pi pico

68 Articles

PCB mounted on 3D-printed holder, debug pins attached to Pi Pico on a breadboard. The battery is in the background, disconnected

Reverse Engineering E-Ink Price Tags

February 11, 2023 by 7 Comments

E-ink displays are great, but working with them can still be a bit tricky if you aren’t an OEM. [Jasper Devreker] got his hands on three e-ink shelf displays to reverse engineer.

After cracking the tag open, [Devreker] found a CC2510 microcontroller running the show. While the spec sheet shows a debug mode, this particular device has been debug locked making reading the device’s code problematic. Undaunted, he removed the decoupling capacitor from the DCOUPL pin and placed a MOSFET between it and the ground pin to perform a voltage glitch attack.

A Pi Pico was used to operate the MOSFET over PIO with the chip overclocked to 250 MHz to increase the precision and duration of the glitch. After some testing, a successful glitch pathway was found, but with only a 5% success rate. With two successive glitches in a row needed to read out a byte from the device, the process is not a fast one. Data pulled so far has shown to be valid code when fed into Ghidra, and this project page is being updated as progress continues.

If you want to delve further into hacking e-ink price tags, checkout this deep dive on the topic or this Universal E-paper Sniffer.

a Pi Pico on a breadboard, running a 7-segment counter gateware, with a 7-segment digit and a pushbutton next to the Pico

Want To Play With FPGAs? Use Your Pico!

December 31, 2022 by 21 Comments

Ever want to play with an FPGA, but don’t have the hardware? Now, if you have one of those ever-abundant Pi Picos, you can start playing with Verilog without getting an FPGA board. The FakePGA project by [tvlad1234], based on the Verilator toolkit, provides you with a way to compile Verilog into C++ for the RP2040. FakePGA even integrates RP2040 GPIOs so that they work as digital pins for the simulated GPIOs, making it a significant step up from computer-aided FPGA code simulation

[tvlad1234] provides instructions for setting this up with Linux – Windows, though untested, could theoretically run this through WSL. Maximum clock speed is 5KHz – not much, but way better than not having any hardware to test with. Everything you’d want is in the GitHub repo – setup instructions, Verilog code requirements, and a few configuration caveats to keep in mind.

We cover a lot of projects where FPGAs are used to emulate hardware of various kinds, from ISA cards to an entire Game Boy.  CPU emulation on FPGAs is basically the norm — it’s just something easy to do with the kind of power that an FPGA provides. Having emulation in the opposite direction is unusual,  though, we’ve seen FPGAs being emulated with FPGAs, so perhaps it was inevitable after all. Of course, if you have neither a Pico nor an FPGA, there’s always browser based emulators.

Continue reading “Want To Play With FPGAs? Use Your Pico!” →

The macropad PCB panel next to an assembled macropad

A Fun Low-Cost Start For Your Macropad Hobby

December 30, 2022 by 7 Comments

If you were ever looking for a small relaxing evening project that you could then use day-to-day, you gotta consider the Pico Hat Pad kit by [Natalie the Nerd]. It fits squarely within the Pi Pico form-factor, giving you two buttons, one rotary encoder and two individually addressable LEDs to play with. Initially, this macropad was intended as an under-$20 device that’s also a soldering practice kit, and [Natalie] has knocked it out of the park.

You build this macropad out of a stack of three PCBs — the middle one connecting the Pi Pico heart to the buttons, encoders and LEDs, and the remaining ones adding structural support and protection. All the PCBs fit together into a neat tab-connected panel — ready to be thrown into your favorite PCB service’s shopping cart. Under the hood, this macropad uses KMK, a CircuitPython-based keyboard firmware, with the configuration open-source. In fact everything is open-source, just the way we like it.

If you find yourself with an unexpected affinity for macropads after assembling this one, don’t panic. It’s quite a common side-effect. Fortunately, there are cures, and it’s no longer inevitable that you’ll go bananas about it. That said, if you’re fighting the urges to go bigger, you can try a different hand-wireable Pico-based macropad with three more keys. Come to find that one not enough? Here’s a 2×4 3D printable one.

Now, if you eventually find yourself reading every single Keebin’ With Kristina episode as soon as it comes out, you might be too far gone, and we’ll soon find you spending hundreds of dollars building tiny OLED screens into individual keys — in which case, make sure you document it and share it with us!

Continue reading “A Fun Low-Cost Start For Your Macropad Hobby” →

Foot Pedal Ups Vim Productivity, Brings Ergonomic Benefits

December 16, 2022 by 53 Comments

Vim is the greatest or the worst text editor of all time, depending on the tribe you’re in. Either way, members of both camps can appreciate this build from [Chris Price], which uses a foot pedal to ease operations for the user.

The basic concept was to use a pedal to enable switching between normal and insert modes. In Vim’s predecessor, vi, switching modes was easy, with the ESC key located neatly by the Q on the keyboard of the ADM-3A terminal. On modern keyboards, though, it’s a pain, and so a foot pedal is a desirable solution. In the Vim world, it’s referred to as a “Vim clutch.”

The build used a cheap pedal switch sourced from eBay, into which a Raspberry Pi Pico was installed. The Pico was hooked up to the switch contacts, and programmed to act as a USB HID device. When the pedal is pressed down, the Pico sends an “i” keypress to enter Vim’s insert mode. Releasing the pedal has the Pico send a “ESC” keypress to return to normal mode.

Those that use Vim on a regular basis would likely appreciate the productivity improvements of such a device. Plus, there’s some ergonomic benefits to not having to strain one’s hand over to reach the ESC key. Of course, it’s an old-school solution, but there’s still something so compelling and next-level about having a foot pedal hooked up to one’s dev rig.

Open World 3D Game Runs On The RP2040 Microcontroller

December 13, 2022 by 15 Comments

The Raspberry Pi RP2040 is versatile and cheap, but it’s by no means known as the most powerful microcontroller on the world. Regardless, it is capable of great things, as demonstrated by [Bernhard Strobl], who built a 3D open world game engine that runs on that very platform.

The graphics are simple, but with a compelling low-poly style.

The game engine itself is built to run on the Pimoroni PicoSystem, which is essentially a handheld gaming platform built around the RP2040 chip. The engine takes advantage of the multi-core nature of the RP2040, using the second core as a dedicated rasterizer to keep frames pumping out.

The basic game [Bernhard] built in the engine features 50 NPC characters and 50 further zombies, all running at the same time. Specs are impressive, with the engine’s included game simulating a “world” of 120 x 120 meters in size. As a maximum limit, the engine can handle a 2.56 x 2.56 km world, thanks to the use of 8-bit integers for directional data. However, limited storage space would make it difficult to achieve such a large world in practice.

We don’t get to see much of the gameplay in the YouTube video, but the quality of the graphics is impressive for such a cheap microcontroller. It seems within the bounds of possibility that an actual open-world game could be practical on the PicoSystem if only enough storage were available. Video after the break.

Continue reading “Open World 3D Game Runs On The RP2040 Microcontroller” →

An ortholinear keyboard with predominantly blank white keycaps. There are two red keycaps on the bottom outside corners. The center of the keyboard houses a large LCD in portrait orientation on a red PCB.

2022 Cyberdeck Contest: Keezyboost40 Is A Cyberdeck Masquerading As A Keyboard

October 20, 2022 by 5 Comments

There’s something to be said for über-powerful cyberdecks, but there’s also a certain appeal to less powerful decks squeezed into a tiny form factor. [Christian Lo] has designed a cyberdeck that looks like a simple ortholinear keyboard but is running a more flexible environment.

There are games and animations you can play on QMK, but [Lo] felt that a different framework would give him more flexibility to really stretch the limits of what this Raspberry Pi Pico-powered deck could do. He decided to go with a Rust-based firmware with the keyberon library and says, “it felt like I was in control of the firmware.” While the board is using Rust for now, [Lo] says he’s open to conversations about other firmware options to achieve his goals, like a virtual pet game for the board.

The PCB is described as “bog standard” with the possible exception of placing the Pi in a cutout on the board to keep things as low profile as possible. The trade-off comes in the form of reduced board rigidity and potentially increased strain on the connections to the microcontroller.

Looking for more cool cyberdecks? Check out the Winners of the 2022 Cyberdeck Contest or go see all the entries on the Contest Page.
Continue reading “2022 Cyberdeck Contest: Keezyboost40 Is A Cyberdeck Masquerading As A Keyboard” →

Self-Hosted Pi Pico Development

August 1, 2022 by 31 Comments

Older readers and those with an interest in retrocomputing may remember the days when a computer might well have booted into a BASIC interpreter. It was simultaneously a general purpose device that could run any software it would load, and also a development environment. Not something that can be said for today’s development boards which typically require a host computer on which to write code. Have we lost something along the way? Perhaps an answer to that question can be found in [lurk101]’s self-hosted development environment for the Raspberry Pi Pico.

It presents itself as a shell, with a flash file system, a port of the vi editor, and a C compiler. We might think of vi as being more at home on a UNIX-derived system, but in this case it’s a port of the vi included in BusyBox. Meanwhile the compiler comes from amacc project.

Of course, this still requires a terminal of some type which in practice will mean a host computer. But the feat is nevertheless an interesting one, and we can see that it might not be impossible given the Pico’s surprising versatility to being some of the terminal features onto the chip itself.

It’s worth noting that this isn’t the first attempt we’ve seen to put a command line interface on a development board.