Kategorie: Technology

It’s refreshing that newer doesn’t always have to mean bigger and better. I’ve been using a Raspberry Pi 4 for the last few years as a desktop Linux machine, and although it could be faster, then thing that holds me back from upgrading it is nothing to do with the Pi itself. It’s the peripherals: if I moved to a Raspberry Pi 5 I’d have to get new headphones, as the Raspberry Pi 5 moved away from a 3.5mm headphone jack. I’d have to spend money on headphones that use Bluetooth, and forever be losing them or running out of charge. I realise this makes me unusual in the world of the tech enthusiast, but once I get something that works, I just don’t want to go to the effort of changing it.

That may make me an outlier in terms of individuals, but there’s another consumer sector that really wants to be able to get the bare minimum and stick with it: businesses. Upgrading is a cost. Buying new cables because the new version of a device uses USB-C instead of Micro USB is a cost. Any change at all imposes a cost, and if you can avoid that, you’re winning.

We all know that things like connectivity and processing speed are features. But price is also a feature, and a really big one. So too is backward compatibility. If I don’t want to buy a new thing because it messes with my minimal setup of screen, keyboard, mouse and headphones, then it’s vanishingly unlikely that I’d invest in a new device if it meant I would have to build a whole new factory to accommodate it.

It’s great there are new devices to play with. But it’s even greater knowing that you can buy one, and build it into your project, or your product, or even your manufacturing setup, in confidence that it won’t be rendered obsolete by the next new model. It sounds counter-intuitive, but that’s how you keep customers coming back: not by locking them in, but by making it clear that they don’t have to upgrade if they don’t want to.

Thomas Killus has created such a brolly using a Raspberry Pi Pico microcontroller board. It sends instructions to strips of standard WS2812b addressable RGB LEDs that run along the ribs of an umbrella, and this in turn brightly disperses light across the adjoining panels. The umbrella would certainly shine bright in a crowd and maybe even prevent it being left behind on the bus. But it’s also, curiously, the first step towards something bigger.

“I have always been fascinated with beautiful light installations,” Thomas says. “My dream is to someday build a complete LED suit that can either be pre-programmed or made to interact with the environment through sensors. It would be nothing practical, but I hope to bring a smile to the people around me and myself. I thought an umbrella would be a small step into this direction.”

Brolly good

Planning the umbrella was straightforward enough. “Get an umbrella, get LEDs and put them together,” Thomas explains. In the past he had tended to use an ESP32 microcontroller for his hardware projects and Python for his pure software projects. “But one day I saw a Raspberry Pi Pico microcontroller in a store and I recognised the great potential of finally using Python in my hardware projects, so I knew I had to give it a try,” he explains.

The idea was to create a set of pre-programmed animations that could be easily skipped through by simply pressing a button. These animations were created on a PC using a simulator Thomas had developed in Pygame. They were then saved to an SD card which plugged into the umbrella. “Raspberry Pi Pico can read the animation data and control the LEDs accordingly,” he explains. “I thought this way, I wouldn’t have to limit the animations by the computer power or memory limitations of Raspberry Pi Pico.”

Development went reasonably well. “It didn’t cause me major headaches,” Thomas says. “But in the beginning, I had some issues with reading the animation commands fast enough from the SD card while displaying them live but I eventually figured it out using byte files.”

Shine a light

There are some features he would like to implement, though. Thomas originally planned to also add an MPU9250 nine-axis motion tracking sensor to measure acceleration, rotation and orientation. “I wanted to add features which will make the umbrella change its lights when you spin it, jump or turn into a different direction and I hoped it would give the user more interactions with the umbrella,” he says.

Thomas also wants to reduce the number of visible cables and make the underneath “sparkle with the same joy,” as he puts it. “LED light isn’t diffused on this side and it takes away a lot of the effect,” he laments. Even so, the umbrella has gone down well among the Raspberry Pi community even though many say it has no practical use. “I guess they are right,” he says. “But I enjoyed building it, I learned some things and it made me smile when it lit up for the first time.”

You don’t have to use this little dock mechanism – we can definitely imagine 3D-printing an enclosure that sticks to the back of the lid with a few cables between the laptop and Raspberry Pi. However you choose to connect your Raspberry Pi though, it doesn’t require any extra software setup and is immediately good to go, which is very nice.

Take it with you

As there are no computer parts inside the shell, the whole thing is very light, even with a Raspberry Pi attached to it (although it does throw off the balance a little). The heaviest part of the assembly is probably the 5,000mAh battery, which charges nice and quickly, although only with the included DC barrel jack. With a Raspberry Pi plugged in the battery lasts for a couple of hours just fine with fairly normal use, and you can also check the battery with a touch of a button.

Perhaps due to either how light it is, or the materials used in construction, but the Note does feel a little bit flimsy while using it. The mousepad is fine, however the physical clicks for right and left click feel clunky and only work near the bottom of the touchpad. Compared to other normal laptops the keyboard is actually pretty good though, and is nice to type on – it has an extra bit of resistance that makes the keys satisfying to use.

Multi-purpose

We didn’t find much use for it with our other PCs – although we don’t have any mini PCs like a Mac Mini or such around, which seems like a good fit for the CrowView. It’s quite nice for watching videos from a phone though, especially if you’re travelling and don’t want to lug a regular, heavier laptop around with you.

However, it’s as a Raspberry Pi dock that it really shines for us, and despite our concerns with the build quality and awkwardness of the provided dock system, it works more than well enough that we’re definitely going to be using it in the future instead of juggling cables on monitors and PSUs. We might use a Bluetooth mouse though.

Verdict

9/10

There are some minor build quality issues but the product itself is fantastic and does exactly what you’d want it do.

Specs

Display: 14-inch IPS, 1920×1080

Battery: 5000mAh

I/O: Keyboard, touchpad, mouse, webcam, USB A, USB-C, speakers, 3.5mm headphone jack, mini HDMI in

This little device includes a mechanical keyboard that, Michael says: was his primary motivation for making his retro marvel. Having first cut his teeth learning BASIC on a Sharp PC-1260, he quickly became a fan of portable computers and snapped up many more. But when, in recent years, he sought to revive his interest in such machines, he said he’s been left disappointed.

“I have tried Raspberry Pi and Linux-compatible portables and laptops but I’ve never been really satisfied with their keyboards,” he says, name-checking the Pocket C.H.I.P, Devterm and uConsole projects. “Even at work I used a mechanical keyboard with the company laptop so I started to search for smaller keyboards and portable Raspberry Pi projects. I then found ZeroWriter.”

Key to success

ZeroWriter is an open e-ink typewriter with a Raspberry Pi Zero 2 W board at its heart. Michael decided to create one for himself, and ordered the Vortex Core 40% keyboard while swapping out the WaveShare 4.2-inch e-paper display with a Waveshare five-inch monitor. “As there was still space, I added a speaker to the side,” he adds. “But the project was limited in terms of the Python audio effects development I wanted to pursue.”

Michael decided to take the project to another level, hence the use of Raspberry Pi 4. “With the experience of my first build, it was clear that I should go bigger and I also searched for another keyboard,” he says. Looking on pcbway.com, he found the Happy Keyboard, a 47-key, 40% ortholinear mechanical keyboard that uses a Raspberry Pi Pico development board running KMK firmware. It formed the basis of the design for the entire project.

“I started with the keyboard because it was the single largest part of the build,” he explains, adding that the next step was to find a display. “I searched for a screen with vertical resolution bigger than 400 or 480, and found a 9.3-inch display by Waveshare with a funky resolution of 1600×600 which fitted perfectly to the 40% keyboard.” This setup dictated the design of the project’s case, and it helped that every Waveshare screen comes with a CAD file and audio amplifier.

“It was all natural and fell into place because of the size of the components and the requirement that the keyboard should be as low as possible,” Michael says. “Somehow I loved the wide display more than a normal 16:9 display, so this may be the reason for the centred screen.”

A great case

Other design considerations needed to be considered. “It was clear in the beginning that the Raspberry Pi 4 and the battery would have to sit behind the keyboard,” Michael says, having decided to place them in a sizable rear compartment. The Raspberry Pi Pico development board also needed to be moved because there wasn’t sufficient room on the main keyboard PCB.

In extending the back section by up to two centimetres and increasing its height to match that of the screen and keyboard, Michael found space to fit audio speakers. He worked on ways of being able to use the USB ports, too, by creating insert panels on the back of the case for flexibility. “Instead of having to print an entire case, taking tens of hours, every time I decided I’d want to reconfigure the ports, I could just print new panels, which takes about an hour,” he explains.

Even so, there were other issues to contend with. Michael had trouble with the HDMI connection being on top of the screen. “I had to rotate it, and it took me some time to figure out how to flip the screen,” he says. “The display’s on-screen menu is still the wrong way around and this can’t be fixed, but I think that’s a Waveshare issue.”

The biggest headache, however, was power – the system draws juice from a pair of 21700 batteries connected to a UPS HAT. “I tried several battery boards but I was getting random reboots and other issues,” he says. “I then recognised that the cables I used to connect to the Raspberry Pi 4 computer were too thin. After I used better cables it worked fine. There were still some power warnings after two hours but it’s not bad.”

Powering up

Battery issues are why he decided against using a Raspberry Pi 5 board, for now at least. “If I could find a battery able to power it, I’d use Raspberry Pi 5,” he says. Michael also wants to be able to move the Raspberry Pi computer away from the side and make a side panel. “This would make it possible to use more single-board computers in the future, and help to connect the screen and keyboard to Raspberry Pi internally,” he says.

But he’s more than happy with the result so far and he says it’s a build that has fulfilled his requirements. “It’s also been a good way to learn FreeCAD which was fun most of the time – there was a lot of cursing before understanding, though.” He uses the device for programming and watching streams and finds it to be very convenient. “It’s easy to fetch and can be placed on the couch or kitchen table without taking up much room,” he says. And that, in a nutshell, is what a portable computer should be like.

You can buy the Plasma 2350 board on its own or in a Starter Kit (£34.50 / $38) with a USB-A to USB-C cable and 10m string of 66 individually addressable frosted LED stars. These look superb when lit up, and are a great way of showcasing the capabilities of the Plasma 2350. We also tried out a long 300-LED strip and there was easily enough current (up to 3A) from the USB-C power connection to light them all.

Wired for light

Connecting your LED string or strip to the board is simple. As on the Plasma 2040, there are four screw terminals on one end: for 5V power, data, clock, and ground. While WS2812/NeoPixel LED strips have only three wires, omitting the clock connection, the latter is needed for DotStar LEDs. A little care needs to be taken to make sure each wire is in the correct terminal and that they’re screwed securely.

Despite coming in a slimmer ‘gum stick’ form factor than the Plasma RP2040, the board manages to cram in many useful features. There’s an unpopulated header down one long edge to break out selected GPIO pins, offering access to UART and I2C interfaces, along with analogue inputs, PWM outputs, and PIO state machines. There’s also a Qwiic/STEMMA QT connector for breakout boards, as well as Pimoroni’s new proprietary SP/CE (Serial Peripheral / Connector Evolution) port – an eight-pin JST-PH connector including four pins for SPI.

Buttons for everything

One slight downside of the SP/CE’s inclusion is that there’s no room for a B user button next to the A one (as on the Plasma 2040), although the Boot button doubles as a user input. There’s also a handy Reset button, to save repeatedly disconnecting and connecting the USB-C power. An on-board RGB LED is a nice touch, too.

Before you can start programming some light patterns, you’ll need to install MicroPython. In its RP2350 GitHub repo, Pimoroni provides a custom UF2 file for the Plasma 2350. To install it, connect the board to your computer via USB while holding the Boot button, to mount it as a drive, then drag the file over to it. Alternatively, if you prefer CircuitPython, with which you can utilise Adafruit’s excellent LED Animation library, there’s also a UF2 image for that.

Using MicroPython in the Thonny IDE, we tried out some code examples from Pimoroni’s GitHub repo, altering the constant for the number of LEDs to match our string. While there are only a few examples there – including a nice ‘rainbow’ colour-cycling effect – we found that most of the ones for the Plasma 2040 and Plasma Stick 2040 W still work. Impressive lighting effects include alternating/random blinkies, sparkles, snowfall, fire, pulsing and a lovely rainbow sweeping across the string of LEDs.

Since the Plasma 2350 lacks on-board Wi-Fi, you can’t get your LEDs to react to data from the network, but you could always connect a breakout input such as a temperature sensor.

Verdict

9/10

An easy way to control NeoPixel/DotStar LED strings with programmable effects, with extra processing power if you need it.

Features

Features: RP2350A processor; Boot, Reset, and user buttons; on-board RGB LED

LED compatibility: 5V WS2812/NeoPixel, APA102/DotStar

Connections: 4 × screw terminals, USB-C port for power/programming, Qwiic/STEMMA QT, SP/CE, unpopulated 15-pin GPIO header