A 3D-printed, split-flap display-having calculator with a Raspberry Pi Pico inside.

By Our Calculations, You’ll Love The Flapulator

Oh sure, you’ve got calculators. There’s that phone program of course, and the one that comes with your OS, and the TI-86 and possibly RPN numbers you’ve had since high school.

But what you don’t have is a Flapulator, at least not until you build one. Possibly the be-all, end-all of physical calculating devices, the Flapulator does its calculating live on a split-flap display. It’s kind of slow and the accuracy is questionable, but the tactility is oh, so good.

This baby boasts a 6-digit display, where the decimal point and negative sign each require one digit. Inside is a Raspberry Pi Pico, which can calculate for around 4 hours on a full charge. But the coolest part (aside from the split-flap display, naturally) has got to be the 24-key, hand-wired mechanical keyboard. There’s also a couple of LEDs that light up to keep track of the current mathematical operation.

The story behind this one is kind of interesting. [Applepie1928] found out that one of their favorite mathematician-comedian-pi-lovers who is known for signing calculators was coming to town. With four weeks to whip something up, this was, amazingly, the result. Check it out in  action after the break.

Need something that’s a whole other kind of fancy? Here’s an open-source graphing calculator.

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We’re All Abuzz About The Bee Write Back Writerdeck

Friends, there will likely come a time in your life when you have trouble sleeping. When this happens, it may behoove you to do some writing, any kind of writing. But consider that a physical journal will force you to turn past pages you’ve already filled, which may leave you deflated if you happen to read them.

So the answer lies in a sort of journalistic deposit box. That’s basically what we have here. [Simon Shimel]’s Bee Write Back writerdeck was inspired by sleepless nights, so you know it’s effective. The form factor is so great for [Simon], in fact, that he has developed more apps and functions for it, including a Claude client.

Inside is a Raspberry Pi Zero 2w, and input comes from an Air40 keyboard with quite awesome low-profile key caps. The display is a 5.5″ AMOLED, which leaves just enough room for a pair of the cutest bees ever. Be sure to check out the short video below for the build guide to accompany the build guide (PDF), and head over to GitHub for the full details.

Want to go even smaller and BYOK? Here’s a cheap writerdeck with an e-ink display.

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2026 Green Powered Challenge: Solar Powered Pi Hosts Websites In RAM

If you started with computers early enough, you’ll remember the importance of the RAMdisk concept: without a hard drive and with floppies slow and swapping constantly, everything had to live in RAM. That’s not done much these days, but [Quackieduckie]’s solar powered Pi Zero W web server has gone back to it to save its SD card.

Sustainability and low power is the name of the game. Starting with a Pi Zero W means low power is the default; a an SLS-printed aluminum case that doubles as the heat sink– while looking quite snazzy–saves power that would otherwise be used for cooling. The STLs are available through the project page if you like the look and have a hankering for passively cooled Pi. Even under load [Quackieduckie] reports temperatures of just 29.9°C,  less than a degree over idle.

The software stack is of course key to a server, and here he’s using Alpine Linux running in “diskless mode”– that’s the equivalent of what us oldsters would think of as the RAMdisk. That’s not that unusual for servers, but we don’t see it much on these pages. It’s a minimal setup to save processing, and thus electrical power, with only a handful of services kept running: lighttpd, a lightweight webserver, and duckiebox, a python-based file server, along with SSHD and dchron; together they consume 27 MB of RAM, leaving the rest of the 512 MB DDR2 the Pi comes with to quickly serve up websites without the overhead of SD card access.

As a webserver, [Quackieduckie] tested it with 50 simultaneous connections, which would be rather a lot for most small, personal web sites, and while it did slow down to an average 1.3s per response that’s perfectly usable and faster than we’d have expected from this hardware. While the actual power consumption figures aren’t given, we know from experience it’s not going to be drawing more than a watt or so. With a reasonably sized battery and solar cell– [Quackieduckie] suggests 20W–it should run until the cows come home.

This isn’t the first solar-powered web server we’ve seen, but this one was submitted for the 2026 Green Powered Challenge, which runs until April 24th.

The Raspberry Pi 4 With 3 GB RAM Is No Joke

Raspberry Pi 5 price increases. (Credit: Jeff Geerling)
Raspberry Pi 5 price increases. (Credit: Jeff Geerling)

Although easily dismissed by some as another cruel April Fools joke, Raspberry Pi’s announcement of a new 3 GB model of the Raspberry Pi 4 along with (more) price increases for other models was no joke. Courtesy of the ongoing RAMpocalypse, supplies of LPDDR4 and LPDDR5 are massively affected, leading to this new RPi 4 model with two 1.5 GB LPDDR4 chips, as these are apparently cheaper to source.

Affected in this latest price increase across RP’s product range are RPi 4 and 5 models with 4 or more GB of RAM, with price bumps ranging from $25 on the low end to $150 for the Raspberry Pi 500+. If you wanted a Raspberry Pi 5 with 16 GB of RAM, you’re now paying $300 for the privilege.

Obviously, this news has got people like [Jeff Geerling] rather down in the dumps, essentially stating that using SBCs like the RPi is now beyond the means of many hobbyists. While you can still use SBCs that use e.g. LPDDR2 RAM, such as the older RPi Zero, 2 and 3 models, [Jeff] himself is now moving more towards wrangling with snakes on MCUs, as these boards are so far not significantly affected in terms of price.

With current projections in the RAM market being that this year will still see more price increases, it remains hard to tell exactly how ‘temporary’ this situation will be. That said, using readily available, powerful and cheap MCUs like the ESP32 variants for projects isn’t a bad idea if you really don’t need to be running more than perhaps FreeRTOS.

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Last Year In SBCs

While it might not be comprehensive, [Bret.dk] recently posted a retrospective titled “Every Single Board Computer I Tested in 2025.” The post covers 15 boards from 8 different companies. The cheapest board was $42, but the high-end topped out at $590.

We like the structure of the post. The boards are grouped in an under $50 category, another group for $50-100, and a final group for everything north of $100. Then there’s some analysis of what RAM prices are doing to the market, and commentary about CIX P1, Qualcomm, RISC-V, and more.

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Experiment With The Pi Camera The Modular Way

The various Raspberry Pi camera modules have become the default digital camera hacker’s tool, and have appeared in a huge number of designs over the past decade. They’re versatile and affordable, and while the software can sometimes be a little slow, they’re also of decent enough quality for the investment. Making a Pi camera can be annoying though, because different screens, lenses, and modules have their own mounting requirements. [Jacob David C Cunningham] has a solution here, with a modular Raspberry Pi camera, as an experimentation platform for different screens and lenses.

It takes the form of a central unit that holds the Pi and its support components, and front and rear modules for the screens or displays. Examples are given using the HQ and non-HQ modules, as well as with round or rectangular displays.

When designing a camera for 3D printing it’s a very difficult task, to replicate or exceed the industrial design of commercial cameras. Few succeed, and we’d include ourselves among that number. But this one comes close; it looks like a camera we’d like to use. We like it.

The Raspberry Pi As A Studio Camera

The Raspberry Pi has brought digital camera experimentation within the reach of everybody, with its combination of an accessible computing platform and some almost-decent camera sensors. If there’s a flaw in the Pi as a camera though, it lies in the software, which can be slow and frustrating to use. [Martijn Braam] is here with an interesting project that might yield some useful results in this direction, he’s making a Raspberry Pi studio camera.

His camera hardware is very straightforward, a Pi 5 and touchscreen with the HD camera module in a rough but serviceable wooden box. The interesting part comes in the software, in which he’s written a low-latency GUI over an HDMI output camera application. It’s designed to plug into video mixing hardware, and one of the HDMI outputs carries the GUI while the other carries the unadulterated video. We can see this used to great effect with for example OBS Studio. It’s for now a work in progress as you can see in the video below the break, but we expect that it can only get better.

The video below exposes the obvious flaw in many Pi camera setups, that the available lenses don’t match the quality of the sensor, in that good glass ain’t cheap. But we think it’s one to watch, and could provide competition for CinePi.

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