunsets hardly ever disappoint. Still, it’s difficult to justify waking up early enough to catch one, or to stop what you’re doing in the evening just to watch the dying light. If there’s one good thing about CCTV cameras, it’s that some of them are positioned to catch a lovely view of one of the two, and a great many of them aren’t locked down at all.

[Dries Depoorter] found a way to use some of the many unsecured CCTV cameras around the world for a beautiful reason: to constantly show the sun rising and setting. Here’s how it works: a pair of Raspberry Pi 3B + boards pull the video feeds and display the sunrise/sunset location and the local time on VFD displays using an Arduino Nano Every. There isn’t a whole lot of detail here, but you can probably get the gist from the high-quality pictures.

If you wanted to recreate this for yourself, we might know where you can find some nice CCTV camera candidates. Just look through this dystopian peephole.

Thanks for the tip, [Luke]!

Evaluating Raspberry Pi As A Programmable Logic Controller

It should be no surprise to many that one can use a Raspbery Pi SBC as an industrial controller, but is it any good at that? That was the question which [Dough Reneker] and [William Shaffer] built a test rig to see how a Raspberry Pi performs in head to head tests. They compared a Python-based control loop on a Raspberry Pi 3B against an C0-12DD1E-2-D AutomationDirect CLICK Programmable Logic Controller (PLC) using a simple water heating example.

A major snag with using the Raspberry Pi as a PLC is the lack of industrial I/O capacity. This requires additional hardware, in this case adding a four-channel ADC board as well as a custom board to condition the signals. The Raspberry Pi looks for 0-3 V inputs where industrial control applications are usually in the -10 to 10 V range and often use a 4-20 mA current loop.

Using a PLC leverages so-called ladder logic, where each action depends on conditions. With each update scan, the PLC ensures that all input conditions are translated into the appropriate output conditions in real-time. It’s only job is to monitor the process at hand and it does this very well.

Here the flexibility and generic nature of the Raspberry Pi running Linux was a disadvantage. Unlike the PLC, the lack of a hard real-time OS means you can’t guarantee the Pi will be as responsive to changing inputs.

The behavior of the two systems showed that while both did the task they were programmed for, the Raspberry Pi was decidedly more erratic. Although one could program around a lot of these issues (presumably using Linux in stripped-down, soft real-time configuration with interrupt-driven native code), the effort needed to make a Raspberry Pi system suitable for an industrial environment shows why single-board computers haven’t seen adoption as replacements for PLCs.

Continue reading “Evaluating Raspberry Pi As A Programmable Logic Controller”

Raspberry Pi Makes A Practical Tricorder

What do you get when you add a thermal camera, a software-defined radio dongle, and a battery to a Raspberry Pi? If you are [saveitforparts] you make a tricorder for sniffing radio signals and viewing heat signatures. He admits, the videos (see below) aren’t exactly a “how-to” but it will still give you some ideas for your next build.

You can sense the frustration with some Linux configuration issues, but [saveitforparts] admits he isn’t a Linux or Raspberry Pi guru. Version 1 seemed to be a bit of a prototype, but version 2 is more polished. We still aren’t sure we’d see Spock carrying a case like that, but some 3D printing could spiff that right up.

Of course, a real tricorder is a McGuffin that does whatever the plot calls for. This one is a bit more practical, but it can monitor thermal and RF energy and could accommodate more sensors. This is a great example of a project that would have been very hard to do in the past but is much easier today. The availability of cheap computers and ready-made modules along with associated software open up many possibilities.

If you want to do your own Tricorder hacking you could take over a commercial model. Then again, there’s an official replica on its way that seems like it might have some similar features.

Continue reading “Raspberry Pi Makes A Practical Tricorder”

Student Rover Explores The Backyard In Tribute

Three students were a little sad when NASA’s Opportunity rover went silent after 15 years on the Martian surface. So they decided to build their own rover inspired by Opportunity to roam their backyards using an off-the-shelf robot chassis, a Raspberry Pi, and the usual list of parts like motors, H-bridges, and batteries.

Like the real rover, the vehicle uses a rocker-bogie system, although it is a little less complex than the version NASA sent blasting off towards the Red Planet. The plucky vehicle comes complete with miniature solar panels to recharge its onboard battery, courtesy of some dollar-store garden lights. A pair of videos after the break show how the rover is controlled, as well as the view sent back from its onboard camera.

The rover ran a simulated Mars mission as part of a school project where it had to find an object and transmit an image of it back to home base, and by the looks of it, is was a rousing success. But the young explorers aren’t resting on their laurels, and are already working on a second version of their exploration vehicle that can operate in inclement weather and includes some new tools such as a robotic arm and infrared illumination for low-light imaging.

We’ve seen plenty of Mars rover clones in the past, but there’s always room for more. Of course, if you’re looking for something a bit easier to start with, you can always go the LEGO route.

Continue reading “Student Rover Explores The Backyard In Tribute”

Building The Ultimate Raspberry Pi Automation Controller

At this point, we’ve lost count of how many automation projects we’ve seen with some variant of a Raspberry Pi at the helm. Which is hardly surprising, as the boards are cheap, powerful, and well documented. The list of reasons not to use one has never been very long, but with the PiCon One that [Frank] has been working on, it’s about to get even shorter.

The project takes the form of an IP65 industrial enclosure and support electronics that the Raspberry Pi Zero W plugs into. While expandable in nature, [Frank] has a core set of features he’s aiming for as a baseline such as additional serial ports, integrated uninterruptible power supply, a battery-backed Real Time Clock (RTC), an array of programmable status LEDs, and support for XBee and GPS plug-in modules. Feedback is provided through a pair of four digit seven-segment displays and a color 320×480 TFT screen running a custom user interface.

[Frank] envisions the PiCon One for use as a rugged solar power controller, eventually able to measure array output, energy consumption, and even operate motorized mounts to keep the panels pointed at the sun. To that end, he’s recently been experimenting with running JPL’s Horizon software on the Pi to determine the sun’s position in real-time. But the device is capable of so much more, and would make an ideal controller for many home and potentially even industrial applications.

Continue reading “Building The Ultimate Raspberry Pi Automation Controller”

Pi Saves Vintage Mac Case From A Watery Grave

Like many before it, this Mac 512K case was originally slated to get turned into a kitschy desktop aquarium. But its owner never found the time to take on the project, and instead gave it to [Tony Landi]. Luckily, he decided to forgo the fish and instead outfit the case with a new LCD display and Raspberry Pi to emulate Mac OS 7.5.

Mounting the LCD and associated electronics.

In the video after the break, [Tony] walks viewers through the process of mounting the new components into the nearly 30+ year old enclosure. Things are naturally made a lot easier by the fact that the modern electronics take up a small fraction of the Mac’s internal volume. Essentially the only things inside the case are the 10 inch 4:3 LCD panel, the Raspberry Pi, and a small adapter that turns the Mac’s pre-ADB keyboard into standard USB HID.

[Tony] had to design a 3D printed adapter to mount the modern LCD panel to the Mac’s frame, and while he was at it, he also came up with printable dummy parts to fill in the various openings on the case that are no longer necessary. The mock power switch on the back and the static brightness adjustment knob up front are nice touches, and the STLs for those parts will certainly be helpful for others working on similar Mac conversions.

With the hardware out of the way, [Tony] switches gears and explains how he got the emulated Mac OS environment up and running on the Raspberry Pi. Again, even if you don’t exactly follow his lead on this project, his thorough walk-through on the subject is worth a watch for anyone who wants to mess around with Apple software from this era.

Continue reading “Pi Saves Vintage Mac Case From A Watery Grave”