pi pico

78 Articles

Modern Graphics Via DisplayLink For Your ISA-Era PC

May 31, 2026 by 13 Comments

The monitors used on older computers are now becoming difficult to find, as we doubt anything for MDA, CGA, Hercules, or EGA has been manufactured in decades. Even VGA, though there are plenty of surplus flat panels to be found, is not as ubiquitous as it once was. Where does that leave the retrocomputing enthusiast with an ISA PC and no screen? Perhaps [Ian Hanschen] has the answer with the PicoGraph, an ISA-to-USB-to-Displaylink adapter.

In hardware terms, it’s using a PicoMEM, a more general-purpose ISA card for emulating cards with a Pi Pico. The Pico hosts a USB DisplayLink adapter, which can connect to the screen of your choice. The software on the PicoMEM does the heavy lifting and provides MDA, Herc, EGA, and VGA support, as well as support for one of the 1990s Cirrus Logic SVGA chipsets. And yes, it appears to work with DOOM.

The practice of using 2020s microcontrollers to lend functionality to retrocomputers has revolutionised the art. We’ve seen many, with one of the more recent being a minimap add-on for an 8-bit Sinclair Spectrum.

CGA As You Have Never Seen It Before

May 17, 2026 by 11 Comments

An old-style graphics system as found on many 8-bit computers and on early PC graphics cards drew its characters by retrieving their bitmaps from a ROM. With a little sideways thinking, [GloriousCow] has exploited this process to make a CGA card perform graphical tricks it was never designed to do.

The CGA card clocks its character ROM continuously across the whole screen, even at the edges where nothing would normally be displayed. By placing the ROM in tandem with a Raspberry Pi Pico 2 they were able to use this ROM clocking as a synchronization signal, and inject whatever pixel data they chose.

The result is a CGA card that can display 60 Hz high-res graphics in text mode, albeit with a very retro one bit color depth. It can overlay the text and the graphics too, because the ROM is still present. One fun result of this is a bouncing DVD logo screensaver, on a DOS PC.

There’s a PCB and a promise of more, meanwhile we suggest you take a look at an impossible feat using a similar technique: NES Doom.

A Digital Audio Recorder For TOSLink

May 5, 2026 by 14 Comments

Every now and then in our travels we come upon a project with such an obvious need that it’s almost a surprise nobody has thought of doing it before. So it is with [Elehobica]’s project, an audio recorder for S/PDIF audio streams. It’s the device you could have used, years ago!

S/PDIF, or its optical fiber cousin TOSLINK, is the digital output you’ll find on the back of Hi-Fi equipment, it’s a serial encoding of an uncompressed digital audio data stream dating from the era when CDs were new. Its relative simplicity may be what’s given it longevity — it’s easy to implement so it plugs into pretty much everything.

Perhaps back in the day it might have been a pain for an 8-bit microprocessor to handle, but in 2026 it’s no bother for a Raspberry Pi Pico. The project is a small PCB with the Pico, a few interface components, and an SD card socket, and it sends what it hears on the input to the card as WAV files. We particularly like its smart sample rate and bit depth detection, and the way it cuts up tracks based on periods of silence. If you work with SPD/IF, this is going to be a useful tool.

Perhaps it could even be fed with a laser!

Digital Signal Processing On The Pi Pico

April 29, 2026 by 10 Comments

If you want to dabble in audio digital signal processing, you would probably think of grabbing a dedicated DSP chip. But thanks to [WeebLabs], you could just pick up a Pi Pico and use this full-featured DSP library.

The system supports plug-and-play USB audio interface that enumerates on Windows, Linux, macOS, and iOS. It can handle 16- or 24-bit inputs at up to 96 kHz. You can output up to four channels of 24-bit S/PDIF or I2S, or switch to an RP2350 to get eight channels. This lets you drive a DAC easily. There is also a direct output for a subwoofer that doesn’t require a DAC.

Each channel has a pre-amp, and a matrix mixer allows routing with different gains and phases for each input. An equalizer allows ten bands per channel. There are also modules to do volume leveling, loudness compensation, and headphone cross-feed.

The library uses both cores of the CPU and manages up to ten preset configurations. The Pico does get an overclock and uses a fixed-point representation. The Pico 2 (RP2350) doesn’t need overclocking and uses single-precision floating point.

Overall, this looks like a great base for any sort of soundcard-like project. We’ve seen DSP stunts on the Pico before. This might also make a nice base for other audio projects.

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.

Continue reading “Compact VGA Output Board For The Pi Pico” →

Storing Image Data As Analog Audio

February 12, 2026 by 15 Comments

Ham radio operators may be familiar with slow-scan television (SSTV) where an image is sent out over the airwaves to be received, decoded, and displayed on a computer monitor by other radio operators. It’s a niche mode that isn’t as popular as modern digital modes like FT8, but it still has its proponents. SSTV isn’t only confined to the radio, though. [BLANCHARD Jordan] used this encoding method to store digital images on a cassette tape in a custom-built tape deck for future playback and viewing.

The self-contained device first uses an ESP32 and its associated camera module to take a picture, with a screen that shows the current view of the camera as the picture is being taken. In this way it’s fairly similar to any semi-modern digital camera. From there, though, it starts to diverge from a typical digital camera. The digital image is converted first to analog and then stored as audio on a standard cassette tape, which is included in the module in lieu of something like an SD card.

To view the saved images, the tape is played back and the audio signal captured by an RP2040. It employs a number of methods to ensure that the reconstructed image is faithful to the original, but the final image displays the classic SSTV look that these images tend to have as a result of the analog media. As a bonus feature, the camera can use a serial connection to another computer to offload this final processing step.

We’ve been seeing a number of digital-to-analog projects lately, and whether that’s as a result of nostalgia for the 80s and 90s, as pushback against an increasingly invasive digital world, or simply an ongoing trend in the maker space, we’re here for it. Some of our favorites are this tape deck that streams from a Bluetooth source, applying that classic cassette sound, and this musical instrument which uses a cassette tape to generate all of its sounds.

A New Life For An Old Amplifier

January 14, 2026 by 23 Comments

An audio amplifier was once a fairly simple analogue device, but in recent decades a typical home entertainment amplifier will have expanded to include many digital functions. When these break they are often proprietary and not easy to repair, as was the case with a broken Pioneer surround-sound device given to [Boz]. It sat on the shelf for a few years until he had the idea of a jukebox for his ripped CDs, and his returning it to life with a new main board is something to behold.

Internally it’s a surprisingly modular design, meaning that the front panel with its VFD display and driver were intact and working, as were the class AB amplifier and its power supply. He had the service manual so reverse engineering was straightforward, thus out came the main board in favor of a replacement. He took the original connectors and a few other components, then designed a PCB to take them and a Raspberry Pi Pico and DAC. With appropriate MMBASIC firmware it looks as though it was originally made this way, a sense heightened by a look at the motherboard inside (ignoring a couple of bodges).

We like seeing projects like this one which revive broken devices, and this one is particularly special quality wise. We’re more used to seeing it with gaming hardware though.