Simplifying The Ruggedized Raspberry Pi Portable

October 19, 2020 by Tom Nardi 37 Comments

Over the last year we’ve seen a wave of portable computer builds that center around the Raspberry Pi taking up residence inside a commercial heavy-duty storage case. It’s not hard to see why; whether you spring for the Pelican case or get a cheaper alternative, these water-tight cases are far stronger than anything you’re going to 3D print or otherwise cobble together in the home shop. Especially if you can avoid popping any holes in the side.

Inspired by these builds but looking to make it even easier and cheaper to roll your own version, [Dmitry] recently took the wraps off of what he calls the Militarish Pi. You don’t need a CNC to cut out any face plates or a 3D printer to create an internal framework for all your components. You could even do it without soldering anything, if you really wanted to. Short of just buying one of these rigs pre-built from somebody, it’s hard to imagine it could get much easier than this.

Most of the effort involves cutting the PVC foam sheet that holds the Raspberry Pi, battery pack, and the driver board for the LCD in the bottom of the $15 USD case [Dmitry] managed to track down on AliExpress. The “carbon fiber” sticker he put on the PVC sheet won’t do much for the structural integrity of the build, but it sure looks nice. Of course if you have access to the appropriate tools, you could certainly cut the plate out of something stouter. As for the display, the nine inch LCD is perfectly sized to press fit into the lid.

Rounding out the build, [Dmitry] found a cheap Android phone case that included a tiny USB keyboard which plugs right into the Pi and he’s looking to add a BlackBerry trackball to the setup down the line. We especially like the large open area that he’s kept around the Raspberry Pi’s ports that allow you to easily hook up to the network or plug in a flash drive. It could also be a nice compartment to keep your RTL-SDR for some mobile radio work.

For those that don’t mind spending name-brand money and have access to a 3D printer, the Raspberry Pi Quick Kit by [Jay Doscher] is another great way to get yourself a rough and tumble Pi without reinventing the wheel.

Escape To An Alternate Reality Anywhere With Port-A-Vid

October 19, 2020 by Roger Cheng 26 Comments

There was a time when only the most expensive televisions could boast crystal clear pixels on a wall-mountable thin screen. What used to be novelty from “High Definition Flat Screen Televisions“ are now just “TV” available everywhere. So as a change of pace from our modern pixel perfection, [Emily Velasco] built the Port-A-Vid as a relic from another timeline.

The centerpiece of any aesthetically focused video project is obviously the screen, and a CRT would be the first choice for a retro theme. Unfortunately, small CRTs have recently become scarce, and a real glass picture tube would not fit within the available space anyhow. Instead, we’re actually looking at a modern LCD sitting behind a big lens to give it an old school appearance.

The lens, harvested from a rear-projection TV, was chosen because it was a good size to replace the dial of a vacuum gauge. This project enclosure started life as a Snap-On Tools MT425 but had become just another piece of broken equipment at a salvage yard. The bottom section, formerly a storage bin for hoses and adapters, is now home to the battery and electronics. All original markings on the hinged storage lid were removed and converted to the Port-A-Vid control panel.

Before: broken Snap-On MT425

After: An escape portal. Please stand by…

A single press of the big green button triggers a video to play, randomly chosen from a collection of content [Emily] curated to fit with the aesthetic. We may get a clip from an old educational film, or something shot with a composite video camera. If any computer graphics pop up, they will be primitive vector graphics. This is not the place to seek ultra high definition content.

As a final nod to common artifacts of electronics history, [Emily] wrote an user’s manual for the Port-A-Vid. Naturally it’s not a downloadable PDF, but a stack of paper stapled together. Each page written in the style of electronics manuals of yore, treated with the rough look of multiple generation photocopy rumpled with use.

If you have to ask “Why?” it is doubtful any explanation would suffice. This is a trait shared with many other eclectic projects from [Emily]. But if you are delighted by fantastical projects hailing from an imaginary past, [Emily] has also built an ASCII art cartridge for old parallel port printers.

Continue reading “Escape To An Alternate Reality Anywhere With Port-A-Vid” →

New Raspberry Pi 4 Compute Module: So Long SO-DIMM, Hello PCIe!

October 19, 2020 by Elliot Williams 151 Comments

The brand new Raspberry Pi Compute Module 4 (CM4) was just released! Surprised? Nope, and we’re not either — the Raspberry Pi Foundation had hinted that it was going to release a compute module for the 4-series for a long while.

The form factor got a total overhaul, but there’s bigger changes in this little beastie than are visible at first glance, and we’re going to walk you through most of them. The foremost bonuses are the easy implementation of PCIe and NVMe, making it possible to get data in and out of SSDs ridiculously fast. Combined with optional WiFi/Bluetooth and easily designed Gigabit Ethernet, the CM4 is a connectivity monster.

One of the classic want-to-build-it-with-a-Pi projects is the ultra-fast home NAS. The CM4 makes this finally possible.

If you don’t know the compute modules, they are stripped-down versions of what you probably think of as a Raspberry Pi, which is officially known as the “Model B” form-factor. Aimed at commercial applications, the compute modules lack many of the creature comforts of their bigger siblings, but they trade those for flexibility in design and allow for some extra functionality.

The compute modules aren’t exactly beginner friendly, but we’re positively impressed by how far Team Raspberry has been able to make this module accessible to the intermediate hacker. Most of this is down to the open design of the IO Breakout board that also got released today. With completely open KiCAD design files, if you can edit and order a PCB, and then reflow-solder what arrives in the mail, you can design for the CM4. The benefit is a lighter, cheaper, and yet significantly more customizable platform that packs the power of the Raspberry Pi 4 into a low-profile 40 mm x 55 mm package.

So let’s see what’s new, and then look a little bit into what is necessary to incorporate a compute module into your own design.

Continue reading “New Raspberry Pi 4 Compute Module: So Long SO-DIMM, Hello PCIe!” →

Cheap All-Sky Camera Is Easy As Pi

October 14, 2020 by Kristina Panos 28 Comments

Combining a Raspberry Pi HQ camera and a waterproof housing, [jippo12] made an all-sky, all-Pi meteorite tracking camera on the cheap, and it takes fantastic photos of the heavens. It’s even got its own YouTube channel. Inside there’s a Raspberry Pi 4 plus an HQ camera to take the pictures. But there’s also a system in place to keep everything warm and working properly. It uses a Raspberry Pi 3+, a temperature sensor, and a relay control HAT to pump pixies through a couple of 10 W resistors, making just enough heat to warm up the dome to keep it from fogging.

A few years ago, we reported that NASA was tracking meteorites (or fireballs, if you prefer) with a distributed network of all-sky cameras — cameras with 360° views of the night sky. Soon after, we found out that the French were doing something quite similar with their FRIPON network. We pondered how cool it would be to have a hacker network of these things, but zut alors! Have you seen the prices of these things? Nice hack, [jippo12]!

Rather do things the old fashioned way? Dust off that DSLR, fire up that printer, and check out OpenAstroTracker.

Running Way More LED Strips On A Raspberry Pi With DMA

October 12, 2020 by Lewin Day 18 Comments

The Raspberry Pi is a powerful computer in a compact form factor, making it highly useful for all manner of projects. However, it lacks some of the IO capabilities you might find on a common microcontroller. This is most apparent when it comes to running addressable LED strings. Normally, this is done using the Pi’s PWM or audio output, and is limited to just a couple of short strings. However, [Jeremy P Bentham] has found a way to leverage the Pi’s hardware to overcome these limitations.

The trick is using the Raspberry Pi’s little-documented Secondary Memory Interface. The SMI hardware allows the Pi to shift out data to 8 or 16 I/O pins in parallel using direct memory access (DMA), with fast and accurate timing. This makes it perfect for generating signals such as those used by WS2812B LEDs, also known as NeoPixels.

With [Jeremy]’s code and the right supporting hardware, it’s possible to run up to 16 LED strips of arbitrary length from the Raspberry Pi. [Jeremy] does a great job outlining how it all works, covering everything from the data format used by WS2812B LEDs to the way cache needs to be handled to avoid garbled data. The hack works on all Pis, from the humble Pi Zero to the powerful Pi 4. Thanks to using DMA, the technique doesn’t overload the CPU, so performance should be good across the board.

Of course, there are other ways to drive a ton of LEDs; we’ve seen 20,000 running on an ESP32, for example.

[Thanks to Petiepooo for the tip!]

HALWOP Recreates Retro Style With The Raspberry Pi

October 12, 2020 by Tom Nardi 5 Comments

Modern computers are incredible feats of engineering, but there are many that still yearn for the simpler times. When keyboards clacked and a desktop computer quite literally dominated the top of your desk. There’s a whole community of folks who scratch that itch by restoring vintage computers, but not everyone has the time, money, or skill for such pursuits. Plus, even the most lovingly cared for Apple II isn’t going to help you watch YouTube.

Those who wish to recreate the look and feel of a vintage computer with modern internals will certainly be interested in the HALWOP by [Maz_Baz]. While its 3D printed case isn’t a replica of any one computer, it does draw inspiration from iconic machines like the Apple Lisa and IBM XT. It’s an amalgamation of design ideas that seemed like a good idea circa 1982 or so, with plenty of 90° angles and air vents to go around.

Considering the size of the Raspberry Pi 4 that powers the HALWOP, most of the case is just hollow plastic. But of course, the whole idea depends on it being almost comically large. On the plus side, [Maz_Baz] says you can use one of those empty compartments to hold a Anker PowerCore 26800 battery pack. At least in theory that makes it a “luggable” computer, though good luck trying to move it around.

In addition to the Pi 4 and battery pack, the HALWOP also uses a seven-inch touch LCD and Keychron K2 Bluetooth mechanical keyboard. Since everything is so modular, assembly is about as simple as it gets. Outside of the USB cables that power everything, you just need a long enough ribbon cable to connect the LCD to the Pi.

We know the purists don’t like the idea of a “retro” computer based on the Raspberry Pi, but of course, such projects aren’t about maintaining historical accuracy. They are a way to bridge the gap between modern technology and the unique aesthetics of a bygone era. Designs like the HALWOP allow a new generation to experience a taste of what computing was like in the early days, without giving up the ground that’s been gained in the intervening years.

Lo-Fi Art On A 32×32 Matrix

October 11, 2020 by Tom Nardi 15 Comments

Display technology has improved by leaps and bounds over the last few years, thanks in no small part to the smartphone revolution. High-resolution LCD panels are dirt cheap and easy to interface with. There’s absolutely no logical reason to try and show images on a 32×32 array of RGB LEDs. But that didn’t stop [Felix Spöttel] from doing it anyway.

The project, which he calls thirtytwopixels, was designed to work in conjunction with MPD (Music Player Daemon) to show the album art for whatever is currently playing. The ultra-low resolution display added a certain element of abstractness to the artwork, which [Felix] said made it an interesting conversation starter. Guests would try and guess what the album art was depicting given the sparse rendition shown on the matrix.

[Felix] gives an excellent explanation of how to get the server and client-side software up and running should you want to recreate his setup, but his Python scripts also have a function where you can push an arbitrary image to the display if you don’t want to connect everything up to the MPD backend.

On the hardware side, thirtytwopixels uses the Raspberry Pi Zero W, a Adafruit RGB Matrix Bonnet, and a 32×32 LED matrix that uses the HUB75 interface. Even a relatively small LED matrix like this can get pretty thirsty, so [Felix] is using a 5 volt power supply that can deliver 4 amps to keep the electronics happy.

If you wanted to keep the low resolution aesthetic but make the display larger, we’ve seen WS2812B LED strips and 3D printed frames used to make a custom jumbo matrix which could surely be adapted for this concept.