Raspberry Pi Pico

136 Articles

Epson HX-20 Gets A Drive Upgrade

June 19, 2026 by 10 Comments

The Epson HX-20 is sometimes referred to as an early laptop computer. It’s a little odd in its form factor, and in its storage, relying on a microcassette drive to store data. It can be problematic to keep these tapes and drives going after so many decades, so [Andrew Menadue] has been tinkering with a more modern solution.

The replacement drive uses a Raspberry Pi Pico to emulate the original tape drive. The Pico uses a microSD card to store data instead of the magnetic media of old. The device has a small screen for showing status information and four buttons for navigation, allowing the faux drive to be controlled as to what “tape” it’s pretending to be. It’s also possible to use the device to emulate ROM cartridges that could be used with the HX-20 in place of its original tape deck storage solution.

We’ve seen some other old hardware get similar drive upgrades before, too. No surprise, because mechanical drives and media simply don’t last forever. Sometimes you need to build a replacement that’s viable today. Video after the break.

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Leaky Player Piano Gets MIDI Upgrade In YouTube Restomod

June 17, 2026 by 5 Comments

The word “restomod” is a bit nebulous, but it’s normally used in the automotive world to describe taking an old car and making it better-than-new with all the technological improvements the original builders would have used, had they been available. We think the word applies to [Alnwlsn]’s MIDI-actuated player piano, because what are those punched rolls of paper, but the MIDI of the 19th century?

Unlike a lot of automotive restomods though, this one is mostly reversible. He did drill few holes and slots in the original wood, but nowhere that it would alter the integrity or original operation of the player piano mechanism. The MIDI-controlled solenoids just poke the same key paddles from below that the pneumatic mechanism used. From the listener or operator’s perspective, unless the doors that reveal the music scroll or lack thereof are open, the piano behaves exactly the same. Except now it has access to the whole wide array of tracks that exist in MIDI form, rather than a paltry selection of hard-to-find piano rolls.

Each of the relays is driven by a MOSFET via shift registers to get 88 outputs out of the single Pi Pico in charge, with a level shifter involved to get the RP2040 speaking 5 V logic. If you’re wondering how that gets volume control, no, the piano isn’t smacking keys at full volume all the time. He’s using the RP2040’s powerful PIO to create a sort of PWM signal to soften the solenoid blows when needed. To save his power supply, he’s also got it set up to stagger the pulses, so multiple relays aren’t pulsed at the same time when the MIDI file calls for chords.

There was actually more overlap between player pianos and MIDI than you might think, given this presentation of an Apple ][ being used to create the piano rolls.

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Compact VGA Output Board For The Pi Pico

April 28, 2026 by 7 Comments

Many microcontrollers can spit out simple analog video signals if that’s something you desire. However, it normally requires a bit of supporting hardware and, of course, the right connectors to work with your other video equipment. [Arnov Sharma] took that into account when whipping up this neat VGA board for the Raspberry Pi Pico.

VGA output in this case is achieved via judicious use of the Pi Pico’s PIO subsystem, which is perfect for clocking out the signals for red, green, and blue along with HSYNC and VSYNC as needed. The Pico slots right into [Arnov’s] custom PCB, which makes it a cinch to hook everything up. Supporting hardware is minimal, requiring just a few resistors between the Pico and the DE-15 VGA connector. There’s also a nice LM317 regulator on board to supply power to everything. [Arnov] also whipped up a modified version of the VGA library from [Pancrea85], which allows the Pico to output VGA in a way that’s more accepted by more recent TFT displays as well as older CRTs. The system is demoed with a few basic Hello, World programs, as well as a neat recreation of Conway’s Game of Life.

If you want to get a Pi Pico hooked up to a big screen quickly, whipping up a board like this is a great way to go. If you’re wanting something more advanced, though, you could always explore DVI and HDMI on the same platform. Video after the break.

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A man's hand is holding a thin wooden board, which runs between two vertical metal plates. On the board are two glasses, one filled with water. A computer screen is behind all this, showing a series of white bars. The series of bars shows two peaks.

Using Capacitance For Extremely Sensitive Proximity Sensing

April 18, 2026 by 18 Comments

Capacitive displacement sensors span a wide range of resolution, from the touchscreen sensors which can only detect displacement as a binary state, all the way to the sensors in semiconductor fabs which measure down to nanometers. The sensor [Matthias Wandel] built with a Raspberry Pi Pico lands somewhere in the middle, providing both sensitive measurements and an absolute scale.

The idea is that the amount of overlap between two metal plates should be detectable by measuring the capacitance between them. Reaching any kind of usable resolution would require a very precise measure of capacitance, around the picofarad range. [Matthias] realized that the Pico’s GPIO pins have an inherent capacitance, and can have a pull-down resistor set, essentially creating an RC circuit. [Matthias] would set a pin to a high-level output, then switch it to an input. The amount of time the pin takes to switch from high to low indicates the RC constant, which includes the capacitance attached to the pin.

When attached to a metal plate, the Pico was sensitive enough to detect the plate’s capacitive coupling to [Matthias]’s hand through a thick wooden floor. To measure capacitance between two metal plates, the Pico measured how well a voltage signal applied to one plate was coupled to the other plate. This was sensitive enough to measure the slight change in the dielectric constant when [Matthias] waved a piece of ABS pipe between the two capacitor plates. Making actual position measurements was tricky, since capacitance changed with both X- and Z-axis shifts in the plates.

Digital calipers use similar capacitive sensors to make their measurements, as [Matthias] knows from his experiments in hacking them. If you’re interested in more details, check out this teardown of some cheap digital calipers.

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Making A 286 Think It’s Alive Again

March 1, 2026 by 8 Comments

[Nagy Krisztián] had an Intel 286 CPU, only… There was no motherboard to install it in. Perhaps not wanting the processor to be lonely, [Nagy] built a simulated system to bring the chip back to life.

Okay, 68 pins does look like a lot when you arrange them like that.

The concept is simple enough. [Nagy] merely intended to wire the 286 up to a Raspberry Pi Pico that could emulate other parts of a computer that it would normally expect to talk to. This isn’t so hard with an ancient CPU like the 286, which has just 68 pins compared to the 1000+ pins on modern CPUs. All it took was a PLCC-68 socket, an adapter PCB, a breadboard, and some MCP23s17 logic expanders to give the diminutive microcontroller enough I/O. With a bit of work, [Nagy] was able to get the Pi Pico running the 286, allowing it to execute a simple program that retrieves numbers from “memory” and writes them back in turn.

Notably, this setup won’t run the 286 at its full clock speed of 12 MHz, and it’s a long way off from doing anything complex like talking to peripherals or booting an OS. Still, it’s neat to see the old metal live again, even if it’s just rattling through a few simple machine instructions that don’t mean a whole lot. [Nagy] equates this project to The Matrix; you might also think of it as a brain in a jar. The 286 is not in a real computer; it’s just hooked up to a microcontroller stimulating its various pins in a way that is indistinguishable from its own perspective. Continue reading “Making A 286 Think It’s Alive Again” →

Let Hauntimator Steer Your Next Animatronic Display

February 27, 2026 by 2 Comments

Animatronic displays aren’t just for Halloween, and hackers today have incredible access to effective, affordable parts with which to make spectacles of light, sound, and movement. But the hardware is only half the battle. Getting everything synchronized properly can be a daunting task, so get a head start on your next holiday display with the Hauntimator by [1031-Systems].

Synchronizing control channels to audio is at the heart of solid animations.

After all, synchronizing movements, sound, and light by trial and error can get tiresome even in small setups. Anyone who makes such a display — and contemplates doing it twice — tends to quickly look into making things modular.

At its heart, Hauntimator works with a Raspberry Pi Pico-based controller board. The GUI makes it easy to create control channels for different hardware (for example, doing things like moving servos) and synchronize them to audio. Once an animation is validated, it gets uploaded to the control board where it runs itself. It’s open-source and designed to make plugins easy, so give it a look. There’s a video channel with some demonstrations of the tools that should fill in any blanks.

Intrigued by animatronics, but not sure where to begin? Get inspired by checking out this DIY set of servo-driven eyes, and see for yourself the benefits of smooth motor control for generating lifelike motion.

Making A Mountain Bike Data Acquisition System

January 18, 2026 by 14 Comments

Professional mountain bike racing is a rather bizarre sport. At the highest level, times between podiums will be less than a second, and countless hours of training and engineering go into those fractions of seconds. An all too important tool for the world cup race team is data acquisition systems (DAQ). In the right hands, they can offer an unparalleled suspension tune for a world cup racer. Sadly DAQs can cost thousands of dollars, so [sghctoma] built one using little more then potentiometer and LEGO. 

The hardware is a fairly simple task to solve. A simple Raspberry Pi Pico setup is used to capture potentiometer data. By some simple LEGO linkage and mounts, this data is correlated to the bikes’ wheel travel. Finally, everything is logged onto an SD card in a CSV format. Some buttons and a small AMOLED provide a simple user interface wrapped in a 3D printed case.

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