raspberry pi 2040

5 Articles

The board in question, with a Pi Pico soldered on, with old PCBs for macropads being used as captouch electrodes

Give Your Pi Pico Captouch Inputs For All Your Music Needs

March 31, 2024 by 11 Comments

Unlike many modern microcontrollers, RP2040 doesn’t come with a native capacitive touch peripheral. This doesn’t mean you can’t do it – the usual software-driven way works wonderfully, and only requires an external pullup resistor! In case you wanted a demonstration or you have a capacitive touch project in mind, this lighthearted video by [Jeremy Cook] is a must watch, and he’s got a healthy amount of resources for you in store, too!

In this video, [Jeremy] presents you with a KiCad schematic and an PCB design you can use to quickly add whole 23 capacitive touch sensing inputs to a Pi Pico! The board is flexible mechanically, easy to assemble as [Jeremy] demonstrates, and all the pins involved can still be used as regular GPIOs if you’d like. Plus, it’s fully open-source, can easily be assembled on your own, and available on Tindie too!

Of course, such a board doesn’t get created for no reason – [Jeremy] has a healthy amount of musical creations and nifty ideas to show off. We quite liked the trick of using old PCBs as capacitive touch sensing, using copper fills as electrodes – which has helped create an amusing “macropad of macropads”, and, there’s quite a bit more to see.

If capacitive touch projects ever struck a chord with you and you enjoy music-related hacking, [Jeremy]’s got a whole YouTube channel you ought to check out. Oh, and if one of the musical projects in the video caught your eye, it might just be the one we’ve featured previously! Continue reading “Give Your Pi Pico Captouch Inputs For All Your Music Needs” →

The Pi Pico replacement board in question, assembled, held diagonally in some type of holder

ProPico For Your Pro Pico Needs

January 3, 2024 by 6 Comments

Ever feel like the Pi Pico board could be doing way more given its footprint? Does it bother you that the RP2040’s ADC quality is even further decreased because of the noisy onboard switching regulator? Miffed about decisions like the MicroUSB socket, the 2MB flash, or lack of the reset button? [Dmytro] brings us an open-source Pi Pico design, sporting the same RP2040 and a fully compatible footprint, but adding a number of improvements to its surroundings.

There’s a good few additions, all of them hacker-friendly – [Dmytro] adds comfortably-spaced reset and boot buttons, a USB-C socket, a dedicated low-noise voltage reference for the ADC, one more LED, and an I2C EEPROM footprint socket that is compatible with FRAM chips. Everything worth preserving is preserved – the pinout stays the same, including the SWD connector, which now sports an extra RESET pin. The bottom side USB testpoints remain, with only the four testpoints changed for more useful signals. Last but not least, the switching regulator is replaced by the venerable 1117 – you lose the ability to power your Pico from two AAs, and the capacitor series resistor requirement isn’t great, but you can easily put one of the drop-in 1117 replacement regulators on there.

What’s great is that the design is fully open-source, with KiCad files available. Want to design your own Pi Pico footprint board, improve upon this one even further, or maybe make a more tailored one? Treat yourself to the GitHub repository! There’s also a pinout diagram and a KiCanvas schematic for all your tinkering needs. We’ve covered drop-in replacements for classic drawer-inhabiting parts like the Pi Zero, for the 7805 (twice!), the 6502 CPU, and even for the DE9 serial port connector. No matter the purpose, they’re always a joy to see.

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.

Showing a board with a Pi Pico plugged into it, a USB-A socket marked "USB host", and a character display that says "PASSED" referring to the board being the brains of a testing jig.

USB Host On RP2040 – With PIO

December 28, 2022 by 11 Comments

Folks from [Adafruit] are showing off a neat hack – USB host on RP2040, using the now-famous PIO peripheral. [Adafruit] builds a lot of RP2040 boards, and naturally, you gotta test them before you ship them to customers. They’ve been using very specific Teensies for that, and at some point, those became unobtainium. Based on the work of [sekigon-gonnoc] and with help of [Thach], they’ve made their TinyUSB library support bitbanging of USB over PIO, and successfully ported their test jig firmware to it!

The base Pico-PIO-USB repo by [sekigon-gonnoc] shows a pretty impressive state of affairs – with low-speed and full-speed USB host and full-speed USB device modes supported, and quite a few examples to get you started. [Adafruit]’s work integrates this code into their TinyUSB stack, specifically focusing on MST (mass storage) features – as this is what you need to program a RP2040. Of course, they also provide a mass storage example to boot!

Test jigs are pretty important to have when making multiple pieces of a board, and with RP2040 supporting more and more interfaces thanks to PIO, it sounds like the perfect chip for your next production testing-intended PCB. With the jig brains taken care of, you’ll want to look into building no less important mechanical part, and we’ve covered quite a few ways to sort that out – here’s an OpenSCAD script that generates lasercutting files out of KiCad boards, or a jig built out of scrap copperclad FR4, and a pretty extensive tutorial on making your own lasercuttable jigs, to boot.

Continue reading “USB Host On RP2040 – With PIO” →

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” →